UITableView的Group樣式下頂部空白處理
分組列表頭部空白處理UIView*view = [[UIViewalloc] initWithFrame:CGRectMake(0,0,0,0.1)];self.tableView.tableHeaderView = view;
UITableView的plain樣式下，取消區頭停滯效果
- (void)scrollViewDidScroll:(UIScrollView*)scrollView{? ? CGFloat sectionHeaderHeight = sectionHead.height;if (scrollView.contentOffset.y<=sectionHeaderHeight&&scrollView;.contentOffset.y>=0){scrollView.contentInset= UIEdgeInsetsMake(-scrollView.contentOffset.y,0,0,0);}? ? else if(scrollView.contentOffset.y>=sectionHeaderHeight){scrollView.contentInset= UIEdgeInsetsMake(-sectionHeaderHeight,0,0,0);}}
那個，其實，還是用Group樣式吧哈哈。
獲取某個view所在的控制器
- (UIViewController *)viewController{?
UIViewController *viewController =nil;? ?
UIResponder *next=self.nextResponder;
while(next)?
{
if([nextisKindOfClass:[UIViewControllerclass]])
{? ? ?
viewController = (UIViewController *)next;break;? ? ? ? }
next=next.nextResponder;? ?
}
return viewController;
}
兩種方法刪除NSUserDefaults所有記錄
//方法一NSString*appDomain = [[NSBundlemainBundle] bundleIdentifier];[[NSUserDefaultsstandardUserDefaults] removePersistentDomainForName:appDomain];
//方法二- (void)resetDefaults{NSUserDefaults* defs = [NSUserDefaultsstandardUserDefaults];
NSDictionary* dict = [defs dictionaryRepresentation];
for(id key in dict) ?
{ ? ?
? [defs removeObjectForKey:key]; ??
}?
? [defs synchronize];}
打印系統所有已注冊的字體名稱
#pragma mark - 打印系統所有已注冊的字體名稱
void enumerateFonts() {
for(NSString*family Namein[UIFont familyNames])? {
NSLog(@"%@",familyName);
NSArray*fontNames = [UIFont fontNamesForFamilyName:familyName];
for(NSString*fontNameinfontNames)? ?
? {
NSLog(@"\t|- %@",fontName);? ? ?
}?
}
}
取圖片某一像素點的顏色 在UIImage的分類中
- (UIColor*)colorAtPixel:(CGPoint)point{
if(!CGRectContainsPoint(CGRectMake(0.0f,0.0f,self.size.width,self.size.height), point))? ?
{
return nil;? ?
}
CGColor SpaceRefcolorSpace =CGColorSpaceCreateDeviceRGB();
int bytesPerPixel =4;
int bytesPerRow = bytesPerPixel *1;
NSUInteger bitsPerComponent =8;
unsignedchar pixelData[4] = {0,0,0,0};
CGContextRef context =CGBitmapContextCreate(pixelData,1,1,? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? bitsPerComponent,bytesPerRow,colorSpace,kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorSpace);
CGContextSetBlendMode(context, kCGBlendModeCopy);
CGContextTranslateCTM(context, -point.x, point.y -self.size.height);
CGContextDrawImage(context,CGRectMake(0.0f,0.0f,self.size.width,self.size.height),self.CGImage);
CGContextRelease(context);
CGFloat red? = (CGFloat)pixelData[0] /255.0f;
CGFloat green = (CGFloat)pixelData[1] /255.0f;
CGFloat blue? = (CGFloat)pixelData[2] /255.0f;
CGFloat alpha = (CGFloat)pixelData[3] /255.0f;
return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
}
字符串反轉
第一種：- (NSString*)reverseWordsInString:(NSString*)str{
NSMutableString*newString = [[NSMutableStringalloc] initWithCapacity:str.length];
for(NSIntegeri = str.length -1; i >=0; i --)? ?
{unicharch = [str characterAtIndex:i];? ? ?
? ?[newString appendFormat:@"%c", ch];? ? ? ?
}
return newString;
}
//第二種：- (NSString*)reverseWordsInString:(NSString*)str{
NSMutableString*reverString = [NSMutableStringstringWithCapacity:str.length];?
?[str enumerateSubstringsInRange:NSMakeRange(0, str.length) options:NSStringEnumerationReverse|NSStringEnumerationByComposedCharacterSequencesusingBlock:^(NSString*substring,NSRangesubstringRange,NSRangeenclosingRange,BOOL*stop) {? ? ? ? ?
