一句话添加button高亮变淡，变色的效果

添加扩散动画

//button添加高亮
switch (i) {
    case 0:
    {
        title = @"默认变淡";
        [button addHighlightedFadeAlpha];
    }
        break;
    case 1:
    {
        title = @"自定变淡";
        [button addHighlightedFadeAlpha:0.3f];
    }
        break;
    case 2:
    {
        title = @"变白";
        [button addHighlightedFadeWhite];
    }
        break;
    case 3:
    {
        title = @"变黑";
        [button addHighlightedFadeBlack];
    }
        break;
    case 4:
    {
        title = @"变灰";
        [button addHighlightedFadeGray];
    }
        break;
    case 5:
    {
        title = @"变紫";
        button.diffusionAnimated = YES;
        [button addHighlightedFadeColor:[UIColor purpleColor] alpha:0.5f];
    }
        break;
    case 6:
    {
        title = @"变红";
        button.diffusionAnimated = YES;
        [button addHighlightedFadeColor:[UIColor redColor] alpha:1.0f];
    }
        break;
    case 7:
    {
        title = @"变蓝";
        [button addHighlightedFadeColor:[UIColor blueColor] alpha:0.5f];
    }
        break;
    case 8:
    {
        title = @"变绿";
        [button addHighlightedFadeColor:[UIColor greenColor] alpha:0.5f];
    }
        break;
    case 9:
    {
        title = @"变黄";
        [button addHighlightedFadeColor:[UIColor yellowColor] alpha:0.5f];
    }
        break;
    
    default:
        break;
}