滚动时动画子视图删除冻结

Posted 2023-02-24

【中文标题】滚动时动画子视图删除冻结

【英文标题】：Animation subview removal freezes when scrolling

【发布时间】：2016-01-04 00:24:59

【问题描述】：

我的代码：

我正在使用以下代码添加到购物篮动画：

-(void)triggerAddItemAnimation:(NSIndexPath*)indexPath

    //Cell that was pressed.
    CellMenuItem *cell = [self.tableView cellForRowAtIndexPath:indexPath];

    // grab the imageview using cell
    UIImageView *imgV = (UIImageView*)[cell viewWithTag:IDENTIFIER_ANIMATION_IMAGE];

    //Get the x-coordinate of the image.
    int xCoord = cell.imgAddButton.frame.origin.x;

    // get the exact location of image
    CGRect rect = [imgV.superview convertRect:imgV.frame fromView:nil];
    rect = CGRectMake(xCoord, (rect.origin.y*-1)-10, imgV.frame.size.width, imgV.frame.size.height);

    //NSLog(@"rect is %f,%f,%f,%f",rect.origin.x,rect.origin.y,rect.size.width,rect.size.height);

    // create new duplicate image
    UIImageView *starView = [[UIImageView alloc] initWithImage:imgV.image];
    [starView setFrame:rect];
    starView.layer.cornerRadius=5;
    starView.layer.borderColor=[[UIColor blackColor]CGColor];
    starView.layer.borderWidth=1;
    [self.view addSubview:starView];

    // begin ---- apply position animation
    CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
    pathAnimation.calculationMode = kCAAnimationPaced;
    pathAnimation.fillMode = kCAFillModeForwards;
    pathAnimation.removedOnCompletion = NO;
    pathAnimation.duration=0.65;
    pathAnimation.delegate=self;

    // tab-bar right side item frame-point = end point
    CGPoint endPoint = CGPointMake(self.lblBasketItemsCount.frame.origin.x, self.lblBasketItemsCount.frame.origin.y);

    CGMutablePathRef curvedPath = CGPathCreateMutable();
    CGPathMoveToPoint(curvedPath, NULL, starView.frame.origin.x, starView.frame.origin.y);
    CGPathAddCurveToPoint(curvedPath, NULL, endPoint.x, starView.frame.origin.y, endPoint.x, starView.frame.origin.y, endPoint.x, endPoint.y);
    pathAnimation.path = curvedPath;
    CGPathRelease(curvedPath);
    // end ---- apply position animation

    float animationDuration = 0.65f;

    // apply transform animation
    CABasicAnimation *basic=[CABasicAnimation animationWithKeyPath:@"transform"];
    [basic setToValue:[NSValue valueWithCATransform3D:CATransform3DMakeScale(0.25, 0.25, 0.25)]];
    [basic setAutoreverses:NO];
    [basic setDuration:animationDuration];

    [starView.layer addAnimation:pathAnimation forKey:@"curveAnimation"];
    [starView.layer addAnimation:basic forKey:@"transform"];

    //Remove the animation 0.05 before the animationDuration to remove clipping issue.
    [starView performSelector:@selector(removeFromSuperview) withObject:nil afterDelay:animationDuration - 0.05f];

问题：

动画效果很好，但是当我滚动时，用于动画的图像（取自单元格）在滚动停止之前不会从视图中移除。

被移除的子视图与方法中的最后一行代码一起被移除：

 [starView performSelector:@selector(removeFromSuperview) withObject:nil afterDelay:animationDuration - 0.05f];

我尝试过的：

我尝试过使用 GCD：

dispatch_async(dispatch_get_main_queue(), ^
           //call method here....
        );

如果我记得我相信我也尝试过带计时器的运行循环，以及在主线程上执行选择器。

我也试过把方法放在一个块中（不是我使用的实际代码，只是一个例子）：

 [UIView animateWithDuration:0.5
                          delay:1.0
                        options: UIViewAnimationCurveEaseOut
                     animations:^

                      
                     completion:^(BOOL finished)
                      //Remove subview here
                     ];

问题：

我可以推断出滚动占用了主线程，因此我尝试异步调用该方法。

谁能告诉我我做错了什么？

【参考方案1】：

要解决此问题，您可以使用块的完整部分，如上所示。我当时只是错误地使用了该块。

但是我解决这个问题的方法是，因为我无法让路径动画在块中工作，所以我将动画的委托设置为 self。

并使用以下内容：

- (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag

    [theView removeFromSuperview];