我有一個視圖控制器，其中有一個默認的UIview放置整個屏幕。在這個視圖中，我添加了幾個UIImageView（比如20左右）。我想支持在這些UIImageView之間交換圖像。我已經使用UITapGestureRecogniser來處理在這些UIImageView上發生的觸摸事件。我可以在這個UITapGestureRecogniser事件本身下處理這些UIImageView之間的圖像拖放嗎？ （或）我是否需要使用UIPanGestureRecognizer或觸摸事件？在這些UIImageView之間實現拖放圖像的最簡單和最簡單的方法是什麼？請建議？iOS：在UIImageView之間移動圖像
謝謝！
一些想法。
你可以做到這一點用自來水手勢（例如先點擊圖片查看，點擊目標圖像視圖），但它不是很直觀。對UIPanGestureRecognizer進行適當的拖放操作對於最終用戶來說會更加直觀。
從技術上說，你不是從圖像視圖拖動圖像，而是實際上是拖動圖像視圖本身。 （一個圖像本身沒有圖像視圖，沒有可視化表示。）當你放開時，你將動畫改變圖像視圖幀來完成幻覺。
如果你有的imageViews一個NSArray的，你可以手勢添加到他們的上海華：
@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];
}
不要使用自來水的手勢在所有的事實。
祕訣就是使用imageView的superview。
您需要3圖像視圖的....
UIImageView *ImageViewA
UIImageView *ImageViewB
UIImageView *DraggableImageView
假設你點擊屏幕和主機觀點得到了的touchesBegan事件......如果你把ImageViewA並測試它的矩形與下面的方法：
[rect containsPoint:touchPoint];
如果這是真的，你已經成功地觸動了第一ImageView的...開始在touchesMoved的拖動操作像如下：
如果你拿ImageViewA.superview你會得到視圖的主視圖...主視圖應該再收到以下命令：
[newDraggableImageView setFrame:ImageViewA.frame];
[newDraggableImageView setImage:ImageViewA.image];
[hostView addSubview:newDraggableImageView];
現在你跟蹤與UIResponder方法touchesBegain touchesMoved主視圖觸摸事件和touchesEnded
當你經歷touchesMoved：將運動的座標發送到newDraggableImageView的框架中...
因爲它正在拖動...一項所述的方法touchesEnded：
如果圖像的幀爲第二拖動點的框內然後可以設置最終圖像視圖
if ([frame containsRect:anotherFrame])
ImageViewB.image = draggableImageView.image;
對不起這是僞代碼...希望你瞭解邏輯流程...將圖像添加到主機視圖...或應用程序的窗口視圖並移動它...一旦移動結束..測試imageView的位置並適當設置新的圖像視圖。 ..
GOODLUCK！和快樂編碼！
Rob的回答非常好。我稍微修改了他的handlePan方法以允許熱插拔圖像。
- (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！謝謝。我還有一個疑問是，在這種情況下，如何將兩個圖像視圖移動（交換）到指定的交換位置。 – Getsy 2013-02-19 20:25:29
@Getsy查看示例代碼。請注意，如果您在「NSArray」中獲得圖像視圖，則這類內容總是會簡化，因此您可以通過它們快速枚舉。 – Rob 2013-02-19 21:19:46