Question

我无法理解Event Handling Guide for iOS－Interacting with Other User Interface Controls

中的表达方式

如果您有其中一个控件的自定义子类，并且想要更改＆gt;默认操作，请将手势识别器直接附加到控件而不是＆gt;父视图。然后，手势识别器首先接收触摸事件。

谁能给我一些例子？ THX

Answer 1

UIButton的子类附加手势识别器。

在CustomButton.m

中

#import "CustomButton.h"

@implementation CustomButton

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {

        UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc]
                                              initWithTarget:self action:@selector(handleTap)];
        tapGesture.numberOfTapsRequired = 2;
        [self addGestureRecognizer:tapGesture];
    }
    return self;
}

- (void)handleTap
{
    NSLog(@"Button tapped twice");
}

在ViewController中启动按钮并添加为子视图

#import "ViewController.h"
#import "CustomButton.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    CustomButton *customButton = [[CustomButton alloc] initWithFrame:CGRectMake(100.0f, 100.0f, 150.0f, 100.0f)];
    [customButton setTitle:@"Tap Twice" forState:UIControlStateNormal];
    customButton.backgroundColor = [UIColor grayColor];
    [self.view addSubview:customButton];

}

通常按钮适用于单击。我们通过添加点击手势识别器和点击次数2来更改按钮的默认行为。

通过手势识别器更改UIButton默认操作

1 个答案: