1.用block改写UIButton点击事件
在这里给给出两种方式.
(1)自定义BlockButton,在初始化的时候给出按钮的样式(自定义)
自定义一个BlockButton继承UIButton，然后在里面用
addTarget:(id)target action:(SEL)action forControlEvents:(UIControlEvents)controlEvents
这个方法触发block.
MyBlockButton.h
1 #import <UIKit/UIKit.h> 2 3 @class MyBlockButton; // 此处一定要声明 4 typedef void(^TouchBlock)(MyBlockButton *button); 5 6 @interface MyBlockButton : UIButton 7 8 @property (copy, nonatomic) TouchBlock block; 9 10 @end
MyBlockButton.m
1 #import "MyBlockButton.h" 2 3 @implementation MyBlockButton 4 5 -(instancetype)initWithFrame:(CGRect)frame 6 { 7 self = [super initWithFrame:frame]; 8 9 if (self) {10 // 按钮边框美化11 self.layer.borderWidth = 1;12 self.layer.borderColor = [UIColor lightGrayColor].CGColor;13 self.layer.cornerRadius = 3;14 self.layer.masksToBounds = YES;15 16 // 为按钮添加阴影17 self.layer.shadowColor = [UIColor blackColor].CGColor;18 self.layer.shadowOffset = CGSizeMake(3, 3);19 self.layer.shadowRadius = 3;20 21 // 调用此方法以触发block22 [self addTarget:self action:@selector(clickAction:) forControlEvents:UIControlEventTouchUpInside];23 }24 return self;25 }26 27 - (void)clickAction:(MyBlockButton *)button28 {29 _block(button);30 }31 32 @end
ViewController.h里面没有添加任何代码
ViewController.m
1 #import "ViewController.h" 2 #import "MyBlockButton.h" 3 4 @interface ViewController () 5 6 @end 7 8 @implementation ViewController 9 10 - (void)viewDidLoad {11 [super viewDidLoad];12 13 // 创建一个"确定按钮"14 MyBlockButton *button = [[MyBlockButton alloc]initWithFrame:CGRectMake(35, 100, 260, 30)];15 [button setTitle:@"确定" forState:UIControlStateNormal];16 [button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];17 button.backgroundColor = [UIColor orangeColor];18 [button setBlock:^(MyBlockButton *blockButton) {19 NSLog(@"按钮被点击了");20 }];21 [self.view addSubview:button];22 23 // 创建三个数字按钮24 for (int i = 1; i <= 3; i ++) {25 MyBlockButton *btn = [[MyBlockButton alloc]initWithFrame:CGRectMake(70 * i, 200, 60, 30)];26 [btn setTitle:[NSString stringWithFormat:@"%d",i] forState:UIControlStateNormal];27 [btn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];28 btn.backgroundColor = [UIColor redColor];29 btn.block = ^(MyBlockButton *blockBtn) {30 NSLog(@"按钮%d被点击了",i);31 };32 33 [self.view addSubview:btn];34 }35 }36 37 - (void)didReceiveMemoryWarning {38 [super didReceiveMemoryWarning];39 // Dispose of any resources that can be recreated.40 }41 42 @end
其运行效果如下:
(2)接下来给出的方法中,使用自定义方法调用block;继承自UIButton,在初始化使用的时候还需要设置其样式.