[reverString appendString:substring];? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
}];
return reverString;
}
禁止鎖屏，
默認情況下，當設備一段時間沒有觸控動作時，iOS會鎖住屏幕。但有一些應用是不需要鎖屏的，比如視頻播放器。
[UIApplicationsharedApplication].idleTimerDisabled= YES;或[[UIApplicationsharedApplication]setIdleTimerDisabled:YES];
模態推出透明界面
UIViewController*vc = [[UIViewControlleralloc] init];
UINavigationController*na = [[UINavigationControlleralloc] initWithRootViewController:vc];
if([[[UIDevicecurrentDevice] systemVersion] floatValue] >=8.0){? ? na.modalPresentationStyle=UIModalPresentationOverCurrentContext;
}else{
self.modalPresentationStyle=UIModalPresentationCurrentContext;
}
[self presentViewController:na animated:YEScompletion:nil];
Xcode調試不顯示內存占用
editSCheme? 里面有個選項叫叫做enablezoombie Objects? 取消選中
顯示隱藏文件
//顯示defaults write com.apple.finderAppleShowAllFiles -bool truekillall Finder
//隱藏defaults write com.apple.finderAppleShowAllFiles -bool falsekillall Finder
字符串按多個符號分割
image.png
iOS跳轉到App Store下載應用評分
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"itms-apps://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?type=Purple+Software&id=APPID"]];
iOS 獲取漢字的拼音
+ (NSString*)transform:(NSString*)chinese{//將NSString裝換成NSMutableString
NSMutableString*pinyin = [chinese mutableCopy];//將漢字轉換為拼音(帶音標)
CFStringTransform((__bridgeCFMutableStringRef)pinyin,NULL, kCFStringTransformMandarinLatin,NO);
NSLog(@"%@", pinyin);//去掉拼音的音標
CFStringTransform((__bridgeCFMutableStringRef)pinyin,NULL,kCFStringTransformStripCombiningMarks,NO);
NSLog(@"%@", pinyin);//返回最近結果returnpinyin;
}
手動更改iOS狀態欄的顏色
- (void)setStatusBarBackgroundColor:(UIColor *)color{? ?
UIView *statusBar = [[[UIApplication sharedApplication]valueForKey:@"statusBarWindow"]valueForKey:@"statusBar"];
if([statusBar respondsToSelector:@selector(setBackgroundColor:)])? ? {? ? ?
? statusBar.backgroundColor = color; ? ? ?
}
}
判斷當前ViewController是push還是present的方式顯示的
NSArray*viewcontrollers=self.navigationController.viewControllers;if(viewcontrollers.count >1){if([viewcontrollers objectAtIndex:viewcontrollers.count -1] ==self)? ? {//push方式[self.navigationController popViewControllerAnimated:YES];? ? }}else{//present方式[selfdismissViewControllerAnimated:YEScompletion:nil];}
獲取實際使用的LaunchImage圖片
- (NSString*)getLaunchImageName{CGSizeviewSize =self.window.bounds.size;// 豎屏NSString*viewOrientation =@"Portrait";NSString*launchImageName =nil;NSArray* imagesDict = [[[NSBundlemainBundle] infoDictionary] valueForKey:@"UILaunchImages"];for(NSDictionary* dictinimagesDict)? ? {CGSizeimageSize =CGSizeFromString(dict[@"UILaunchImageSize"]);if(CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])? ? ? ? {? ? ? ? ? ? launchImageName = dict[@"UILaunchImageName"];? ? ? ? ? ? ? ? }? ? ? ? }returnlaunchImageName;}
iOS在當前屏幕獲取第一響應
UIWindow* keyWindow = [[UIApplicationsharedApplication] keyWindow];UIView* firstResponder = [keyWindow performSelector:@selector(firstResponder)];
判斷對象是否遵循了某協議
if([self.selectedControllerconformsToProtocol:@protocol(RefreshPtotocol)]){[self.selectedController performSelector:@selector(onTriggerRefresh)];}
判斷view是不是指定視圖的子視圖
BOOL isView= [textView isDescendantOfView:self.view];
NSArray 快速求總和 最大值 最小值 和 平均值
NSArray *array= [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil];CGFloat sum = [[arrayvalueForKeyPath:@"@sum.floatValue"] floatValue];CGFloat avg = [[arrayvalueForKeyPath:@"@avg.floatValue"] floatValue];CGFloatmax=[[arrayvalueForKeyPath:@"@max.floatValue"] floatValue];CGFloatmin=[[arrayvalueForKeyPath:@"@min.floatValue"] floatValue];NSLog(@"%f\n%f\n%f\n%f",sum,avg,max,min);
修改UITextField中Placeholder的文字顏色
[textField setValue:[UIColor redColor]forKeyPath:@"_placeholderLabel.textColor"];
關于NSDateFormatter的格式
G:公元時代，例如AD公元yy:年的后2位yyyy:完整年MM:月，顯示為1-12MMM:月，顯示為英文月份簡寫,如 JanMMMM:月，顯示為英文月份全稱，如 Janualydd:日，2位數表示，如02d:日，1-2位顯示，如2EEE:簡寫星期幾，如SunEEEE:全寫星期幾，如Sundayaa:上下午，AM/PMH:時，24小時制，0-23K：時，12小時制，0-11m:分，1-2位mm:分，2位s:秒，1-2位ss:秒，2位S:毫秒
獲取一個類的所有子類
+ (NSArray*) allSubclasses{? ? Class myClass = [selfclass];NSMutableArray*mySubclasses = [NSMutableArrayarray];unsignedintnumOfClasses;? ? Class *classes = objc_copyClassList(&numOfClasses;);for(unsignedintci =0; ci < numOfClasses; ci++)? ? {? ? ? ? Class superClass = classes[ci];do{? ? ? ? ? ? superClass = class_getSuperclass(superClass);? ? ? ? }while(superClass && superClass != myClass);if(superClass)? ? ? ? {? ? ? ? ? ? [mySubclasses addObject: classes[ci]];? ? ? ? }? ? }? ? free(classes);returnmySubclasses;}
監測IOS設備是否設置了代理，需要CFNetwork.framework
NSDictionary*proxySettings = (__bridgeNSDictionary*)(CFNetworkCopySystemProxySettings());NSArray*proxies = (__bridgeNSArray*)(CFNetworkCopyProxiesForURL((__bridgeCFURLRef_Nonnull)([NSURLURLWithString:@"http://www.baidu.com"]), (__bridgeCFDictionaryRef_Nonnull)(proxySettings)));NSLog(@"\n%@",proxies);NSDictionary*settings = proxies[0];NSLog(@"%@",[settings objectForKey:(NSString*)kCFProxyHostNameKey]);NSLog(@"%@",[settings objectForKey:(NSString*)kCFProxyPortNumberKey]);NSLog(@"%@",[settings objectForKey:(NSString*)kCFProxyTypeKey]);if([[settings objectForKey:(NSString*)kCFProxyTypeKey] isEqualToString:@"kCFProxyTypeNone"]){NSLog(@"沒代理");}else{NSLog(@"設置了代理");}
阿拉伯數字轉中文格式
+(NSString *)translation:(NSString *)arebic{? ? ? NSString *str = arebic;NSArray *arabic_numerals = @[@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"0"];NSArray *chinese_numerals = @[@"一",@"二",@"三",@"四",@"五",@"六",@"七",@"八",@"九",@"零"];NSArray *digits= @[@"個",@"十",@"百",@"千",@"萬",@"十",@"百",@"千",@"億",@"十",@"百",@"千",@"兆"];NSDictionary *dictionary= [NSDictionarydictionaryWithObjects:chinese_numeralsforKeys:arabic_numerals];NSMutableArray *sums = [NSMutableArray array];for (int i =0; i < str.length; i ++) {NSString *substr= [strsubstringWithRange:NSMakeRange(i,1)];NSString *a = [dictionaryobjectForKey:substr];NSString *b=digits[str.length-i-1];NSString *sum = [a stringByAppendingString:b];if ([a isEqualToString:chinese_numerals[9]])? ? ? ? {? ? ? ? ? ? if([bisEqualToString:digits[4]]||[bisEqualToString:digits[8]]){? ? ? ? ? ? ? ? sum =b;if ([[sums lastObject] isEqualToString:chinese_numerals[9]])? ? ? ? ? ? ? ? {? ? ? ? ? ? ? ? ? ? [sums removeLastObject];}? ? ? ? ? ? }else? ? ? ? ? ? {? ? ? ? ? ? ? ? sum = chinese_numerals[9];}? ? ? ? ? ? if ([[sums lastObject] isEqualToString:sum])? ? ? ? ? ? {? ? ? ? ? ? ? ? continue;}? ? ? ? }? ? ? ? [sumsaddObject:sum];}? ? NSString *sumStr = [sums componentsJoinedByString:@""];NSString *chinese = [sumStrsubstringToIndex:sumStr.length-1];NSLog(@"%@",str);NSLog(@"%@",chinese);return chinese;}
Base64編碼與NSString對象或NSData對象的轉換
// Create NSData objectNSData*nsdata = [@"iOS Developer Tips encoded in Base64"dataUsingEncoding:NSUTF8StringEncoding];// Get NSString from NSData object in Base64NSString*base64Encoded = [nsdata base64EncodedStringWithOptions:0];// Print the Base64 encoded stringNSLog(@"Encoded: %@", base64Encoded);// Let's go the other way...// NSData from the Base64 encoded strNSData*nsdataFromBase64String = [[NSDataalloc]? initWithBase64EncodedString:base64Encoded options:0];// Decoded NSString from the NSDataNSString*base64Decoded = [[NSStringalloc]? initWithData:nsdataFromBase64String encoding:NSUTF8StringEncoding];NSLog(@"Decoded: %@", base64Decoded);
取消UICollectionView的隱式動畫
UICollectionView在reloadItems的時候，默認會附加一個隱式的fade動畫，有時候很討厭，尤其是當你的cell是復合cell的情況下(比如cell使用到了UIStackView)。
下面幾種方法都可以幫你去除這些動畫
//方法一[UIViewperformWithoutAnimation:^{? ? [collectionViewreloadItemsAtIndexPaths:@[[NSIndexPathindexPathForItem:indexinSection:0]]];}];//方法二[UIViewanimateWithDuration:0animations:^{? ? [collectionViewperformBatchUpdates:^{? ? ? ? [collectionViewreloadItemsAtIndexPaths:@[[NSIndexPathindexPathForItem:indexinSection:0]]];? ? }completion:nil];}];//方法三[UIViewsetAnimationsEnabled:NO];[self.trackPanelperformBatchUpdates:^{? ? [collectionViewreloadItemsAtIndexPaths:@[[NSIndexPathindexPathForItem:indexinSection:0]]];}completion:^(BOOL finished) {? ? [UIViewsetAnimationsEnabled:YES];}];
讓Xcode的控制臺支持LLDB類型的打印
打開終端輸入三條命令:touch ~/.lldbinitechodisplay@import UIKit >> ~/.lldbinitechotargetstop-hookadd-o\"target stop-hook disable\">> ~/.lldbinit
CocoaPods pod install/pod update更新慢的問題
pod install --verbose--no-repo-updatepodupdate--verbose--no-repo-update如果不加后面的參數，默認會升級CocoaPods的spec倉庫，加一個參數可以省略這一步，然后速度就會提升不少
UIImage 占用內存大小
UIImage*image = [UIImageimageNamed:@"aa"];NSUIntegersize? =CGImageGetHeight(image.CGImage) *CGImageGetBytesPerRow(image.CGImage);
GCD timer定時器
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,0);dispatch_source_ttimer= dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER,0,0,queue);dispatch_source_set_timer(timer,dispatch_walltime(NULL,0),1.0*NSEC_PER_SEC,0);//每秒執行dispatch_source_set_event_handler(timer, ^{//@"倒計時結束，關閉"dispatch_source_cancel(timer);? ? dispatch_async(dispatch_get_main_queue(), ^{? ? });});dispatch_resume(timer);
圖片上繪制文字 寫一個UIImage的category
- (UIImage*)imageWithTitle:(NSString*)title fontSize:(CGFloat)fontSize{//畫布大小CGSizesize=CGSizeMake(self.size.width,self.size.height);//創建一個基于位圖的上下文UIGraphicsBeginImageContextWithOptions(size,NO,0.0);//opaque:NO? scale:0.0[selfdrawAtPoint:CGPointMake(0.0,0.0)];//文字居中顯示在畫布上NSMutableParagraphStyle* paragraphStyle = [[NSParagraphStyledefaultParagraphStyle] mutableCopy];? ? paragraphStyle.lineBreakMode =NSLineBreakByCharWrapping;? ? paragraphStyle.alignment=NSTextAlignmentCenter;//文字居中//計算文字所占的size,文字居中顯示在畫布上CGSizesizeText=[title boundingRectWithSize:self.size options:NSStringDrawingUsesLineFragmentOriginattributes:@{NSFontAttributeName:[UIFontsystemFontOfSize:fontSize]}context:nil].size;CGFloatwidth =self.size.width;CGFloatheight =self.size.height;CGRectrect =CGRectMake((width-sizeText.width)/2, (height-sizeText.height)/2, sizeText.width, sizeText.height);//繪制文字[title drawInRect:rect withAttributes:@{NSFontAttributeName:[UIFontsystemFontOfSize:fontSize],NSForegroundColorAttributeName:[UIColorwhiteColor],NSParagraphStyleAttributeName:paragraphStyle}];//返回繪制的新圖形UIImage*newImage=UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();returnnewImage;}
查找一個視圖的所有子視圖
- (NSMutableArray *)allSubViewsForView:(UIView *)view{? ? NSMutableArray *array= [NSMutableArray arrayWithCapacity:0];for(UIView *subViewinview.subviews)? ? {? ? ? ? [arrayaddObject:subView];if(subView.subviews.count >0)? ? ? ? {? ? ? ? ? ? [arrayaddObjectsFromArray:[self allSubViewsForView:subView]];? ? ? ? }? ? }returnarray;}
計算文件大小
//文件大小- (longlong)fileSizeAtPath:(NSString *)path{? ? NSFileManager *fileManager = [NSFileManager defaultManager];if([fileManagerfileExistsAtPath:path])? ? {longlongsize = [fileManagerattributesOfItemAtPath:patherror:nil].fileSize;returnsize;? ? }return0;}//文件夾大小- (longlong)folderSizeAtPath:(NSString *)path{? ? NSFileManager *fileManager = [NSFileManager defaultManager];longlongfolderSize =0;if([fileManagerfileExistsAtPath:path])? ? {? ? ? ? NSArray *childerFiles = [fileManagersubpathsAtPath:path];for(NSString *fileNameinchilderFiles)? ? ? ? {? ? ? ? ? ? NSString *fileAbsolutePath = [pathstringByAppendingPathComponent:fileName];if([fileManagerfileExistsAtPath:fileAbsolutePath])? ? ? ? ? ? {longlongsize = [fileManagerattributesOfItemAtPath:fileAbsolutePatherror:nil].fileSize;? ? ? ? ? ? ? ? folderSize += size;? ? ? ? ? ? }? ? ? ? }? ? }returnfolderSize;}
