弹窗

- (IBAction)doClick:(UIButton *)sender {
    
    
    UIAlertController * alertC = [UIAlertController alertControllerWithTitle:@"随便按" message:@"让你按你就按" preferredStyle:UIAlertControllerStyleActionSheet];
    
    UIAlertAction * action1 = [UIAlertAction actionWithTitle:@"选项1" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        NSLog(@"click001");
    }];
    [alertC addAction:action1];
    
    UIAlertAction * action2 = [UIAlertAction actionWithTitle:@"选项2" style:(UIAlertActionStyleDefault) handler:^(UIAlertAction * _Nonnull action) {
        NSLog(@"click002");
    }];
    [alertC addAction:action2];
    
    UIAlertAction * action3 = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
        NSLog(@"取消");
    }];
    [alertC addAction:action3];
    
    [self presentViewController:alertC animated:YES completion:nil];
    
}

• 该方法于iOS8推出，并代替UIAlertView和UIActionSheet两种方法，分别用创建时的preferredStyle来代表前两种方法：UIAlertControllerStyleActionAlert、UIAlertControllerStyleActionSheet。
• 对应选项的响应分别在UIAlertAction的block内部实现。