MyButtonBlock.h
1 #import <UIKit/UIKit.h> 2 3 typedef void(^TouchBlock)(UIButton *button); 4 5 @interface MyButtonBlock : UIButton 6 7 @property (copy, nonatomic) TouchBlock block; 8 9 // 自定义方法,调用block10 - (void)clikAction:(TouchBlock)block;11 12 @end
MyButtonBlock.m
1 #import "MyButtonBlock.h" 2 3 @implementation MyButtonBlock 4 5 - (void)clikAction:(TouchBlock)block 6 { 7 _block = block; 8 // 调用此方法以触发block 9 [self addTarget:self action:@selector(clickButton:) forControlEvents:UIControlEventTouchUpInside];10 }11 12 - (void)clickButton:(UIButton *)button13 {14 _block(button);15 }16 17 @end
ViewController.h里面没有添加任何代码
ViewController.m
1 #import "ViewController.h" 2 #import "MyButtonBlock.h" 3 4 @interface ViewController () 5 6 @end 7 8 @implementation ViewController 9 10 - (void)viewDidLoad {11 [super viewDidLoad];12 13 MyButtonBlock *buttonBlock = [MyButtonBlock buttonWithType:UIButtonTypeCustom];14 buttonBlock.frame = CGRectMake(35, 100, 300, 30);15 [buttonBlock setTitle:@"确定" forState:UIControlStateNormal];16 [buttonBlock setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];17 buttonBlock.backgroundColor = [UIColor orangeColor];18 19 [buttonBlock clikAction:^(UIButton *button) {20 NSLog(@"按钮被点击了!");21 }];22 23 [self.view addSubview:buttonBlock];24 }25 26 - (void)didReceiveMemoryWarning {27 [super didReceiveMemoryWarning];28 // Dispose of any resources that can be recreated.29 }30 31 @end
其运行效果如下:
2.用block改写UIButton点击事件和UIAlerView的代理
下面再改写Alert这个控件，思路与改写UIButton的点击事件的第二种方法是一样的，在自定义的Alert里面用block触发点击事件，而在Alert定义的代码里执行事件触发的行为.
MyAlertViewBlock.h
1 #import <UIKit/UIKit.h> 2 3 typedef void(^TouchBlock)(NSInteger buttonIndex); 4 5 @interface MyAlertViewBlock : UIAlertView 6 7 @property (copy, nonatomic) TouchBlock block; 8 9 // 自定义初始化方法10 - (instancetype)initWithTitle:(NSString *)title11 message:(NSString *)message12 cancelButtonTitle:(NSString *)cancelButtonTitle13 otherButtonTitles:(NSString *)otherButtonTitles14 andTouchBlock:(TouchBlock)block;15 16 @end
MyAlertViewBlock.m
1 #import "MyAlertViewBlock.h" 2 3 @implementation MyAlertViewBlock 4 5 - (instancetype)initWithTitle:(NSString *)title message:(NSString *)message cancelButtonTitle:(NSString *)cancelButtonTitle otherButtonTitles:(NSString *)otherButtonTitles andTouchBlock:(TouchBlock)block 6 { 7 // 先初始化父类的方法 8 self = [super initWithTitle:title message:message delegate:self cancelButtonTitle:cancelButtonTitle otherButtonTitles:otherButtonTitles, nil]; 9 if (self) {10 self.block = block;11 }12 return self;13 }14 15 #pragma mark - UIAlertViewDelegate(这只是一个提示,不需要签订代理协议)16 - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex17 {18 _block(buttonIndex);19 }20 21 @end
ViewController.h里面没有添加任何代码
ViewController.m
1 #import "ViewController.h" 2 #import "MyAlertViewBlock.h" 3 4 @interface ViewController () 5 6 @end 7 8 @implementation ViewController 9 10 - (void)viewDidLoad {11 [super viewDidLoad];12 13 // 创建一个UIButton(用于弹出UIAlertView)14 UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];15 button.frame = CGRectMake(35, 100, 260, 30);16 button.backgroundColor = [UIColor orangeColor];17 [button setTitle:@"确定" forState:UIControlStateNormal];18 [button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];19 [button addTarget:self action:@selector(clickAction:) forControlEvents:UIControlEventTouchUpInside];20 [self.view addSubview:button];21 }22 23 // 按钮点击方法24 - (void)clickAction:(UIButton *)button {25 MyAlertViewBlock *alertView = [[MyAlertViewBlock alloc]initWithTitle:@"测试"message:@"将UIAlertView的按钮点击事件代理用block实现" cancelButtonTitle:@"取消"otherButtonTitles:@"确定"andTouchBlock:^(NSInteger buttonIndex) {26 //在这里面执行触发的行为，省掉了代理，这样的好处是在使用多个Alert的时候可以明确定义各自触发的行为，不需要在代理方法里判断是哪个Alert了27 if (buttonIndex == 0) {28 NSLog(@"取消");29 } else if (buttonIndex == 1) {30 NSLog(@"确定");31 }32 }];33 34 [alertView show];35 }36 37 @end
其运行效果如下:
