自定義視圖
自定義視圖：系統標準UI之外，自己組合而出的新的視圖。
自定義視圖的優點:
iOS提供了很多UI組件，借助它們我們可以實現不同的功能。盡管如此，實際開發中，我們還需自定義視圖。積累自己的代碼庫,方便開發。自己封裝的視圖，能像系統UI控件一樣，用于別的項目中，能大大降低開發成本，提高開發效率。
高質量代碼的特點:可復用,可移植,精煉等。(高內聚,低耦合)
自定義視圖步驟
根據需求的不同，自定義視圖繼承的類也有所不同。一般自定義的視圖會繼承于UIView。以下是自定義視圖的要點：
創建一個UIView子類 ：@interface LTView : UIView
在類的初始化方法中添加子視圖。
[self addSubview:_leftLabel];
[self addSubview:_rightField]；
類的.h文件提供一些接口（方法），便于外界操作子視圖。
@property(nonatomic, retain)UILabel *leftLabel;//左側label
@property(nonatomic, retain)UITextField *rightField;//右側文本框
此時的LTView就變成了一個具有label和textField的視圖了。
LTView的理解
把Label和Textfield封裝到LTView中，在一定程度上簡化了我們的代碼。
往往我們需要對LTView中的Label或者Textfield進行一定的控制，比如：設置Label 的text，獲取Textfield的text，給Textfield指定delegate，設置textColor等。
為了方便外界操作Label和Textfield，因此我們要將這兩個屬性聲明在.h文件里。
//創建LTView對象
LTView *usernameView = [[LTView alloc]initWithFrame:CGRectMake(40,
100, 300, 50)];
usernameView.leftLabel.text = @"用戶名:";
usernameView.rightField.placeholder = @"請輸入用戶名";
[usernameView.rightField becomeFirstResponder];
[backView addSubview:usernameView];//backView是LTView添加到的父視圖
[usernameView release];
下面舉個小例子 把倆個filed 封裝在一個View上
第一步在.h中定義屬性，方便外界訪問
#import <UIKit/UIKit.h>
@interface MyInPutView : UIView
@property (nonatomic , retain) UITextField * usernameFiled;
@property(nonatomic,retain) UITextField * passwordFiled;
@end
第二步在.m 文件中具體封裝
#import "MyInPutView.h"
@interface MyInPutView ()<UITextFieldDelegate>
@end
@implementation MyInPutView
-(instancetype)initWithFrame:(CGRect)frame{
self = [super initWithFrame:frame];
if (self) {
UIImageView *userNameImageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"icon_username.png"] highlightedImage:[UIImage imageNamed:@"icon_username_select.png"]];
userNameImageView.frame = CGRectMake(0, 0, 40, 40);
userNameImageView.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.8f]; self.usernameFiled = [[UITextField alloc]initWithFrame:CGRectMake(0, 0, self.frame.size.width, frame.size.height/2-1)];
self.usernameFiled .backgroundColor =[UIColor colorWithRed:0 green:0 blue:0 alpha:0.3];
self.usernameFiled.leftView = userNameImageView;
self.usernameFiled.leftViewMode = UITextFieldViewModeAlways;
self.usernameFiled.delegate =self;
[self addSubview:self.usernameFiled];
UIImageView *passwordImageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"icon_password.png"] highlightedImage:[UIImage imageNamed:@"icon_password_select.png"]];
passwordImageView.frame = CGRectMake(0, 0, 40, 40);
passwordImageView.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.8f];
self.passwordFiled =[[UITextField alloc]initWithFrame:CGRectMake(0, self.usernameFiled.frame.size.height+2, self.usernameFiled.frame.size.width, self.usernameFiled.frame.size.height)]; self.passwordFiled .backgroundColor =[UIColor colorWithRed:0 green:0 blue:0 alpha:0.3f];
self. passwordFiled.leftView = passwordImageView;
self. passwordFiled.leftViewMode = UITextFieldViewModeAlways;
self.passwordFiled .delegate =self;
[self addSubview:self.passwordFiled];
}
return self ;
}
-(void)textFieldDidBeginEditing:(UITextField *)textField{
UIImageView * leftView = (UIImageView *)textField.leftView;
leftView.highlighted = YES;
}
-(void)textFieldDidEndEditing:(UITextField *)textField{
UIImageView * leftView = (UIImageView *)textField.leftView;
leftView.highlighted = NO;
}
@end
第三步在.min 中調用分裝的View
#import "ViewController.h"
#import "MyInPutView.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
MyInPutView *myInputView = [[MyInPutView alloc]initWithFrame:CGRectMake(40, 100, self.view.frame.size.width-40*2,82)];
myInputView.layer .cornerRadius =8.0f;//給myInputView設置圓角
myInputView.layer.masksToBounds =YES;//在myInputView上添加，不能超出圓角
[self.view addSubview:myInputView];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
