添加一个image到imageview,然后拖动image.

方法一:

1.添加image到imageview
 NSString *strings = [NSString stringWithString: @"http://www.google.com.hk/intl/zh-CN/images/logo_cn.png"];
    NSData *date = [[NSData alloc] initWithContentsOfURL: [NSURL URLWithString: strings]];
    
    imageView = [[UIImageView alloc] initWithImage: [UIImage imageWithData: date]];
    imageView.frame = CGRectMake(0, 0, 100, 40);
    imageView.userInteractionEnabled = YES;
    
    [self.view addSubview: imageView];
2.实现UIResponder的两个方法:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
    
    if ([touch view] == imageView)  
    { 
        gestureStartPoint=[touch locationInView: imageView];
       
     }        
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    
    
    UITouch *touch = [touches anyObject];  
    if ([touch view] == imageView)  
    {
        
        CGPoint curr_point=[touch locationInView: imageView];
        
        CGPoint imageCenter = imageView.center;
        
        imageCenter.x += curr_point.x - gestureStartPoint.x;
        imageCenter.y += curr_point.y - gestureStartPoint.y;
        
        imageView.center = imageCenter;
        
    }      
      
}
//CGPoint gestureStartPoint;//手势开始时起点

方法二:

1.添加image的方法同上
2.实现UIResponder方法:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView: self.view];
_isCatSelected = CGRectContainsPoint(_catImageView.frame, currentPoint);
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    
    CGPoint currentPoint = [touch locationInView: self.view];
    CGPoint previousPoint = [touch previousLocationInView: self.view];
if (_isCatSelected) 
    {
        //_catImageView.center = currentPoint;
        
        CGPoint imageCenter = _catImageView.center;
        imageCenter.x += currentPoint.x - previousPoint.x;
        imageCenter.y += currentPoint.y - previousPoint.y;
        
        _catImageView.center = imageCenter;
        
    }
}
//BOOL         _isCatSelected;

附加:

移动image的这样的操作还有如下功能:
到达某个点儿后,就消失,类似于"摘西瓜"操作,代码如下:
在touchesMoved加入以下代码就好了.
if ( imageView.center.y > 300 )
    {
        CGPoint a = CGPointMake(100, 400);
        imageView.center = a;
        
        imageView.hidden = YES;
    }