UILongPressGestureRecognizer將不會響應觸摸和鎖定

Question

我正在爲iPhone編寫Objective-C程序。

我想實現一個UILongPressGestureRecognizer，並不能讓它按照我想要的方式工作。

我想做的是簡單的：

響應觸摸是舉行下在屏幕上。

UILongPressGestureRecognizer工作得很好，只要觸摸移動，觸摸開始，但如果我在同一個地方按住觸摸，什麼都不會發生。

爲什麼？

我該如何處理開始，不移動，並保持在同一個地方？

這是我目前的代碼。

---

// Configure the press and hold gesture recognizer 
touchAndHoldRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(touchAndHold:)]; 
touchAndHoldRecognizer.minimumPressDuration = 0.1; 
touchAndHoldRecognizer.allowableMovement = 600; 
[self.view addGestureRecognizer:touchAndHoldRecognizer]; 

Answer 1

您所描述的行爲，你的手勢識別沒有收到，當你不動你的處理器還呼籲是標準的行爲。這些手勢的state屬性在移動時屬於UIGestureRecognizerStateChanged類型，所以如果事情沒有改變，您的處理程序將不會被調用。

你可以

• 在調用與UIGestureRecognizerStateBegan開始重複的計時器state你的手勢識別;
• 打電話給您的手勢識別器stateUIGestureRecognizerStateCancelled,UIGestureRecognizerStateFailed或UIGestureRecognizerStateEnded然後invalidate並釋放計時器;
• 確保手勢識別方法是節約的任何值，你正在尋找一些類屬性（的locationInView例如值或其他）

所以，也許是這樣的：

@interface ViewController() 

@property (nonatomic) CGPoint location; 
@property (nonatomic, strong) NSTimer *timer; 

@end 

@implementation ViewController 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    UILongPressGestureRecognizer *gesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleGesture:)]; 
    gesture.minimumPressDuration = 0.1; 
    gesture.allowableMovement = 600; 
    [self.view addGestureRecognizer:gesture]; 
} 

- (void)handleTimer:(NSTimer *)timer 
{ 
    [self someMethod:self.location]; 
} 

- (void)handleGesture:(UIGestureRecognizer *)gesture 
{ 
    self.location = [gesture locationInView:self.view]; 

    if (gesture.state == UIGestureRecognizerStateBegan) 
    { 
     self.timer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(handleTimer:) userInfo:nil repeats:YES]; 
    } 
    else if (gesture.state == UIGestureRecognizerStateCancelled || 
      gesture.state == UIGestureRecognizerStateFailed || 
      gesture.state == UIGestureRecognizerStateEnded) 
    { 
     [self.timer invalidate]; 
     self.timer = nil; 
    } 

    [self someMethod:self.location]; 
} 

- (void)someMethod:(CGPoint)location 
{ 
    // move whatever you wanted to do in the gesture handler here. 

    NSLog(@"%s", __FUNCTION__); 
} 

@end