在自定義UITableViewCell內的UIButton中添加UILongPressGestureRecognizer

Question

我有一個帶有各種IBOutlet的自定義單元格，但是我想在一個按鈕上添加一個UILongPressGestureRecognizer以進行長按手勢。 這是我的代碼（btw插座連接正確，按鈕的IBAction方法正確調用）：

MyCustomCell.h

@interface MyCustomCell : UITableViewCell
@property (strong, nonatomic) IBOutlet UIButton *myButton;
@property (strong, nonatomic) UILongPressGestureRecognizer *longPressGestureRecognizer;
@end

MyCustomCell.m

- (void)awakeFromNib
{
    // Initialization code
    self.longPressGestureRecognizer = nil;
}

MyViewController.m

#import MyCustomCell.h

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *identifier = @"MyCell";
    MyCustomCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier forIndexPath:indexPath];
    if (!cell){
        cell = [[MyCustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier];
    }

    cell.longPressGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPressGestures:)];
    cell.longPressGestureRecognizer.minimumPressDuration = 1.0f;
    cell.longPressGestureRecognizer.allowableMovement = 300.0f;
    [cell.myButton addGestureRecognizer:cell.longPressGestureRecognizer];
}

- (void)handleLongPressGestures:(UIGestureRecognizer *)recognizer
{
    if ([recognizer.view isKindOfClass:[UIButton class]]){
        if (recognizer.state == UIGestureRecognizerStateBegan){
            NSLog(@"Long press began");
        } else if (recognizer.state = UIGestureRecognizerStateEnded){
            NSLog(@"Long press ended");
        }
    }
}

問題是handleLongPressGestures:永遠不會調用方法。

Answer 1

longPressGestureRecognizer應該是控制器上的屬性，而不是視圖（MyCustomCell）。 將屬性移到MyViewController，然后重試。 我的猜測是，它在MyCustomCell排隊和出隊時發生了奇怪的事情。

要重用的對象（單元）應輕巧。 在這種情況下，longPressGestureRecognizer的目標是視圖控制器，並且很討厭。

Answer 2

嘗試這個！

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UILongPressGestureRecognizer *LongPress=[[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(handleLongPressGestures:)];
    LongPress.minimumPressDuration = 1.0f;
    LongPress.allowableMovement = 300.0f;
    [cell.myButton addGestureRecognizer:LongPress];
}

- (void)handleLongPressGestures:(UIGestureRecognizer *)recognizer
{
      if ([recognizer.view isKindOfClass:[UIButton class]]){
         if (recognizer.state == UIGestureRecognizerStateBegan){
             NSLog(@"Long press began");
         } 
         else if (recognizer.state = UIGestureRecognizerStateEnded)
         {
             NSLog(@"Long press ended");
         }
      }
 }

Answer 3

嘗試這種方式

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *identifier = @"MyCell";
    MyCustomCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier forIndexPath:indexPath];
    if (!cell){
        cell = [[MyCustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier];
    }
    if ([[cell gestureRecognizers] count]<1) {
        UILongPressGestureRecognizer *longPressGestureRecognizer;
        longPressGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPressGestures:)];
        longPressGestureRecognizer.minimumPressDuration = 1.0f;
        longPressGestureRecognizer.allowableMovement = 300.0f;
        longPressGestureRecognizer.delegate = self;
        [cell.myButton addGestureRecognizer:cell.longPressGestureRecognizer];
    }
}

這種類型的代碼對我有用。