iOS 7：UITableViewController：更改/替换删除按钮

Question

免责声明：我知道调整这类内容不是一种最佳做法，因为它可能会因Apple决定改变其内部行为而中断。

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

在查看控件层次结构时，我可以看到UITableViewCellScrollView中有一个UITableViewCellDeleteConfirmationView。但是通过查看layoutSubviews或willTransitionToState中的SubViews集合，只有我自己的视图，UITableViewCellDeleteConfirmationView不会出现。

那么，有没有人想出如何修改默认删除按钮/视图？

Answer 1

我知道您可能不想覆盖Apples整个实现以编辑表格视图单元格但是我的应用程序遇到了类似的问题。在我的情况下，当用户从左向右滑动时，我需要两个按钮（更多和丢失），就像在iOS7的新提醒应用程序中一样。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，用于隐藏顶层下方的按钮，并使用平移手势识别器移动顶层，显示下方的按钮。因此，我可以完全控制显示哪些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。

Answer 2

您没有在layoutSubviews或willTransitionToState:中看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“看到”它，您需要推迟一些浏览视图层次结构的代码，并允许操作系统在此期间创建/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Apple的内部实现，可能会随时更改。

在这里看到一个（几乎）完整的例子：

Customizing iOS 7 Delete button

Answer 3

不确定这是否适用于ios 7，但请看一下：

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

  if (editingStyle == UITableViewCellEditingStyleDelete)

   {

    //   Your Code

    }
}