拖放的UIButton从UIScrollView的UIView的到在目标C(Drag & Drop

我想补充拖放的拖放功能UIButton 。其实我已经编程方式下创建按钮的数量UIScrollView 。我想补充的目标之后UIButton

[mybutton addTarget:self action:@selector(wasDragged:withEvent:)forControlEvents:UIControlEventTouchDragInside];

这是该方法

- (void)wasDragged:(UIButton *)button withEvent:(UIEvent *)event
 {
// get the touch

UIButton *myButton=[[UIButton alloc]init];
myButton=button;
[self.scrollView addSubview:myButton];

UITouch *touch = [[event touchesForView:button] anyObject];

//get delta
CGPoint previousLocation = [touch previousLocationInView:myButton];
CGPoint location = [touch locationInView:myButton];
CGFloat delta_x = location.x - previousLocation.x;
CGFloat delta_y = location.y - previousLocation.y;

//move button
myButton.center = CGPointMake(myButton.center.x + delta_x,myButton.center.y + delta_y);

}

该代码被滚动视图下工作正常和按钮拖放滚动视图的内部。现在的问题是，当我拖动滚动视图外的按钮，按钮消失。我想滚动视图外拖动按钮也。我怎样才能做到这一点？我怎样才能拖动按钮从滚动型到另一个的UIView？这怎么可能？

Answer 1:

ViewController.h

@interface ViewController : UIViewController <UIScrollViewDelegate>{
}

@property (nonatomic, strong) IBOutlet UIView *dropTarget;
@property (nonatomic, strong) UIImageView *dragObject;
@property (nonatomic, retain) UITextView *txt_View;
@property (nonatomic, strong) UIImageView *prevdragObject;
@property (nonatomic, assign) CGPoint touchOffset;
@property (nonatomic, assign) CGPoint homePosition;
@end

只是代替

 IBOutlet UIView *dropTarget

只是使用

IBOutlet UIScrollView *dropTarget

ViewController.m

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
       if ([touches count] == 1) {
        // one finger
        CGPoint touchPoint = [[touches anyObject] locationInView:self.view];
        for (UIImageView *iView in self.view.subviews) {
            if ([iView isMemberOfClass:[UIImageView class]]) {
                if (touchPoint.x > iView.frame.origin.x &&
                    touchPoint.x < iView.frame.origin.x + iView.frame.size.width &&
                    touchPoint.y > iView.frame.origin.y &&
                    touchPoint.y < iView.frame.origin.y + iView.frame.size.height)
                {
                    self.dragObject = iView;
                    self.touchOffset = CGPointMake(touchPoint.x - iView.frame.origin.x,
                                                   touchPoint.y - iView.frame.origin.y);
                    self.homePosition = CGPointMake(iView.frame.origin.x,
                                                    iView.frame.origin.y);
                    [self.view bringSubviewToFront:self.dragObject];
                }
            }
        }
    }
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
   CGPoint touchPoint = [[touches anyObject] locationInView:self.view];
   CGRect newDragObjectFrame = CGRectMake(touchPoint.x - touchOffset.x,
                                       touchPoint.y - touchOffset.y,
                                       self.dragObject.frame.size.width,
                                       self.dragObject.frame.size.height);
   self.dragObject.frame = newDragObjectFrame;
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    CGPoint touchPoint = [[touches anyObject] locationInView:self.view];
    if (touchPoint.x > self.dropTarget.frame.origin.x &&
    touchPoint.x < self.dropTarget.frame.origin.x + self.dropTarget.frame.size.width &&
    touchPoint.y > self.dropTarget.frame.origin.y &&
    touchPoint.y < self.dropTarget.frame.origin.y + self.dropTarget.frame.size.height )
    {
        self.dropTarget.backgroundColor = [UIColor colorWithPatternImage:self.dragObject.image];
    }
    self.dragObject.frame = CGRectMake(self.homePosition.x, self.homePosition.y, self.dragObject.frame.size.width, self.dragObject.frame.size.height);
    self.prevdragObject.frame = self.dragObject.frame;
}