UIView設置部分圓角
你是不是也遇到過這樣的問題，一個button或者label，只要右邊的兩個角圓角，或者只要一個圓角。該怎么辦呢。這就需要圖層蒙版來幫助我們了
CGRectrect = view.bounds;CGSizeradio =CGSizeMake(30,30);//圓角尺寸UIRectCornercorner =UIRectCornerTopLeft|UIRectCornerTopRight;//這只圓角位置UIBezierPath*path = [UIBezierPathbezierPathWithRoundedRect:rect byRoundingCorners:corner cornerRadii:radio];CAShapeLayer*masklayer = [[CAShapeLayeralloc]init];//創建shapelayermasklayer.frame = view.bounds;masklayer.path = path.CGPath;//設置路徑view.layer.mask = masklayer;
取上整與取下整
floor(x),有時候也寫做Floor(x)，其功能是“下取整”，即取不大于x的最大整數 例如：x=3.14，floor(x)=3y=9.99999，floor(y)=9與floor函數對應的是ceil函數，即上取整函數。ceil函數的作用是求不小于給定實數的最小整數。ceil(2)=ceil(1.2)=cei(1.5)=2.00floor函數與ceil函數的返回值均為double型
計算字符串字符長度，一個漢字算兩個字符
//方法一：- (int)convertToInt:(NSString*)strtemp{intstrlength =0;char* p = (char*)[strtemp cStringUsingEncoding:NSUnicodeStringEncoding];for(inti=0; i<[strtemp lengthOfBytesUsingEncoding:NSUnicodeStringEncoding] ;i++)? ? {if(*p)? ? ? ? {? ? ? ? ? ? p++;? ? ? ? ? ? strlength++;? ? ? ? }else{? ? ? ? ? ? p++;? ? ? ? }? ? }returnstrlength;}//方法二：-(NSUInteger) unicodeLengthOfString: (NSString*) text{NSUIntegerasciiLength =0;for(NSUIntegeri =0; i < text.length; i++)? ? {unicharuc = [text characterAtIndex: i];? ? ? ? asciiLength += isascii(uc) ?1:2;? ? }returnasciiLength;}
給UIView設置圖片
UIImage*image = [UIImageimageNamed:@"image"];self.MYView.layer.contents = (__bridgeid_Nullable)(image.CGImage);self.MYView.layer.contentsRect =CGRectMake(0,0,0.5,0.5);
防止scrollView手勢覆蓋側滑手勢
[scrollView.panGestureRecognizerrequireGestureRecognizerToFail:self.navigationController.interactivePopGestureRecognizer];
去掉導航欄返回的back標題
[[UIBarButtonItemappearance]setBackButtonTitlePositionAdjustment:UIOffsetMake(0,-60)forBarMetrics:UIBarMetricsDefault];
字符串中是否含有中文
+ (BOOL)checkIsChinese:(NSString*)string{for(inti=0; i
dispatch_group的使用
dispatch_group_t dispatchGroup = dispatch_group_create();dispatch_group_enter(dispatchGroup);dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1* NSEC_PER_SEC)), dispatch_get_main_queue(), ^{? ? ? ? NSLog(@"第一個請求完成");? ? ? ? dispatch_group_leave(dispatchGroup);? ? });? ? dispatch_group_enter(dispatchGroup);? ? dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(10 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{? ? ? ? NSLog(@"第二個請求完成");dispatch_group_leave(dispatchGroup);});dispatch_group_notify(dispatchGroup, dispatch_get_main_queue(), ^(){? ? ? ? NSLog(@"請求完成");});
UITextField每四位加一個空格,實現代理
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{// 四位加一個空格if([stringisEqualToString:@""])? ? {// 刪除字符if((textField.text.length -2) %5==0)? ? ? ? {? ? ? ? ? ? textField.text= [textField.textsubstringToIndex:textField.text.length -1];? ? ? ? }returnYES;? ? }else{if(textField.text.length %5==0)? ? ? ? {? ? ? ? ? ? textField.text= [NSString stringWithFormat:@"%@ ", textField.text];? ? ? ? }? ? }returnYES;}
獲取私有屬性和成員變量 #import
//獲取私有屬性 比如設置UIDatePicker的字體顏色- (void)setTextColor{//獲取所有的屬性，去查看有沒有對應的屬性unsignedintcount =0;? ? objc_property_t *propertys = class_copyPropertyList([UIDatePickerclass], &count);for(inti =0;i < count;i ++)? ? {//獲得每一個屬性objc_property_t property = propertys[i];//獲得屬性對應的nsstringNSString*propertyName = [NSStringstringWithCString:property_getName(property) encoding:NSUTF8StringEncoding];//輸出打印看對應的屬性NSLog(@"propertyname = %@",propertyName);if([propertyName isEqualToString:@"textColor"])? ? ? ? {? ? ? ? ? ? [datePicker setValue:[UIColorwhiteColor] forKey:propertyName];? ? ? ? }? ? }}
