Question

我确信我在做一些愚蠢的事情。我在UIButton之上构建了一个类别，我希望它能够获取分配给它的所有背景图像（不同的状态）并将它们转换为可伸缩版本并将它们重新应用回按钮。

- (void)enableBackgroundImageStrechingWithLeftCapWidth:(float)leftCapWidth withTopCapHeight:(float)topCapHeight;
{

    UIImage *backgroundimageNormal = [self backgroundImageForState:UIControlStateNormal];

    if (backgroundimageNormal != nil) 
    {
        UIImage *stretchImage = [backgroundimageNormal stretchableImageWithLeftCapWidth:leftCapWidth topCapHeight:topCapHeight];
        [self setBackgroundImage:stretchImage forState:UIControlStateNormal];
    }

    UIImage *backgroundimageSelected = [self backgroundImageForState:UIControlStateSelected];

    if (backgroundimageSelected != nil) 
    {
        UIImage *stretchImage = [backgroundimageSelected stretchableImageWithLeftCapWidth:leftCapWidth topCapHeight:topCapHeight];
        [self setBackgroundImage:stretchImage forState:UIControlStateSelected];
    }

    UIImage *backgroundimageHighlighted = [self backgroundImageForState:UIControlStateHighlighted];

    if (backgroundimageHighlighted != nil) 
    {
        UIImage *stretchImage = [backgroundimageHighlighted stretchableImageWithLeftCapWidth:leftCapWidth topCapHeight:topCapHeight];
        [self setBackgroundImage:stretchImage forState:UIControlStateHighlighted];
    }

    UIImage *backgroundimageDisabled = [self backgroundImageForState:UIControlStateDisabled];

    if (backgroundimageDisabled != nil) 
    {
        UIImage *stretchImage = [backgroundimageDisabled stretchableImageWithLeftCapWidth:leftCapWidth topCapHeight:topCapHeight];
        [self setBackgroundImage:stretchImage forState:UIControlStateDisabled];
    }
}

似乎工作，但按钮现在无法点击

Answer 1

似乎突出显示的状态会导致问题！

我删除了突出显示的块，它运行正常吗？

Answer 2

如果您没有突出显示/禁用状态的自定义图像，但依赖UIButton应用突出显示/禁用效果，则[self backgroundImageForState: UIControlStateHighlighted]将不会返回nil。它将返回一个指向正常状态图像的指针。

使用您的代码，您可以有效地为所有状态设置相同的图像。但是，它们看起来像是框架的自定义图像。这会禁用内置高亮/禁用效果。

Iphone：将可伸缩图像应用于按钮会禁用它

2 个答案: