我有一个视图控制器，其中有一个默认的UIview放置整个屏幕。在这个视图中，我添加了几个UIImageView（比如20左右）。我想支持在这些UIImageView之间交换图像。我已经使用UITapGestureRecogniser来处理在这些UIImageView上发生的触摸事件。我可以在这个UITapGestureRecogniser事件本身下处理这些UIImageView之间的图像拖放吗？ （或）我是否需要使用UIPanGestureRecognizer或触摸事件？在这些UIImageView之间实现拖放图像的最简单和最简单的方法是什么？请建议？iOS：在UIImageView之间移动图像
谢谢！
一些想法。
你可以做到这一点用自来水手势（例如先点击图片查看，点击目标图像视图），但它不是很直观。对UIPanGestureRecognizer进行适当的拖放操作对于最终用户来说会更加直观。
从技术上说，你不是从图像视图拖动图像，而是实际上是拖动图像视图本身。 （一个图像本身没有图像视图，没有可视化表示。）当你放开时，你将动画改变图像视图帧来完成幻觉。
如果你有的imageViews一个NSArray的，你可以手势添加到他们的上海华：
@property (nonatomic, strong) NSMutableArray *imageViews;
- (void)viewDidLoad
{
[super viewDidLoad];
[self createImageViewArray];
UIPanGestureRecognizer *gesture = [[UIPanGestureRecognizer alloc] initWithTarget:self
action:@selector(handlePan:)];
[self.view addGestureRecognizer:gesture];
}
- (void)createImageViewArray
{
self.imageViews = [NSMutableArray array];
// add your imageviews to the array any way you want
...
}
- (void)handlePan:(UIPanGestureRecognizer *)gesture
{
static UIImageView *draggedImage = nil;
static CGRect draggedImageOriginalFrame;
CGPoint location = [gesture locationInView:gesture.view];
if (gesture.state == UIGestureRecognizerStateBegan)
{
// see if we grabbed an imageview
draggedImage = [self determineImageForLocation:location];
// if so, save its old location for future reference and bring it to the front
if (draggedImage)
{
draggedImageOriginalFrame = draggedImage.frame;
[draggedImage.superview bringSubviewToFront:draggedImage];
}
}
else if (gesture.state == UIGestureRecognizerStateChanged && draggedImage != nil)
{
// if we're dragging it, then update its location
CGPoint translation = [gesture translationInView:gesture.view];
CGRect frame = draggedImageOriginalFrame;
frame.origin.x += translation.x;
frame.origin.y += translation.y;
draggedImage.frame = frame;
}
else if (draggedImage != nil && (gesture.state == UIGestureRecognizerStateEnded ||
gesture.state == UIGestureRecognizerStateCancelled ||
gesture.state == UIGestureRecognizerStateFailed))
{
// if we let go, let's see if we dropped it over another image view
UIImageView *droppedOver = nil;
if (gesture.state == UIGestureRecognizerStateEnded)
droppedOver = [self draggedImageView:draggedImage toLocation:location];
if (droppedOver == nil)
{
// fail; animate the restoring of the view back to it's original position
[UIView animateWithDuration:0.25
animations:^{
draggedImage.frame = draggedImageOriginalFrame;
}];
}
else
{
// succeed; make sure to bring the view we're about to animate to the front
[droppedOver.superview bringSubviewToFront:droppedOver];
// animate the swapping of the views
[UIView animateWithDuration:0.25
animations:^{
draggedImage.frame = droppedOver.frame;
droppedOver.frame = draggedImageOriginalFrame;
}];
}
}
}
// see if we dragged an imageview over one of our imageviews, returning a point
// to the image view we dropped it over
- (UIImageView *)draggedImageView:(UIImageView *)draggedView toLocation:(CGPoint)location
{
for (UIImageView *imageview in self.imageViews)
if (CGRectContainsPoint(imageview.frame, location) && imageview != draggedView)
return imageview;
return nil;
}
// see if we started the gesture over an imageview
// (turns out that this is the same as "did we drag an image over another",
// but as we're not dragging an image yet, just pass nil)
- (UIImageView *)determineImageForLocation:(CGPoint)location
{
return [self draggedImageView:nil toLocation:location];
}
不要使用自来水的手势在所有的事实。
秘诀就是使用imageView的superview。
您需要3图像视图的....
UIImageView *ImageViewA
UIImageView *ImageViewB
UIImageView *DraggableImageView
假设你点击屏幕和主机观点得到了的touchesBegan事件......如果你把ImageViewA并测试它的矩形与下面的方法：
[rect containsPoint:touchPoint];
如果这是真的，你已经成功地触动了第一ImageView的...开始在touchesMoved的拖动操作像如下：
如果你拿ImageViewA.superview你会得到视图的主视图...主视图应该再收到以下命令：
[newDraggableImageView setFrame:ImageViewA.frame];
[newDraggableImageView setImage:ImageViewA.image];
[hostView addSubview:newDraggableImageView];
现在你跟踪与UIResponder方法touchesBegain touchesMoved主视图触摸事件和touchesEnded
当你经历touchesMoved：将运动的坐标发送到newDraggableImageView的框架中...
因为它正在拖动...一项所述的方法touchesEnded：
如果图像的帧为第二拖动点的框内然后可以设置最终图像视图
if ([frame containsRect:anotherFrame])
ImageViewB.image = draggableImageView.image;
对不起这是伪代码...希望你了解逻辑流程...将图像添加到主机视图...或应用程序的窗口视图并移动它...一旦移动结束..测试imageView的位置并适当设置新的图像视图。 ..
GOODLUCK！和快乐编码！
Rob的回答非常好。我稍微修改了他的handlePan方法以允许热插拔图像。
- (void)handlePan:(UIPanGestureRecognizer *)gesture
{
static UIImageView *draggedImage = nil;
static CGRect draggedImageLastFrame;
CGPoint location = [gesture locationInView:gesture.view];
if (gesture.state == UIGestureRecognizerStateBegan) {
// see if we grabbed an imageview
draggedImage = [self determineImageForLocation:location];
// if so, save its old location for future reference and bring it to the front
if (draggedImage) {
draggedImageLastFrame = draggedImage.frame;
[draggedImage.superview bringSubviewToFront:draggedImage];
draggedImage.alpha = 0.6f;
}
} else if (gesture.state == UIGestureRecognizerStateChanged && draggedImage != nil) {
// if we're dragging it, then update its horizontal location
CGPoint translation = [gesture translationInView:gesture.view];
CGRect frame = draggedImage.frame;
frame.origin.x += translation.x;
draggedImage.frame = frame;
[gesture setTranslation:CGPointZero inView:gesture.view];
UIImageView *draggedOver = [self draggedImageView:draggedImage toLocation:location];
if (draggedOver != nil) {
// animate the draggedOver image to the the draggedImage's last location
[UIView animateWithDuration:0.25
animations:^{
CGRect currentFrame = draggedOver.frame;
draggedOver.frame = draggedImageLastFrame;
draggedImageLastFrame = currentFrame;
}];
}
} else if (draggedImage != nil && (gesture.state == UIGestureRecognizerStateEnded ||
gesture.state == UIGestureRecognizerStateCancelled ||
gesture.state == UIGestureRecognizerStateFailed)) {
// finished, animate the draggedImage into place
[UIView animateWithDuration:0.25
animations:^{
draggedImage.frame = draggedImageLastFrame;
draggedImage.alpha = 1.0f;
}];
}
}
好，知道了！谢谢。我还有一个疑问是，在这种情况下，如何将两个图像视图移动（交换）到指定的交换位置。 – Getsy 2013-02-19 20:25:29
@Getsy查看示例代码。请注意，如果您在“NSArray”中获得图像视图，则这类内容总是会简化，因此您可以通过它们快速枚举。 – Rob 2013-02-19 21:19:46