TableView长按拖动Cell改变位置

2019-05-09  本文已影响0人  这位网友

需要实现简单的cell拖动效果
首先是在你的TableView上添加长按手势,然后实现长按手势就可以了

一、添加长按手势
UILongPressGestureRecognizer *longTap = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handlelongGesture:)];
[_tableView addGestureRecognizer:longTap];
二、实现长按拖动效果
#pragma mark - Cell拖动排序
- (void)handlelongGesture:(UILongPressGestureRecognizer *)sender
{
    UILongPressGestureRecognizer *longPress = (UILongPressGestureRecognizer *)sender;
    UIGestureRecognizerState state = longPress.state;
    
    CGPoint location = [sender locationInView:self.tableView];
    NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:location];
    
    static UIView *snapshot = nil;
    static NSIndexPath *sourceIndexPath = nil;
    
    switch (state) {
        case UIGestureRecognizerStateBegan: {
            if (indexPath) {
                sourceIndexPath = indexPath;
                UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
                
                // Take a snapshot of the selected row using helper method.
                snapshot = [self customSnapshoFromView:cell];
                
                // Add the snapshot as subview, centered at cell's center...
                __block CGPoint center = cell.center;
                snapshot.center = center;
                snapshot.alpha = 0.0;
                [self.tableView addSubview:snapshot];
                [UIView animateWithDuration:0.25 animations:^{
                    // Offset for gesture location.
                    center.y = location.y;
                    snapshot.center = center;
                    snapshot.transform = CGAffineTransformMakeScale(1.05, 1.05);
                    snapshot.alpha = 0.98;
                    
                    cell.alpha = 0.0f;
                    
                } completion:^(BOOL finished) {
                    cell.hidden = YES;
                }];
            }
            break;
        }
            
        case UIGestureRecognizerStateChanged: {
            CGPoint center = snapshot.center;
            center.y = location.y;
            snapshot.center = center;
            // Is destination valid and is it different from source?
            if (indexPath && ![indexPath isEqual:sourceIndexPath]) {
                // ... update data source.
                // 这里需要注意,我是以section为单位写的
                [self.dateList exchangeObjectAtIndex:indexPath.section withObjectAtIndex:sourceIndexPath.section];
                // ... move the rows.
                // 你要看你是拖动section还是拖动row了[]([]())
                // [self.tableView moveRowAtIndexPath:sourceIndexPath toIndexPath:indexPath];
                [self.tableView moveSection:sourceIndexPath.section toSection:indexPath.section];
                // ... and update source so it is in sync with UI changes.
                sourceIndexPath = indexPath;
            }
            break;
        }
        
        default: {
            // Clean up.
            UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:sourceIndexPath];
            [UIView animateWithDuration:0.25 animations:^{
                snapshot.center = cell.center;
                snapshot.transform = CGAffineTransformIdentity;
                snapshot.alpha = 0.0;
                cell.alpha = 1.0f;
            } completion:^(BOOL finished) {
                cell.hidden = NO;
                [snapshot removeFromSuperview];
                snapshot = nil;
            }];
            sourceIndexPath = nil;
            break;
        }
    }
}

- (UIView *)customSnapshoFromView:(UIView *)inputView
{
    UIView *snapshot = nil;
    if ([[[UIDevice currentDevice] systemVersion] doubleValue] < 7.0) {
        //ios7.0 以下通过截图形式保存快照
        snapshot = [self customSnapShortFromViewEx:inputView];
    }else{
        //ios7.0 系统的快照方法
        snapshot = [inputView snapshotViewAfterScreenUpdates:YES];
    }
    
    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;
}

- (UIView *)customSnapShortFromViewEx:(UIView *)inputView
{
    CGSize inSize = inputView.bounds.size;
    // 下面方法,第一个参数表示区域大小。第二个参数表示是否是非透明的。如果需要显示半透明效果,需要传NO,否则传YES。第三个参数就是屏幕密度了
    UIGraphicsBeginImageContextWithOptions(inSize, NO, [UIScreen mainScreen].scale);
    [inputView.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image= UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    UIImageView* snapshot = [[UIImageView alloc] initWithImage:image];
    
    return snapshot;
}

参考自:iOS-TableView拖动Cell更换次序

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