stretchableImageWithLeftCapWidth：topCapHeight在initWithCoder中不起作用：UIImageView子类(stretchableImageWithL

stretchableImageWithLeftCapWidth：topCapHeight在initWithCoder中不起作用：UIImageView子类(stretchableImageWithLeftCapWidth:topCapHeight doesn't work in initWithCoder: of UIImageView subclass)

我有一个名为ShadowView的UIImageView子类，它显示可以在任何东西下使用的阴影。 ShadowViews将从笔尖加载。

在initWithCoder：中，我有以下代码：

- (id)initWithCoder:(NSCoder *)decoder { self = [super initWithCoder:decoder]; if (self != nil) { UIImage *shadowImage = [[UIImage imageNamed:@"drop_shadow_4_pix.png"] stretchableImageWithLeftCapWidth:4 topCapHeight:4]; [self setContentMode:UIViewContentModeScaleToFill]; [self setImage:shadowImage]; } return self; }

但是，当我运行应用程序时，此图像不会出现。

但是，如果我改变它

... UIImage *shadowImage = [UIImage imageNamed:@"drop_shadow_4_pix.png"]; ...

它工作正常，但它被拉错了。

有关为什么会发生这种情况的任何想法？

编辑：当我以编程方式加载shadowview时，使用initWithFrame：与initWithCoder类似地实现：

另一个编辑：我想我解决了这个问题。 我需要设置自动调整遮罩。

I have a UIImageView subclass called ShadowView, which displays a shadow that can be used under anything. ShadowViews are to be loaded from a nib.

In initWithCoder:, I have the following code:

- (id)initWithCoder:(NSCoder *)decoder { self = [super initWithCoder:decoder]; if (self != nil) { UIImage *shadowImage = [[UIImage imageNamed:@"drop_shadow_4_pix.png"] stretchableImageWithLeftCapWidth:4 topCapHeight:4]; [self setContentMode:UIViewContentModeScaleToFill]; [self setImage:shadowImage]; } return self; }

When I run the app, though, this image does not appear.

But if I change it to

... UIImage *shadowImage = [UIImage imageNamed:@"drop_shadow_4_pix.png"]; ...

it works fine, but it is stretched wrong.

Any ideas as to why this is happening?

Edit: it is the same when I load the shadowview programmatically, with initWithFrame: implemented similarly to initWithCoder:.

Another Edit: I think I solved the problem. I needed to set the autoresizing masks.

最满意答案

shadowImage是否为零？

UIImage *shadowImage = [[UIImage imageNamed:@"drop_shadow_4_pix.png"] stretchableImageWithLeftCapWidth:4 topCapHeight:4];

如果基本图像小于5像素宽或5像素高，则该方法可以返回nil，因为它需要4个像素用于大写字母+ 1个像素来拉伸。

Is shadowImage nil?

UIImage *shadowImage = [[UIImage imageNamed:@"drop_shadow_4_pix.png"] stretchableImageWithLeftCapWidth:4 topCapHeight:4];

That method could return nil if the base image is less than 5 pixels wide or 5 pixels tall since it needs the 4 pixels for the caps + 1 pixel to stretch.