为什么视图的淡出效果不起作用？

Question

我将内容作为documenView添加到滚动视图中，并使用以下代码来淡出我的documentView：

- (IBAction)deleteAllRules:(id)sender {

    NSViewAnimation * deleteListOfRulesViewAnimation;
    NSRect viewRect;
    NSMutableDictionary* animDict;

    // Create the attributes dictionary
    animDict = [NSMutableDictionary dictionaryWithCapacity:3];
    viewRect = listOfRulesView.frame;

    // Specify which view to modify.
    [animDict setObject:listOfRulesView forKey:NSViewAnimationTargetKey];

    // Specify the starting position of the view.
    [animDict setObject:[NSValue valueWithRect:viewRect] forKey:NSViewAnimationStartFrameKey];

    // Shrink the view from its current size to nothing.
    NSRect viewZeroSize = listOfRulesView.frame;
    viewZeroSize.size.width = 0;
    viewZeroSize.size.height = 0;
    [animDict setObject:[NSValue valueWithRect:viewZeroSize] forKey:NSViewAnimationEndFrameKey];

    // Set this view to fade out
    [animDict setObject:NSViewAnimationFadeOutEffect forKey:NSViewAnimationEffectKey];

    // Create the view animation object.
    deleteListOfRulesViewAnimation = [[NSViewAnimation alloc] initWithViewAnimations:[NSArray
                                                               arrayWithObjects:animDict, nil]];
    // Set some additional attributes for the animation.
    [deleteListOfRulesViewAnimation setDuration:1.5];    // One and a half seconds.
    [deleteListOfRulesViewAnimation setAnimationCurve:NSAnimationEaseIn];
    [deleteListOfRulesViewAnimation setDelegate:self];

    // Run the animation.
    [deleteListOfRulesViewAnimation startAnimation];

    // The animation has finished, so go ahead and release it.
    [deleteListOfRulesViewAnimation release];

}

但是在没有淡出效果的情况下查看隐藏。为什么？

Answer 1

对于10.5+代码，建议使用核心动画。

使用核心动画的最简单方法是使用动画器代理。例如，可以通过设置视图的alpha值动画来实现淡出效果：

[[myView animator] setAlpaValue:0.0f]

您可以使用以下命令更改动画持续时间：

[[NSAnimationContext currentContext] setDuration:0.4f]