objective-c - UIMenuController sharedMenuController - uicollectionview 的自定义菜单项不显示在 ios 7 中

Question

我正在使用 UIMenuItem 在 UICollectionView 单元格长按中执行自定义操作。这与 iOS 6 完美配合，但现在我将我的应用程序转换为 iOS 7 和 Xcode 5，但它不起作用。自定义项未显示。

UIMenuItem *menuItem = [[UIMenuItem alloc] initWithTitle:@"Unfavorite"
                                                  action:@selector(unFavorite:)];
[[UIMenuController sharedMenuController] setMenuItems:[NSArray arrayWithObject:menuItem]];
[UIMenuController sharedMenuController].menuVisible = YES;

- (BOOL)collectionView:(UICollectionView *)collectionView canPerformAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender;
{
    //do not show default itens like copy, paste....
    [self becomeFirstResponder];
    return NO;
}


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

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

}

 - (BOOL)collectionView:(UICollectionView *)collectionView
 shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath {

    myIndexPath = indexPath;
    return YES;
}

Answer 1

我不知道 iOS 6，但在 iOS 7 中它非常简单。您只需要三个标准的 Collection View 委托(delegate)菜单处理方法，以及单元格子类中的一个操作方法。没有必要玩第一响应者或类似的东西。因此，例如(在此示例中，Copy 是标准项，但 Capital 是我添加到菜单中的内容):

// collection view delegate:

- (BOOL)collectionView:(UICollectionView *)collectionView 
        shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath {
    UIMenuItem* mi = [[UIMenuItem alloc] initWithTitle:@"Capital" 
                      action:NSSelectorFromString(@"capital:")];
    [[UIMenuController sharedMenuController] setMenuItems:@[mi]];
    return YES;
}

- (BOOL)collectionView:(UICollectionView *)collectionView 
        canPerformAction:(SEL)action 
        forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender {
    return (action == NSSelectorFromString(@"copy:") || 
            action == NSSelectorFromString(@"capital:"));
}

- (void)collectionView:(UICollectionView *)collectionView 
        performAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath 
        withSender:(id)sender {
    // in real life, would do something here
    NSString* state = (self.sectionData)[indexPath.section][indexPath.row];
    if (action == NSSelectorFromString(@"copy:"))
        NSLog(@"copying %@", state);
    else if (action == NSSelectorFromString(@"capital:"))
        NSLog(@"fetching the capital of %@", state);
}

// cell subclass:

-(void)capital:(id)sender {
    // find my collection view
    UIView* v = self;
    do {
        v = v.superview;
    } while (![v isKindOfClass:[UICollectionView class]]);
    UICollectionView* cv = (UICollectionView*) v;
    // ask it what index path we are
    NSIndexPath* ip = [cv indexPathForCell:self];
    // talk to its delegate
    if (cv.delegate && 
        [cv.delegate respondsToSelector:
             @selector(collectionView:performAction:forItemAtIndexPath:withSender:)])
        [cv.delegate collectionView:cv performAction:_cmd
             forItemAtIndexPath:ip withSender:sender];
}