在UICollectionView复制标注(Copy Callout in UICollection

我有一个的UIImageView在UICollectionView每个小区，现在我想添加复制标注，就像在Photos.app：

我看到UICollectionViewDelegate这个方法：

- (BOOL)collectionView:(UICollectionView *)collectionView shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath {
    return YES;
}

研究一些额外的几分钟后，我发现UIMenuController类，因为我明白，我必须同它合作，以获得菜单，但无论如何，我认为必须有更简单的方法，然后创建UIGestureRecognizer，以及创建，定位等我UIMenu。

我在正确的轨道上？ 你怎么能实现这个功能？

Answer 1:

是的，你是在正确的轨道上。您也可以实现超越剪切，复制自定义操作，使用这种技术贴。

对于UICollectionView自定义操作

// ViewController.h
@interface ViewController : UICollectionViewController

// ViewController.m
-(void)viewDidLoad
{
    [super viewDidLoad];
    self.collectionView.delegate = self;

    UIMenuItem *menuItem = [[UIMenuItem alloc] initWithTitle:@"Custom Action"
                                                      action:@selector(customAction:)];
    [[UIMenuController sharedMenuController] setMenuItems:[NSArray arrayWithObject:menuItem]];

}

#pragma mark - UICollectionViewDelegate methods
- (BOOL)collectionView:(UICollectionView *)collectionView
      canPerformAction:(SEL)action
    forItemAtIndexPath:(NSIndexPath *)indexPath
            withSender:(id)sender {
    return YES;  // YES for the Cut, copy, paste actions
}

- (BOOL)collectionView:(UICollectionView *)collectionView
shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath {
    return YES;
}

- (void)collectionView:(UICollectionView *)collectionView
         performAction:(SEL)action
    forItemAtIndexPath:(NSIndexPath *)indexPath
            withSender:(id)sender {
    NSLog(@"performAction");
}

#pragma mark - UIMenuController required methods
- (BOOL)canBecomeFirstResponder {
    // NOTE: The menu item will on iOS 6.0 without YES (May be optional on iOS 7.0)
    return YES;
}

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
    NSLog(@"canPerformAction");
     // The selector(s) should match your UIMenuItem selector
    if (action == @selector(customAction:)) {
        return YES;
    }
    return NO;
}

#pragma mark - Custom Action(s)
- (void)customAction:(id)sender {
    NSLog(@"custom action! %@", sender);
}

注：的iOS 7.0更改行为

在你UICollectionViewCell子类中，你需要添加自定义操作方法，或者什么也不会出现。

 // Cell.m #import "Cell.h" @implementation Cell - (id)initWithFrame:(CGRect)frame { self = [super initWithFrame:frame]; if (self) { // custom logic } return self; } - (void)customAction:(id)sender { NSLog(@"Hello"); if([self.delegate respondsToSelector:@selector(customAction:forCell:)]) { [self.delegate customAction:sender forCell:self]; } } @end

你需要创建一个委托协议，将其放置在每一个细胞都回调到维护您的UICollectionView的UIController。这是因为，细胞不应该对你的模型没有什么，因为它只涉及显示内容。

 // Cell.h #import <UIKit/UIKit.h> @class Cell; // Forward declare Custom Cell for the property @protocol MyMenuDelegate <NSObject> @optional - (void)customAction:(id)sender forCell:(Cell *)cell; @end @interface Cell : UICollectionViewCell @property (strong, nonatomic) UILabel* label; @property (weak, nonatomic) id<MyMenuDelegate> delegate; @end

在你UICollectionViewController的视图控制器或子类，您需要符合协议并实施新的方法。

 // ViewController.m @interface ViewController () <MyMenuDelegate> @end // @implementation ViewController ... - (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath; { Cell *cell = [cv dequeueReusableCellWithReuseIdentifier:@"MY_CELL" forIndexPath:indexPath]; cell.delegate = self; return cell; } // ... // Delegate method for iOS 7.0 to get action from UICollectionViewCell - (void)customAction:(id)sender forCell:(Cell *)cell { NSLog(@"custom action! %@", sender); }

可选：在你的UIView子类可以覆盖默认的剪切，复制，如果你在这里实现的方法canPerformAction，粘贴而不是在UIViewController中。否则，行为将显示您的自定义方法之前默认的方法。

 // Cell.m - (BOOL)canPerformAction:(SEL)action withSender:(id)sender { NSLog(@"canPerformAction"); // The selector(s) should match your UIMenuItem selector NSLog(@"Sender: %@", sender); if (action == @selector(customAction:)) { return YES; } return NO; }

Answer 2:

这是一个完整的解决方案：

- (BOOL)collectionView:(UICollectionView *)collectionView shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath {
        return YES;
    }

- (BOOL)collectionView:(UICollectionView *)collectionView canPerformAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender {
        if ([NSStringFromSelector(action) isEqualToString:@"copy:"])
            return YES;
        else
            return NO;
    }

- (void)collectionView:(UICollectionView *)collectionView performAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender {
        if ([NSStringFromSelector(action) isEqualToString:@"copy:"]) {
            UIPasteboard *pasteBoard = [UIPasteboard pasteboardWithName:UIPasteboardNameGeneral create:NO];
            pasteBoard.persistent = YES;
            NSData *capturedImageData = UIImagePNGRepresentation([_capturedPhotos objectAtIndex:indexPath.row]);
            [pasteBoard setData:capturedImageData forPasteboardType:(NSString *)kUTTypePNG];
        }
    }

就我而言，我只允许在我的CollectionView复印功能，如果按复印，我复制是细胞到剪贴板内的图像。

Answer 3:

也许有点晚了，但我发现也许对于那些谁仍在寻找这更好的解决方案：

在你UICollectionViewController的viewDidLoad中添加项：

UIMenuItem *menuItem = [[UIMenuItem alloc] initWithTitle:@"Title" action:@selector(action:)];
[[UIMenuController sharedMenuController] setMenuItems:[NSArray arrayWithObject:menuItem]];

添加下面的委托方法：

//This method is called instead of canPerformAction for each action (copy, cut and paste too)
- (BOOL)collectionView:(UICollectionView *)collectionView canPerformAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender {
        if (action == @selector(action:)) {
            return YES;
        }
        return NO;
    }
    //Yes for showing menu in general
    - (BOOL)collectionView:(UICollectionView *)collectionView shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath {
        return YES;
    }

子类UICollectionViewCell如果你没有了。添加您为您的项目指定的方法：

- (void)action:(UIMenuController*)menuController {

}

这样，你不需要任何becomeFirstResponder或其他方法。你在一个地方的所有行动，你可以轻松地处理不同的细胞，如果你打电话与细胞本身作为一个参数的一般方法。

编辑：不知何故，uicollectionview需要这种方法的存在（此方法不调用自定义操作，我认为uicollectionview只检查所有脑干）

- (void)collectionView:(UICollectionView *)collectionView performAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender {

}

文章来源: Copy Callout in UICollectionView