//獲得成員變量 比如修改UIAlertAction的按鈕字體顏色unsignedintcount =0;? ? Ivar *ivars = class_copyIvarList([UIAlertActionclass], &count);for(inti =0;i < count;i ++)? ? {? ? ? ? Ivar ivar = ivars[i];NSString*ivarName = [NSStringstringWithCString:ivar_getName(ivar) encoding:NSUTF8StringEncoding];NSLog(@"uialertion.ivarName = %@",ivarName);if([ivarName isEqualToString:@"_titleTextColor"])? ? ? ? {? ? ? ? ? ? [alertOk setValue:[UIColorblueColor] forKey:@"titleTextColor"];? ? ? ? ? ? [alertCancel setValue:[UIColorpurpleColor] forKey:@"titleTextColor"];? ? ? ? }? ? }
獲取手機安裝的應用
Class c =NSClassFromString(@"LSApplicationWorkspace");ids = [(id)c performSelector:NSSelectorFromString(@"defaultWorkspace")];NSArray*array = [s performSelector:NSSelectorFromString(@"allInstalledApplications")];for(iditeminarray){NSLog(@"%@",[item performSelector:NSSelectorFromString(@"applicationIdentifier")]);//NSLog(@"%@",[item performSelector:NSSelectorFromString(@"bundleIdentifier")]);NSLog(@"%@",[item performSelector:NSSelectorFromString(@"bundleVersion")]);NSLog(@"%@",[item performSelector:NSSelectorFromString(@"shortVersionString")]);}
判斷兩個日期是否在同一周 寫在NSDate的category里面
- (BOOL)isSameDateWithDate:(NSDate*)date{//日期間隔大于七天之間返回NOif(fabs([selftimeIntervalSinceDate:date]) >=7*24*3600)? ? {returnNO;? ? }NSCalendar*calender = [NSCalendarcurrentCalendar];? ? calender.firstWeekday =2;//設置每周第一天從周一開始//計算兩個日期分別為這年第幾周NSUIntegercountSelf = [calender ordinalityOfUnit:NSCalendarUnitWeekdayinUnit:NSCalendarUnitYearforDate:self];NSUIntegercountDate = [calender ordinalityOfUnit:NSCalendarUnitWeekdayinUnit:NSCalendarUnitYearforDate:date];//相等就在同一周，不相等就不在同一周returncountSelf == countDate;}
應用內打開系統設置界面
//iOS8之后[[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];//如果App沒有添加權限，顯示的是設定界面。如果App有添加權限（例如通知），顯示的是App的設定界面。
//iOS8之前//先添加一個url type如下圖，在代碼中調用如下代碼,即可跳轉到設置頁面的對應項[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=WIFI"]];可選值如下：About — prefs:root=General&path=AboutAccessibility — prefs:root=General&path=ACCESSIBILITYAirplane Mode On — prefs:root=AIRPLANE_MODEAuto-Lock— prefs:root=General&path=AUTOLOCKBrightness — prefs:root=BrightnessBluetooth — prefs:root=General&path=BluetoothDate&Time— prefs:root=General&path=DATE_AND_TIMEFaceTime — prefs:root=FACETIMEGeneral— prefs:root=GeneralKeyboard — prefs:root=General&path=KeyboardiCloud — prefs:root=CASTLEiCloudStorage&Backup— prefs:root=CASTLE&path=STORAGE_AND_BACKUPInternational — prefs:root=General&path=INTERNATIONALLocation Services — prefs:root=LOCATION_SERVICESMusic — prefs:root=MUSICMusic Equalizer — prefs:root=MUSIC&path=EQMusic VolumeLimit— prefs:root=MUSIC&path=VolumeLimitNetwork — prefs:root=General&path=NetworkNike + iPod — prefs:root=NIKE_PLUS_IPODNotes — prefs:root=NOTESNotification — prefs:root=NOTIFICATI*****_IDPhone — prefs:root=PhonePhotos — prefs:root=PhotosProfile — prefs:root=General&path=ManagedConfigurationListReset— prefs:root=General&path=ResetSafari — prefs:root=SafariSiri — prefs:root=General&path=AssistantSounds — prefs:root=SoundsSoftwareUpdate— prefs:root=General&path=SOFTWARE_UPDATE_LINKStore— prefs:root=STORETwitter — prefs:root=TWITTERUsage— prefs:root=General&path=USAGEVPN — prefs:root=General&path=Network/VPNWallpaper — prefs:root=WallpaperWi-Fi — prefs:root=WIFI
Image.png
屏蔽觸發事件，2秒后取消屏蔽
[[UIApplicationsharedApplication] beginIgnoringInteractionEvents];dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2* NSEC_PER_SEC)), dispatch_get_main_queue(), ^{? ? [[UIApplicationsharedApplication] endIgnoringInteractionEvents]});
動畫暫停再開始
-(void)pauseLayer:(CALayer*)layer{? ? CFTimeIntervalpausedTime= [layer convertTime:CACurrentMediaTime() fromLayer:nil];layer.speed =0.0;layer.timeOffset =pausedTime;}-(void)resumeLayer:(CALayer *)layer{? ? CFTimeIntervalpausedTime= [layer timeOffset];layer.speed =1.0;layer.timeOffset =0.0;layer.beginTime=0.0;CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] -pausedTime;layer.beginTime= timeSincePause;}
