UITabView内部元素拖动

UITabView内部元素拖动

1加手势识别器

- (void)longPressGestureRecognized:(id)sender{
    UILongPressGestureRecognizer *longPress = (UILongPressGestureRecognizer *)sender;
    UIGestureRecognizerState longPressState = longPress.state;
    //手指在tableView中的位置
    _fingerLocation = [longPress locationInView:self];
    //手指按住位置对应的indexPath，可能为nil
    _relocatedIndexPath = [self indexPathForRowAtPoint:_fingerLocation];
    switch (longPressState) {
        case UIGestureRecognizerStateBegan:{  
        //手势开始，对被选中cell截图，隐藏原cell
            break;
        }
        case UIGestureRecognizerStateChanged:{
        //点击位置移动，判断手指按住位置是否进入其它indexPath范围，若进入则更新数据源并移动cell
        //必须更具位置动态更新数据源
				break;
        }
        default: {                             
        //长按手势结束或被取消，移除截图，显示cell
            break;
        }
    }
}

2将cell截图

/** 返回一个给定view的截图. */
- (UIView *)customSnapshotFromView:(UIView *)inputView {
    
    // Make an image from the input view.
    UIGraphicsBeginImageContextWithOptions(inputView.bounds.size, NO, 0);
    [inputView.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    // Create an image view.
    UIView *snapshot = [[UIImageView alloc] initWithImage:image];
    snapshot.center = inputView.center;
    snapshot.layer.masksToBounds = NO;
    snapshot.layer.cornerRadius = 0.0;
    snapshot.layer.shadowOffset = CGSizeMake(-5.0, 0.0);
    snapshot.layer.shadowRadius = 5.0;
    snapshot.layer.shadowOpacity = 0.4;
    
    return snapshot;
}

3定时器score位置更新

- (void)startAutoScroll{
    CGFloat pixelSpeed = 4;
    if (_autoScrollDirection == PKSnapshotMeetsEdgeTop) {//向下滚动
        if (self.contentOffset.y > 0) {//向下滚动最大范围限制
            [self setContentOffset:CGPointMake(0, self.contentOffset.y - pixelSpeed)];
            _snapshot.center = CGPointMake(_snapshot.center.x, _snapshot.center.y - pixelSpeed);
        }
    }else{                                               //向上滚动
        if (self.contentOffset.y + self.bounds.size.height < self.contentSize.height) {//向下滚动最大范围限制
            [self setContentOffset:CGPointMake(0, self.contentOffset.y + pixelSpeed)];
            _snapshot.center = CGPointMake(_snapshot.center.x, _snapshot.center.y + pixelSpeed);
        }
    }
    
    /*  当把截图拖动到边缘，开始自动滚动，如果这时手指完全不动，则不会触发‘UIGestureRecognizerStateChanged’，对应的代码就不会执行，导致虽然截图在tableView中的位置变了，但并没有移动那个隐藏的cell，用下面代码可解决此问题，cell会随着截图的移动而移动
     */
    _relocatedIndexPath = [self indexPathForRowAtPoint:_snapshot.center];
    if (_relocatedIndexPath && ![_relocatedIndexPath isEqual:_originalIndexPath]) {
        [self cellRelocatedToNewIndexPath:_relocatedIndexPath];
    }
}

4结束后处理数据