ios - 如何从 NSArray 中选择一个 UIImgeView

Question

我有用作可拖动对象的 UIImageView，它们位于 NSArray 中，所以在拖动它们时它们工作正常，但我想要的是当我拖动时它们并完成拖动方法，而不是将图像放入 UIImageView 我只想在拖动完成时用自定义图像替换它。所以我的问题是，如果我删除 NSArray 并将其设为仅 IF 语句，它可以正常工作但只拍摄一张图像，如果我将其放入 NSArray 中，如下面的代码所示只拍摄最后一张图片 (Close2) 并且不附加它

UIImage+Stuff.h

    #import <UIKit/UIKit.h>

    @interface UIImage (Stuff)

    //
    // return an UIImage from a CALayer
    //
    + ( UIImage* ) grabImage:(CALayer*)layer;

    @end

UIImage+Stuff.m

    #import "UIImage+Stuff.h"

    @implementation UIImage (Stuff)

    + ( UIImage* ) grabImage:(CALayer*)layer
    {
    UIGraphicsBeginImageContext ( layer.frame.size );
    [ layer renderInContext:UIGraphicsGetCurrentContext() ];

        UIImage *grab = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

        return grab;
    }
    @end

主游戏VC.h

    @class APChartObject;

    //
    // drag status
    //
    typedef enum {
    tDragStatusBegin = 0,
    tDragStatusEnd,
    tDragStatusIntersectIn,
    tDragStatusIntersectOut
    } tDragStatus;

    @interface MainGameVC : UIViewController

    @property (nonatomic, strong) IBOutletCollection(UIImageView) NSArray *TopMenuImages;
    //top menu scroll views
    @property (nonatomic, retain) IBOutlet UIScrollView *TopMenuViewer;
    @property (nonatomic, retain) IBOutlet UIScrollView *scrollview;

    //drag and drop
    @property (nonatomic, strong) IBOutlet UIView *DropView;
    @property (nonatomic, strong) UIImageView *dragObject;
    @property (nonatomic, strong) IBOutlet UIScrollView *cart;
    @property (nonatomic, assign) tDragStatus dragging;
    @property (nonatomic, strong) APChartObject *selectedModel;

    // all tools
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectBox;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectSand;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectSoil;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectWater;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectWheat;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectCorn;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectGarlic;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectLettuse;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectOnion;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectSugercane;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectTomato;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectCucumber;
    @property (weak, nonatomic) IBOutlet UIImageView *DragedObjectBeans;
    @end

MainGameVC.m

    #import "UIImage+Stuff.h"
@interface MainGameVC ()
{
    UIImageView *_selectedView;
    CGPoint _startPoint;
    int selectedViewTag;
}

@end

- (void)viewDidLoad
{
    // drag and drop touch
    UIPanGestureRecognizer *DragAndDrop = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panDetected:)];
    [self.TopMenuViewer addGestureRecognizer:DragAndDrop];

    NSArray *imageViewArray = [NSArray arrayWithObjects:DragedObjectWheat,DragedObjectCorn,DragedObjectOnion, nil];

    for(UIImageView *image in imageViewArray)
    {
        UIPanGestureRecognizer *DragAndDrop2 = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panDetected:) ];
        [DragAndDrop2 setMinimumNumberOfTouches:1];

        [image addGestureRecognizer:DragAndDrop2];
        image.userInteractionEnabled = YES;

    }

}

//+---------------------------------------------------------------------------+
#pragma mark - View exchange
// +---------------------------------------------------------------------------+


    //
    // make the tricks.
    // Add a subview with the screenshot of selected and move around the screen
    //
    - ( void) cloneViewWithCenter:(CGPoint)point image:(UIImage*)grab ImageTag:(int)ToolTag
    {
    if ( _selectedView ) [ _selectedView removeFromSuperview ];
    selectedViewTag = ToolTag;
    _selectedView = [[ UIImageView alloc ] initWithImage:grab ];
    _selectedView.frame = CGRectMake(point.x, point.y, grab.size.width,   grab.size.height);
    _selectedView.userInteractionEnabled = YES;

    [ self.view addSubview:_selectedView ];

    UIPanGestureRecognizer *pan = [[ UIPanGestureRecognizer alloc ] initWithTarget:self  action:@selector(moveObject:) ];
    [ pan setMinimumNumberOfTouches:1 ];
    [ _selectedView addGestureRecognizer:pan ];
    }


    // +---------------------------------------------------------------------------+
    #pragma mark - Refresh
    // +---------------------------------------------------------------------------+