fillRule原理
Image.png
iOS中數字的格式化
//通過NSNumberFormatter，同樣可以設置NSNumber輸出的格式。例如如下代碼：NSNumberFormatter*formatter = [[NSNumberFormatteralloc] init];formatter.numberStyle =NSNumberFormatterDecimalStyle;NSString*string = [formatter stringFromNumber:[NSNumbernumberWithInt:123456789]];NSLog(@"Formatted number string:%@",string);//輸出結果為：[1223:403] Formatted number string:123,456,789//其中NSNumberFormatter類有個屬性numberStyle，它是一個枚舉型，設置不同的值可以輸出不同的數字格式。該枚舉包括：typedefNS_ENUM(NSUInteger,NSNumberFormatterStyle) {NSNumberFormatterNoStyle= kCFNumberFormatterNoStyle,NSNumberFormatterDecimalStyle= kCFNumberFormatterDecimalStyle,NSNumberFormatterCurrencyStyle= kCFNumberFormatterCurrencyStyle,NSNumberFormatterPercentStyle= kCFNumberFormatterPercentStyle,NSNumberFormatterScientificStyle= kCFNumberFormatterScientificStyle,NSNumberFormatterSpellOutStyle= kCFNumberFormatterSpellOutStyle};//各個枚舉對應輸出數字格式的效果如下：其中第三項和最后一項的輸出會根據系統設置的語言區域的不同而不同。[1243:403] Formatted number string:123456789[1243:403] Formatted number string:123,456,789[1243:403] Formatted number string:￥123,456,789.00[1243:403] Formatted number string:-539,222,988%[1243:403] Formatted number string:1.23456789E8[1243:403] Formatted number string:一億二千三百四十五萬六千七百八十九
如何獲取WebView所有的圖片地址，
在網頁加載完成時，通過js獲取圖片和添加點擊的識別方式
//UIWebView- (void)webViewDidFinishLoad:(UIWebView*)webView{//這里是js，主要目的實現對url的獲取staticNSString*constjsGetImages =@"function getImages(){\
var objs = document.getElementsByTagName(\"img\");\
var imgScr = '';\
for(var i=0;i
imgScr = imgScr + objs[i].src + '+';\
};\
return imgScr;\
};";? ? [webView stringByEvaluatingJavaScriptFromString:jsGetImages];//注入js方法NSString*urlResult = [webView stringByEvaluatingJavaScriptFromString:@"getImages()"];NSArray*urlArray = [NSMutableArrayarrayWithArray:[urlResult componentsSeparatedByString:@"+"]];//urlResurlt 就是獲取到得所有圖片的url的拼接；mUrlArray就是所有Url的數組}
//WKWebView- (void)webView:(WKWebView*)webView didFinishNavigation:(null_unspecifiedWKNavigation*)navigation{staticNSString*constjsGetImages =@"function getImages(){\
var objs = document.getElementsByTagName(\"img\");\
var imgScr = '';\
for(var i=0;i
imgScr = imgScr + objs[i].src + '+';\
};\
return imgScr;\
};";? ? [webView evaluateJavaScript:jsGetImages completionHandler:nil];? ? [webView evaluateJavaScript:@"getImages()"completionHandler:^(id_Nullable result,NSError* _Nullable error) {NSLog(@"%@",result);? ? }];}
獲取到webview的高度
CGFloat height= [[self.webView stringByEvaluatingJavaScriptFromString:@"document.body.offsetHeight"] floatValue];
navigationBar變為純透明
//第一種方法//導航欄純透明[self.navigationBar setBackgroundImage:[UIImagenew] forBarMetrics:UIBarMetricsDefault];//去掉導航欄底部的黑線self.navigationBar.shadowImage = [UIImagenew];//第二種方法[[self.navigationBar subviews] objectAtIndex:0].alpha =0;
tabBar同理
[self.tabBar setBackgroundImage:[UIImagenew]];self.tabBar.shadowImage = [UIImagenew];
navigationBar根據滑動距離的漸變色實現
//第一種- (void)scrollViewDidScroll:(UIScrollView*)scrollView{CGFloatoffsetToShow =200.0;//滑動多少就完全顯示CGFloatalpha =1- (offsetToShow - scrollView.contentOffset.y) / offsetToShow;? ? [[self.navigationController.navigationBar subviews] objectAtIndex:0].alpha = alpha;}
