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我的应用程序需要从加载的 webview 中获取屏幕截图。图像保存时偶尔会出现一个错误。consol 日志如下：

    2013-06-04 20:12:33.093 iBookMark[5895:707] thumbnail img save over
ImageIO: <ERROR>  CGImageSourceCreateWithData data parameter is nil
ImageIO: <ERROR>  CGImageSourceCreateWithData data parameter is nil
ImageIO: <ERROR>  CGImageSourceCreateWithData data parameter is nil
ImageIO: <ERROR>  CGImageSourceCreateWithData data parameter is nil
ImageIO: <ERROR>  CGImageSourceCreateWithData data parameter is nil
ImageIO: <ERROR>  CGImageSourceCreateWithData data parameter is nil
ImageIO: <ERROR>  CGImageSourceCreateWithData data parameter is nil
ImageIO: <ERROR>  CGImageSourceCreateWithData data parameter is nil
ImageIO: <ERROR>  CGImageSourceCreateWithData data parameter is nil
ImageIO: <ERROR>  CGImageSourceCreateWithData data parameter is nil
2013-06-04 20:12:48.987 iBookMark[5895:707] [IMKInputSession activate] exception caught.
    IMKInputSession: <IMKInputSession: 0x102124cc0> -- 
    NSPortTimeoutException : connection timeout: did not receive reply
2013-06-04 20:12:53.989 iBookMark[5895:707] [IMKInputSession setValue:forTag:] exception caught.
    NSPortTimeoutException : connection timeout: did not receive reply

为什么这个错误可能会发生以及如何修复它？谢谢。

更新：这是我的截图代码。

    /*the sender is a webView,this function is called in the 
    WebView's delegate method naming webView: didFinishLoadForFrame:.*/

        [sender setMediaStyle:@"screen"];
        [sender lockFocus];

        NSData* data = [webView dataWithPDFInsideRect:[webView bounds]];
        if (data == nil) {
            return;
        }

        [sender unlockFocus];
        [sender setMediaStyle:@"savedMediaStyle"];
        NSImage *img = [[NSImage alloc] initWithData:data];
        [img setCacheMode:NSImageCacheNever];

        NSData* imageData = [img TIFFRepresentation];
        NSImage* tmpImg = [[NSImage alloc] initWithData:imageData];

        [img release];
        NSData* pngData = [NSImage compressImage:tmpImg size:NSMakeSize(SmallThumbnailWidth, SmallThumbnailHeight) factor:0.2];
        [tmpImg release];
        NSString* thumbnailPath = [PathManager getThumbnailPath];


        NSString* imageFilePath = [NSString stringWithFormat:@"%@/%ld.png",thumbnailPath,bookmark.bmId];


        [pngData writeToFile:imageFilePath atomically:NO];
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1 回答 1

-3

我想我已经找到了这个问题的答案。我创建了一个NSImage对象，发现它在使用时可能会变成 nil。这是导致的原因。ImageIO Error我已经修复了这个 bug。

于 2013-06-08T08:32:47.697 回答