的Xcode UITouch和UIImage的用戶觸摸置入圖像，其中觸摸

Question

Xcode的地方，用戶觸摸

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{ 
UITouch *touch=[[event allTouches]anyObject]; 
CGPoint point= [touch locationInView:touch.view]; 

UIImage *image = [[UIImage alloc]initWithContentsOfFile:@"BluePin.png"]; 
[image drawAtPoint:point]; 
} 

基本上觸摸屏圖像應該出現在那裏感動，但似乎沒有一個圖片...

Answer 1

1. 你應該像這樣初始化UIImage：

   UIImage *image = [UIImage imageNamed:@"BluePin"]; 
   

2. 您應該使用UIImageVie如果要包含UIImage，則不能直接將UIImage放入UIView。

更新

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{ 
    UITouch *touch=[[event allTouches]anyObject]; 
    CGPoint point= [touch locationInView:touch.view]; 

    UIImage *image = [UIImage imageNamed:@"BluePin"]; 
    CGRect rect=CGRectMake(point.x, point.y, image.size.width, image.size.height); 
    UIImageView *imageView=[[UIImageView alloc]initWithFrame:rect]; 
    [imageView setImage:image]; 
    [self.view addSubview:imageView]; 
} 

Answer 2

要添加到其他的答案，這裏是你如何製作動畫：

- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{ 
    NSLog(@"Touches began!"); 
    UITouch *touch= [[event allTouches] anyObject]; 
    CGPoint point= [touch locationInView:touch.view]; 

    UIImage *image = [UIImage imageNamed:@"BluePin.png"]; 

    UIImageView *imageView = [[UIImageView alloc] initWithImage:image]; 
    [imageView setFrame: CGRectMake(point.x-(imageView.bounds.size.width/2), point.y-(imageView.bounds.size.width/2), imageView.bounds.size.width, imageView.bounds.size.height)]; 
    [self addSubview: imageView]; 
    //self.currentPins += 1; 

    [UIView animateWithDuration:2.0 delay:1.0 options:UIViewAnimationOptionCurveLinear animations:^{ 
     [imageView setAlpha:0.0]; 
    } completion:^(BOOL finished) { 
     [imageView removeFromSuperview]; 
     //self.currentPins -= 1; 
    }]; 

    // for(;self.currentPins > 10; currentPins -= 1){ 
    //  [[[self subviews] objectAtIndex:0] removeFromSuperview]; 
    // } 
} 

註釋掉的代碼是一點點額外的我寫的假設您擁有一個名爲的@property currentPins，一次將屏幕上的引腳數量限制爲10。經過測試，它的工作原理，假設我在複製，粘貼和評論幾行後沒有搞亂任何東西。

編輯：無視註釋掉的代碼。我實際上混合了兩個版本（一個沒有動畫，一個），所以它被打破了。