NSViewAnimation进行视图和窗口动画

cocoa专门为视图和窗口动画提供了一个NSAnimation的子类：NSViewAnimation。通过设置属性字典就可以对窗口进行大小、位置、显示隐藏等动画。

//使用NSViewAnimation
- (IBAction)didViewAnimateClicked:(id)sender {
    //获取当前窗口大小
    NSRect firstFrame = [[NSApp mainWindow] frame];
    
    //属性字典
    NSMutableDictionary *dict = [NSMutableDictionary dictionary];
    
    //设置目标对象
    [dict setObject:[NSApp mainWindow] forKey:NSViewAnimationTargetKey];
    
    //设置其实大小
    [dict setObject:[NSValue valueWithRect:firstFrame] forKey:NSViewAnimationStartFrameKey];
    
    firstFrame.size.width = 50;
    firstFrame.size.height = 50;
    
    //设置最终大小
    [dict setObject:[NSValue valueWithRect:firstFrame] forKey:NSViewAnimationEndFrameKey];
    
    //设置动画效果
    [dict setObject:NSViewAnimationFadeOutEffect forKey:NSViewAnimationEffectKey];
    
    //设置动画
    NSViewAnimation *animation = [[NSViewAnimation alloc] initWithViewAnimations:[NSArray arrayWithObject:dict]];
    
    //启动动画
    [animation startAnimation];
}