Invalid context when creating UIImageView

问题

I have an error when I tried to create a UIImageView. Look at this code :

UIImage* backgroundPanel = [[UIImage imageNamed:@"loginPanelBackground.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(90, 0, 149, 416)];

self.connexionBackgroundImgView = [[UIImageView alloc] initWithImage:backgroundPanel];
self.connexionBackgroundImgView.frame = CGRectMake(0, 0, 416, 390); // THIS LINE PROVOC THE INVALID CONTEXT
[self.connexionView insertSubview:self.connexionBackgroundImgView aboveSubview:self.connexionToCreationCompteView];

It throws this error in the log :

<Error>: CGContextSaveGState: invalid context 0x0
<Error>: CGContextSetBlendMode: invalid context 0x0
<Error>: CGContextSetAlpha: invalid context 0x0
<Error>: CGContextTranslateCTM: invalid context 0x0
<Error>: CGContextScaleCTM: invalid context 0x0
<Error>: CGContextGetCTM: invalid context 0x0
<Error>: CGContextSaveGState: invalid context 0x0
<Error>: CGContextClipToRect: invalid context 0x0
<Error>: CGContextDrawTiledImage: invalid context 0x0
<Error>: CGContextRestoreGState: invalid context 0x0
<Error>: CGContextGetCTM: invalid context 0x0
<Error>: CGContextSaveGState: invalid context 0x0
<Error>: CGContextClipToRect: invalid context 0x0
<Error>: CGContextDrawTiledImage: invalid context 0x0
<Error>: CGContextRestoreGState: invalid context 0x0
<Error>: CGContextGetCTM: invalid context 0x0
<Error>: CGContextSaveGState: invalid context 0x0
<Error>: CGContextClipToRect: invalid context 0x0
<Error>: CGContextDrawTiledImage: invalid context 0x0
<Error>: CGContextRestoreGState: invalid context 0x0
<Error>: CGContextRestoreGState: invalid context 0x0

I had this error only on the iPad, not with the Simulator, I don't understand.. :/

回答1:

I had this problem until I found out that my cap inset argument to resizableImageWithCapInsets: was wrong — it didn't leave any un-capped area at all (you need at least 1x1 pixel not covered by a cap). So make sure that:

(insets.left + insets.right) < width

and

(insets.top + insets.bottom) < height

回答2:

The Simulator is case-insensitive. The device is case-sensitive. The png is named correctly? Maybe it is 'Login' with a capital L.

回答3:

See the answer here : How do I capture UIImage of complete contents of UITableView / UIScrollView and make it work on an ios device

Thanks eliajf !

回答4:

I still can't comment due to low rep. However I'd like to add to neon1's answer which helped me a lot.

You also need to make sure that all of the insets are greater than zero.

insets.left > 0

insets.top > 0

insets.right > 0

insets.bottom > 0

来源：https://stackoverflow.com/questions/13183904/invalid-context-when-creating-uiimageview

标签

ios

uiimageview

uiimage

cgcontext