[英]detect a touch down event on UIImageView(s)
我在UIView上放置了4個UIImageView,並將它命名為
UIImageView myImg1 = [[UIImageView alloc] init];
UIImageView myImg2 = [[UIImageView alloc] init];
UIImageView myImg3 = [[UIImageView alloc] init];
UIImageView myImg4 = [[UIImageView alloc] init];
我怎么能告訴編譯器我剛剛觸及UIImageView 1或UIImaveView 2.如果我只能使用UIImageView來完成這個任務,而不是按鈕。 請指導我這個問題。 謝謝
一個時尚的解決方案是使用UIGestureRecognizer對象:
在你的loadView方法中(或你編寫UIImageView (s)繪圖的任何地方......):
UITapGestureRecognizer *tapRecognizer;
UIImageView *anImageView = [[UIImageView alloc] initWithFrame:CGRectMake(20, 20, 100, 100)];
[anImageView setTag:0]; //Pay attention here!, Tag is used to distinguish between your UIImageView on the selector
[anImageView setBackgroundColor:[UIColor redColor]];
[anImageView setUserInteractionEnabled:TRUE];
tapRecognizer = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageViewDidTapped:)] autorelease];
tapRecognizer.numberOfTapsRequired = 1;
[anImageView addGestureRecognizer:tapRecognizer];
[contentView addSubview:anImageView];
[anImageView release];
UIImageView *anotherImageView = [[UIImageView alloc] initWithFrame:CGRectMake(80, 180, 100, 100)];
[anotherImageView setTag:1]; //Pay attention here!, Tag is used to distinguish between your UIImageView on the selector
[anotherImageView setBackgroundColor:[UIColor greenColor]];
[anotherImageView setUserInteractionEnabled:TRUE];
tapRecognizer = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageViewDidTapped:)] autorelease];
tapRecognizer.numberOfTapsRequired = 1;
[anotherImageView addGestureRecognizer:tapRecognizer];
[contentView addSubview:anotherImageView];
[anotherImageView release];
這是一個簡單的imageViewDidTapped: sample方法,可用於區分上面的兩個示例UIImageView對象:
- (void)imageViewDidTapped:(UIGestureRecognizer *)aGesture {
UITapGestureRecognizer *tapGesture = (UITapGestureRecognizer *)aGesture;
UIImageView *tappedImageView = (UIImageView *)[tapGesture view];
switch (tappedImageView.tag) {
case 0:
NSLog(@"UIImageView 1 was tapped");
break;
case 1:
NSLog(@"UIImageView 2 was tapped");
break;
default:
break;
}
}
您應該考慮使用tag
屬性。 為每個圖像指定一個唯一tag
,然后使用此信息確定觸摸的圖像。 例如,設置標簽
UIImageView myImg1 = [[UIImageView alloc] init];
myImg1.tag = 1;
當你收到img
的觸摸時,請致電
img.tag
檢索標簽。
UITapGestureRecognizer *singleFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
singleFingerTap.numberOfTapsRequired = 1;
[myImg1 addGestureRecognizer:singleFingerTap];
[myImg2 addGestureRecognizer:singleFingerTap];
[singleFingerTap release];
和行動方法
-(void)handleSingleTap:(UIGestureRecognizer*)sender{
//your code here
}
你可以這樣做。
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint touchLocation = [touch locationInView:self.view];
if(CGRectContainsPoint(myImg1.view.frame,touchLocation))
{
NSLog(@" Image 1");
}
else if(CGRectCont..
注意......如果點位於多個圖像視圖中,則會輸出NSLog ..在這種情況下..檢查哪個圖像視圖位於頂部..
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