手勢處理

在ios開發中，需用到對于手指的不同操作，以手指點擊為例：分為單指單擊、單指多擊、多指單擊、多指多擊。對于這些事件進行不同的操作處理，由于使用系統自帶的方法通過判斷touches不太容易處理，而且會有事件之間的沖突。

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接下來，通過以UITapGestureRecognizer?手勢實現此功能需求?代碼如下：

ViewController.m中的viewDidLoad方法：

//單指單擊
    UITapGestureRecognizer *singleFingerOne = [[UITapGestureRecognizer alloc] initWithTarget:self
                                    action:@selector(handleSingleFingerEvent:)];
    singleFingerOne.numberOfTouchesRequired = 1; //手指數
    singleFingerOne.numberOfTapsRequired = 1; //tap次數
    singleFingerOne.delegate = self;

    //單指雙擊
    UITapGestureRecognizer *singleFingerTwo = [[UITapGestureRecognizer alloc] initWithTarget:self
                                     action:@selector(handleSingleFingerEvent:)];
    singleFingerTwo.numberOfTouchesRequired = 1;
    singleFingerTwo.numberOfTapsRequired = 2;
    singleFingerTwo.delegate = self;

    //雙指單擊
    UITapGestureRecognizer *doubleFingerOne = [[UITapGestureRecognizer alloc] initWithTarget:self
                                     action:@selector(handleDoubleFingerEvent:)];
    doubleFingerOne.numberOfTouchesRequired = 2;
    doubleFingerOne.numberOfTapsRequired = 1;
    doubleFingerOne.delegate = self;

    UITapGestureRecognizer *doubleFingerTwo = [[UITapGestureRecognizer alloc] initWithTarget:self
?? action:@selector(handleDoubleFingerEvent:)];
    doubleFingerTwo.numberOfTouchesRequired = 2;
    doubleFingerTwo.numberOfTapsRequired = 2;
    doubleFingerTwo.delegate = self;

    //如果不加下面的話，當單指雙擊時，會先調用單指單擊中的處理，再調用單指雙擊中的處理
    [singleFingerOne requireGestureRecognizerToFail:singleFingerTwo];
    //同理雙指亦是如此
    [doubleFingerOne requireGestureRecognizerToFail:doubleFingerTwo];

    [self.view addGestureRecognizer:singleFingerOne];
    [self.view addGestureRecognizer:singleFingerTwo];
    [self.view addGestureRecognizer:doubleFingerOne];
    [self.view addGestureRecognizer:doubleFingerTwo];

    [singleFingerOne release];
    [singleFingerTwo release];
    [doubleFingerOne release];
    [doubleFingerTwo release];

處理事件的方法，代碼：

//處理單指事件
- (void)handleSingleFingerEvent:(UITapGestureRecognizer *)sender
{
    if (sender.numberOfTapsRequired == 1) {
        //單指單擊
        NSLog(@"單指單擊");
    }else if(sender.numberOfTapsRequired == 2){
        //單指雙擊
        NSLog(@"單指雙擊");
    }
}
//處理雙指事件
- (void)handleDoubleFingerEvent:(UITapGestureRecognizer *)sender
{
    if (sender.numberOfTapsRequired == 1) {
        //雙指單擊
        NSLog(@"雙指單擊");
    }else if(sender.numberOfTapsRequired == 2){
        //雙指雙擊
        NSLog(@"雙指雙擊");
    }
}

將相應代碼復制到你的工程中即可使用，由于代碼中已經有詳細的解釋說明，這里就不在重復解釋了。

代碼中只是列舉了單指與雙指對于單擊或多擊的處理，同理多指的操作需修改numberOfTouchesRequired屬性，對點擊的次數需修改numberOfTapsRequired屬性。

對于其他手勢例如UISwipeGestureRecognizer，UILongPressGestureRecognizer,UILongPressGestureRecognizer的操作使用類似處理。