如何檢測哪個UILabel被竊聽？

Question

我有三個UILabels。 我想檢測哪個標簽是Tapped，然后檢索該標簽的字符串值 。 這就是我的嘗試，我只能設法檢測輕敲的位置，但我無法檢測到哪個標簽被點擊。

標簽創建

for (NSInteger i=1; i<=[pdfs count]; i++){
    UILabel *newLabel=[[UILabel alloc] init];
    newLabel.text = [NSString stringWithFormat:[[pdfs objectAtIndex:(i-1)] lastPathComponent]];
    newLabel.frame = CGRectMake(10, 60*i, 320, 20);
    newLabel.tag=i;
    newLabel.font = [UIFont systemFontOfSize:20.0f];
    newLabel.backgroundColor = [UIColor clearColor];
    newLabel.userInteractionEnabled = YES;
    [self.view addSubview:newLabel];
    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
    [newLabel addGestureRecognizer:singleTap]; 
    [newLabel release], newLabel=nil;
    [singleTap release];
} 

檢測水龍頭

 - (void)handleSingleTap:(UITapGestureRecognizer *)recognizer

{

CGPoint location;
location = [recognizer locationInView:self.view];

NSString *documentName;
if(location.y<150.0){
    documentName = [[pdfs objectAtIndex:0] lastPathComponent]; 
}
else{
    documentName = [[pdfs objectAtIndex:1] lastPathComponent]; 
}

Answer 1

UIGestureRecognizer引用了它所附加的視圖，因此您可以從中獲取標簽的標簽：

int touchedtag = recognizer.view.tag;
documentName = [[pdfs objectAtIndex:touchedtag-1] lastPathComponent]; 

Answer 2

手勢識別器知道它屬於哪個視圖。

UIView *theView = recognizer.view;
// cast it to UILabel if you are sure it is one
UILabel *theLabel = (UILabel *)theView;

Answer 3

正如您在標簽上添加GestureRecognizer

 // called when touch is began or when user touches 
    - (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
    {
          UITouch *touch = [touches anyObject]; 

          UILabel *theLabel = (UILabel *)touch.view;

          if (theLabel.tag == 1)
          {}
          else if ...
    }

Answer 4

為什么要將標簽用作按鈕？ 只需使用按鈕，就可以將它們配置為看起來就像標簽一樣。