GMGridView扩展心得

最新推荐文章于 2024-11-05 22:30:25 发布

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#gridview #uiscrollview #继承 #GMGridView

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本文详细介绍了如何针对GMGridView控件进行自定义响应事件优化，包括添加删除按钮、点击事件处理及编辑模式下事件响应逻辑的调整。

GMGridView继承于UIScrollView，很强大的一款控件（下载地址：https://github.com/gmoledina/GMGridView）

由于项目需求效果图如下：

由于要设计添加，删除按钮，于是修改了：

- (BOOL)GMGridView:(GMGridView *)gridView canDeleteItemAtIndex:(NSInteger)index

为委托函数的实现；

其次还有点击事件：

- (void)tapGestureUpdated:(UITapGestureRecognizer *)tapGesture

由于GMGridView在编辑时点击头像没有事件响应，于是自己继承GMGridView，重写父类方法：

父类方法如下：

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{    
    BOOL valid = YES;
    BOOL isScrolling = self.isDragging || self.isDecelerating;
    
    if (gestureRecognizer == _tapGesture) 
    {
        if (self.editing && self.disableEditOnEmptySpaceTap) {
             //原代码
            CGPoint locationTouch = [_tapGesture locationInView:self];
            NSInteger position = [self.layoutStrategy itemPositionFromLocation:locationTouch];
            valid = (position == GMGV_INVALID_POSITION);
        } else {
            valid = !isScrolling && !self.isEditing && ![_longPressGesture hasRecognizedValidGesture];
        }
    }
    else if (gestureRecognizer == _longPressGesture)
    {
        valid = (self.sortingDelegate || self.enableEditOnLongPress) && !isScrolling && !self.isEditing;
    }
    else if (gestureRecognizer == _sortingPanGesture) 
    {
        valid = (_sortMovingItem != nil && [_longPressGesture hasRecognizedValidGesture]);
    }
    else if(gestureRecognizer == _rotationGesture || gestureRecognizer == _pinchGesture || gestureRecognizer == _panGesture)
    {
        if (self.transformDelegate != nil && [gestureRecognizer numberOfTouches] == 2) 
        {
            CGPoint locationTouch1 = [gestureRecognizer locationOfTouch:0 inView:self];
            CGPoint locationTouch2 = [gestureRecognizer locationOfTouch:1 inView:self];
            
            NSInteger positionTouch1 = [self.layoutStrategy itemPositionFromLocation:locationTouch1];
            NSInteger positionTouch2 = [self.layoutStrategy itemPositionFromLocation:locationTouch2];
            
            valid = !self.isEditing && ([self isInTransformingState] || ((positionTouch1 == positionTouch2) && (positionTouch1 != GMGV_INVALID_POSITION)));
        }
        else
        {
            valid = NO;
        }
    }
    
    return valid;
}

自己继承后修改如下：

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
    BOOL valid = [super gestureRecognizerShouldBegin:gestureRecognizer];
    if (gestureRecognizer == self.tapGesture) {
        if (self.editing && self.disableEditOnEmptySpaceTap)
        {
            valid = YES;
        }
    }
    return valid;
}

这样

- (void)tapGestureUpdated:(UITapGestureRecognizer *)tapGesture 函数才能响应

#pragma mark Tap gesture
//////////////////////////////////////////////////////////////
//BOOL canEdit = self.editing && [self.dataSource GMGridView:self canDeleteItemAtIndex:position];
- (void)tapGestureUpdated:(UITapGestureRecognizer *)tapGesture
{
    CGPoint locationTouch = [_tapGesture locationInView:self];
    NSInteger position = [self.layoutStrategy itemPositionFromLocation:locationTouch];
    
    if (position != GMGV_INVALID_POSITION) 
    {
        if (!self.editing)
        {
            [self cellForItemAtIndex:position].highlighted = NO;
            [self.actionDelegate GMGridView:self didTapOnItemAtIndex:position];
        }
    }
    else
    { 
        if([self.actionDelegate respondsToSelector:@selector(GMGridViewDidTapOnEmptySpace:)])
        {
            [self.actionDelegate GMGridViewDidTapOnEmptySpace:self];
        }
        
        if (self.disableEditOnEmptySpaceTap) {
            self.editing = NO;
        }
    }
}

这里的 if (!self.editing) 也得注释才能响应事件