iOS 7:UITableViewController:更改/替换删除按钮

Question

免责声明：我知道调整这类东西不是最佳做法，因为当苹果决定改变其内部行为时，它可能会崩溃。

有一些解决方案，比如https://stackoverflow.com/a/12511432/271150 这似乎适用于以前的iOS版本，但不适用于iOS 7。

当查看控件层次结构时，我可以看到UITableViewCellDeleteConfirmationView在UITableViewCellScrollView中。但是，通过查看在layoutSubview或将SubView集合的SubView只有我自己的视图，UITableViewCellDeleteConfirmationView不会出现。

那么，有人知道如何修改默认的删除按钮/视图了吗？

Answer 1

不确定这是否适用于iOS 7，但看看：

(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{

  if (editingStyle == UITableViewCellEditingStyleDelete)

   {

    //   Your Code

    }
}

Answer 2

在layoutSubviews或willTransitionState:中看不到视图的原因是删除按钮视图尚不存在，或者它还不是视图层次结构的一部分。为了“查看”视图，您需要稍微推迟浏览视图层次结构的代码，同时允许操作系统创建/添加视图：

- (void)willTransitionToState:(UITableViewCellStateMask)state
{
    [super willTransitionToState:state];

    if (state & UITableViewCellStateShowingDeleteConfirmationMask)
    {
        [self performSelector:@selector(findDeleteButtonViewThroughViewHierarchy:) withObject:self.subviews afterDelay:0];
    }
}

请注意，这是一个脆弱的解决方案，因为它基于苹果的内部实现，可能随时会发生变化。

在这里看到一个（几乎）完整的例子：

自定义iOS7删除按钮

Answer 3

我知道你可能不想覆盖苹果编辑表视图单元格的整个实现，但我的应用程序也有类似的问题。在我的例子中，当用户从左向右滑动时，我需要两个按钮（更多和丢失）来显示，就像iOS7的新提醒应用程序一样。而不是使用：

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath

我创建了一个自定义单元格，将按钮隐藏在顶层下，并使用平移手势识别器移动顶层，显示底层的按钮。因此，我可以完全控制显示的按钮以及它们的颜色等（见下文）。

static CGFloat const kEditButtonWidth = 82.0;

@interface MyCustomCell ()
@property (nonatomic, assign) CGFloat firstX;
@property (nonatomic, assign) CGFloat firstY;
@property (nonatomic, strong) UIView *topLayer;
@property (nonatomic, strong) UIButton *moreButton;
@property (nonatomic, strong) UIButton *lostButton;
@property (nonatomic, strong) UILabel *titleLabel;
@end

@implementation MyCustomCell

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier {
    self = [super initWithStyle:UITableViewCellStyleDefault reuseIdentifier:reuseIdentifier];
    if (self) {

        // BOTTOM LAYER (MORE AND LOST BUTTONS)
        UIButton *aButton = [UIButton buttonWithType:UIButtonTypeCustom];
        [aButton setFrame:CGRectZero];
        [aButton setTitle:@"More" forState:UIControlStateNormal];
        [aButton setTitleShadowColor:[UIColor clearColor] forState:UIControlStateNormal];
        [aButton setBackgroundColor:[UIColor colorWithRed:0.78 green:0.78 blue:0.78 alpha:1.0]];
        [[self contentView] addSubview:aButton];
        [self setMoreButton:aButton];

        aButton = [UIButton buttonWithType:UIButtonTypeCustom];
        [aButton setFrame:CGRectZero];
        [aButton setTitle:@"Lost" forState:UIControlStateNormal];
        [aButton setTitleShadowColor:[UIColor clearColor] forState:UIControlStateNormal];
        [aButton setBackgroundColor:[UIColor colorWithRed:1.00f green:0.23f blue:0.19f alpha:1.00f]];
        [[self contentView] addSubview:aButton];
        [self setLostButton:aButton];

        // TOP LAYER
        UIView *aView = [[UIView alloc] initWithFrame:CGRectZero];
        [aView setBackgroundColor:[UIColor whiteColor]];
        [[self contentView] addSubview:aView];
        [self setTopLayer:aView];

        UIPanGestureRecognizer *aPanRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGestureAction:)];
        [aPanRecognizer setMinimumNumberOfTouches:1];
        [aPanRecognizer setMaximumNumberOfTouches:1];
        [aView addGestureRecognizer:aPanRecognizer];

        // title label
        UILabel *aLabel = [[UILabel alloc] initWithFrame:CGRectZero];
        [aView addSubview:aLabel];
        [self setTitleLabel:aLabel];
    }
    return self;
}

- (void)layoutSubviews {

    [super layoutSubviews];

    CGRect bounds = [[self contentView] bounds];
    CGRect frame = CGRectZero;

    // BOTTOM LAYER (MORE AND LOST BUTTONS)
    frame.origin.x = bounds.size.width-(kEditButtonWidth+kEditButtonWidth); // two buttons wide
    frame.size.width = kEditButtonWidth;
    frame.size.height = bounds.size.height;
    [[self moreButton] setFrame:frame];

    frame.origin.x += kEditButtonWidth;
    [[self lostButton] setFrame:frame];

    // TOP LAYER
    frame = bounds;
    CGPoint anchorPoint = CGPointMake(0.0f, [[[self topLayer] layer] anchorPoint].y);
    [[[self topLayer] layer] setAnchorPoint:anchorPoint];
    [[self topLayer] setFrame:frame];

    // title label
    frame.origin.x = 20.0;
    frame.origin.y = 4.0;
    frame.size.width = bounds.size.width-40.0;
    frame.size.height = 21.0;
    [[self titleLabel] setFrame:frame];
}

- (void)panGestureAction:(id)sender {

    // on the first touch, get the center coordinates (x and y) of the view
    CGPoint translatedPoint = [(UIPanGestureRecognizer*)sender translationInView:self];
    if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan) {
        [self setFirstX:[[sender view] center].x];
        [self setFirstY:[[sender view] center].y];
    }

    // add translated point to reference points
    translatedPoint = CGPointMake([self firstX]+translatedPoint.x, [self firstY]);
    [[sender view] setCenter:translatedPoint];

    // when pan ends (set final x to be either back to zero or showing buttons)
    if ([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {
        CGFloat finalX = translatedPoint.x+(0.30*[(UIPanGestureRecognizer*)sender velocityInView:self].x);
        if (finalX < -1.0f*FMEditButtonWidth) {
            finalX = -2.0f*FMEditButtonWidth;
            [self setEditMode:YES];
        } else {
            finalX = 0.0f;
            [self setEditMode:NO];
        }

        // animate view
        [UIView animateWithDuration:1.0 delay:0.0 usingSpringWithDamping:1.0f initialSpringVelocity:1.0f options:UIViewAnimationOptionCurveEaseOut | UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionBeginFromCurrentState animations:^{
            [[sender view] setCenter:CGPointMake(finalX, [self firstY])];
        } completion:NULL];
    }
}

@end

希望这有帮助。