//第二種- (void)scrollViewDidScroll:(UIScrollView*)scrollView{CGFloatoffsetToShow =200.0;CGFloatalpha =1- (offsetToShow - scrollView.contentOffset.y) / offsetToShow;? ? [self.navigationController.navigationBar setShadowImage:[UIImagenew]];? ? [self.navigationController.navigationBar setBackgroundImage:[selfimageWithColor:[[UIColororangeColor]colorWithAlphaComponent:alpha]] forBarMetrics:UIBarMetricsDefault];}//生成一張純色的圖片- (UIImage*)imageWithColor:(UIColor*)color{CGRectrect =CGRectMake(0.0f,0.0f,1.0f,1.0f);UIGraphicsBeginImageContext(rect.size);CGContextRefcontext =UIGraphicsGetCurrentContext();CGContextSetFillColorWithColor(context, [colorCGColor]);CGContextFillRect(context, rect);UIImage*theImage =UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();returntheImage;}
iOS 開發中一些相關的路徑
模擬器的位置:/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs 文檔安裝位置:/Applications/Xcode.app/Contents/Developer/Documentation/DocSets插件保存路徑:~/Library/ApplicationSupport/Developer/Shared/Xcode/Plug-ins自定義代碼段的保存路徑:~/Library/Developer/Xcode/UserData/CodeSnippets/如果找不到CodeSnippets文件夾，可以自己新建一個CodeSnippets文件夾。描述文件路徑~/Library/MobileDevice/Provisioning Profiles
navigationItem的BarButtonItem如何緊靠屏幕右邊界或者左邊界？
一般情況下，右邊的item會和屏幕右側保持一段距離：
image.png
下面是通過添加一個負值寬度的固定間距的item來解決，也可以改變寬度實現不同的間隔：
UIImage*img = [[UIImageimageNamed:@"icon_cog"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];//寬度為負數的固定間距的系統itemUIBarButtonItem*rightNegativeSpacer = [[UIBarButtonItemalloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpacetarget:nilaction:nil];[rightNegativeSpacer setWidth:-15];UIBarButtonItem*rightBtnItem1 = [[UIBarButtonItemalloc]initWithImage:img style:UIBarButtonItemStylePlaintarget:selfaction:@selector(rightButtonItemClicked:)];UIBarButtonItem*rightBtnItem2 = [[UIBarButtonItemalloc]initWithImage:img style:UIBarButtonItemStylePlaintarget:selfaction:@selector(rightButtonItemClicked:)];self.navigationItem.rightBarButtonItems = @[rightNegativeSpacer,rightBtnItem1,rightBtnItem2];
image.png
NSString進行URL編碼和解碼
NSString *string= @"http://abc.com?aaa=你好&bbb=tttee";//編碼 打印：http://abc.com?aaa=%E4%BD%A0%E5%A5%BD&bbb=ttteestring= [stringstringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];//解碼 打印：http://abc.com?aaa=你好&bbb=ttteestring= [stringstringByRemovingPercentEncoding];
UIWebView設置User-Agent。
//設置NSDictionary*dic = @{@"UserAgent":@"your UserAgent"};[[NSUserDefaultsstandardUserDefaults] registerDefaults:dic];//獲取NSString*agent = [self.WebView stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"];
獲取硬盤總容量與可用容量:
NSFileManager*fileManager = [NSFileManagerdefaultManager];NSDictionary*attributes = [fileManager attributesOfFileSystemForPath:NSHomeDirectory() error:nil];NSLog(@"容量%.2fG",[attributes[NSFileSystemSize] doubleValue] / (powf(1024,3)));NSLog(@"可用%.2fG",[attributes[NSFileSystemFreeSize] doubleValue] / powf(1024,3));
獲取UIColor的RGBA值
UIColor*color = [UIColorcolorWithRed:0.2green:0.3blue:0.9alpha:1.0];constCGFloat*components =CGColorGetComponents(color.CGColor);NSLog(@"Red: %.1f", components[0]);NSLog(@"Green: %.1f", components[1]);NSLog(@"Blue: %.1f", components[2]);NSLog(@"Alpha: %.1f", components[3]);
修改textField的placeholder的字體顏色、大小
[self.textField setValue:[UIColor redColor]forKeyPath:@"_placeholderLabel.textColor"];[self.textField setValue:[UIFont boldSystemFontOfSize:16]forKeyPath:@"_placeholderLabel.font"];
AFN移除JSON中的NSNull
AFJSONResponseSerializer *response = [AFJSONResponseSerializer serializer];response.removesKeysWithNullValues = YES;
ceil()和floor()
ceil()功 能：返回大于或者等于指定表達式的最小整數
floor()功 能：返回小于或者等于指定表達式的最大整數
UIWebView里面的圖片自適應屏幕
在webView加載完的代理方法里面這樣寫：
- (void)webViewDidFinishLoad:(UIWebView *)webView{? ? NSString *js= @"function imgAutoFit() { \
var imgs = document.getElementsByTagName('img'); \
for (var i = 0; i < imgs.length; ++i) { \
var img = imgs[i]; \
img.style.maxWidth = %f; \
} \
}";js= [NSString stringWithFormat:js,[UIScreen mainScreen].bounds.size.width-20];[webView stringByEvaluatingJavaScriptFromString:js];[webView stringByEvaluatingJavaScriptFromString:@"imgAutoFit()"];}
持續更新中……。
本文轉自：iOS_小松哥