    //
    // refresh loop
    //
    - (void) refreshView
    {
    [UIView animateWithDuration:0.2 animations:^
     {
         CGRect r = _selectedView.frame;

         switch ( _dragging ) {
             case tDragStatusBegin:
                 r.size.width  *= 1;
                 r.size.height *= 1;
                 break;
             case tDragStatusEnd:
                 r.size.width  /= 1;
                 r.size.height /= 1;
                 break;
             case tDragStatusIntersectIn:
                 r.size.width  = 1;
                 r.size.height = 1;

                 [ self finishDrag ];
                 break;
             case tDragStatusIntersectOut:
                 _selectedView.center = _startPoint;
                 break;
         }

         _selectedView.frame = r;

     } completion:^(BOOL finished)
     {

         if ( _dragging == tDragStatusIntersectOut )
             _selectedView.hidden = YES;

     }];
    }

    //
    // end drag
    //
    - (void) finishDrag
    {
    UIImageView *Tool;

    UIImage *ReplacedPhoto;
    UIImageView *imageView;
    switch (selectedViewTag)
    {

        case 1:

        {
            logic for image tag 1
                break;
        }
        case 2:

        {
            logic for image tag 2
                break;
        }

            Tool.userInteractionEnabled = YES;
            [self appendView:Tool];
    }

    //
    // check for insertion in cart (or not)
    //
    - (void) checkForIntersection
    {
        //
        // ABS coords.
        //
        CGRect childRect = [ self.view convertRect:_selectedView.frame fromView:nil ];
        CGRect cartRect  = [ self.view convertRect:_cart.frame fromView:nil ];

        if ( CGRectIntersectsRect ( childRect, cartRect ))
        {
            self.dragging = tDragStatusIntersectIn;

        }
        else
        {
            self.dragging = tDragStatusIntersectOut;
        }
    }

    - (void) refreshCart
    {
        [ _cart setContentOffset:CGPointMake(_cart.contentOffset.x, 0) animated:YES ];
    }


    // +---------------------------------------------------------------------------+
    #pragma mark - Pan gesture
    // +---------------------------------------------------------------------------+

    - ( void ) panDetected:(UIPanGestureRecognizer*)gesture
    {

        CGPoint pInView = [ gesture locationInView:self.view ];
        //CGSize  pSize   = gesture.view.frame.size;

        if ( gesture.state == UIGestureRecognizerStateBegan )
        {
            _startPoint = pInView;
            UIImage *grab = [UIImage grabImage: gesture.view.layer];
            ToolTag = gesture.view.tag ;
            for (int i = 0; i>ToolTag; i++)
            {
                i = i+1;
                ToolTag = i;
            }
            //
            // centering view
            //
            //pInView.x = pInView.x - pSize.width/2;
            //pInView.y = pInView.y - pSize.height/2;

            [ self cloneViewWithCenter:pInView image:grab ImageTag:ToolTag ];

            self.dragging = tDragStatusBegin;
        }
        else if ( gesture.state == UIGestureRecognizerStateChanged )
        {
            [ self moveObject:gesture ];
        }
        else if ( gesture.state == UIGestureRecognizerStateEnded )
        {
            self.dragging = tDragStatusEnd;
            [ self checkForIntersection ];
        }
    }

    //
    // move draggable view around
    //
    - (void) moveObject:(UIPanGestureRecognizer *)pan
    {
        _selectedView.center = [ pan locationInView:_selectedView.superview ];
    }


// +---------------------------------------------------------------------------+
#pragma mark - Setter
// +---------------------------------------------------------------------------+


    - (void)setDragging:(tDragStatus)dragging
    {
        _dragging = dragging;
        [ self refreshView ];
    }


    // +---------------------------------------------------------------------------+
#pragma mark - Chart view
    // +---------------------------------------------------------------------------+


    //
    // recursively append view to scrollview.
    // If position already contains a view, shift and retry.
    //
    - (void) appendView:(id)view
    {

        [ _cart addSubview:view ];

        [ self performSelector:@selector(refreshCart) withObject:nil afterDelay:0 ];
    }
    @end

Answer 1

在您的头文件中声明一个属性来保存您的 ImageView ，然后将它们连接到界面构建器中。

@interface YourViewController : UIViewController

@property (nonatomic, strong) IBOutletCollection(UIImageView) NSArray *imageViews;
//...

@end

现在在界面构建器中，您需要将所有 imageView 连接到这个新属性。

现在您需要使用 imageViews 集合。您甚至可以手动标记图像，稍后可用于检查拖动了哪个图像。

for (UIImageView *imageView in self.imageViews) {
  if (imageView.tag == 1){ 
  // .. Logic for image with tag 1
  }
  elseif (imageView.tag == 2){ 
  // .. Logic for image with tag 2
  }
}