解決Ios載入大圖時出JPEG Corrupt JPEG data: premature end of data segment錯誤,導致載入時卡的問題。
阿新 • • 發佈:2019-02-05
如題,有時開執行緒載入大圖時,出如上錯誤(表象是某圖有一部分是灰色區域),導致載入時卡。
比方說你做圖片scrollview瀏覽時,滑動過程中建立大圖,出如上錯誤會卡。
解決辦法,用如下方法建立圖,就很流暢了。
CGImageRef MyCreateThumbnailImageFromData (NSData * data, int imageSize){
CGImageRef myThumbnailImage = NULL;
CGImageSourceRef myImageSource;
CFDictionaryRef myOptions = NULL;
CFStringRef myKeys[3];
CFTypeRef myValues[3];
CFNumberRef thumbnailSize;
// Create an image source from NSData; no options.
myImageSource = CGImageSourceCreateWithData((CFDataRef)data,
NULL);
// Make sure the image source exists before continuing.
if (myImageSource == NULL){
fprintf(stderr, "Image source is NULL.");
return NULL;
}
// Package the integer as a CFNumber object. Using CFTypes allows you
// to more easily create the options dictionary later.
thumbnailSize = CFNumberCreate(NULL, kCFNumberIntType, &imageSize);
// Set up the thumbnail options.
myKeys[0] = kCGImageSourceCreateThumbnailWithTransform;
myValues[0] = (CFTypeRef)kCFBooleanTrue;
myKeys[1] = kCGImageSourceCreateThumbnailFromImageIfAbsent;
myValues[1] = (CFTypeRef)kCFBooleanTrue;
myKeys[2] = kCGImageSourceThumbnailMaxPixelSize;
myValues[2] = (CFTypeRef)thumbnailSize;
myOptions = CFDictionaryCreate(NULL, (const void **) myKeys,
(const void **) myValues, 2,
&kCFTypeDictionaryKeyCallBacks,
& kCFTypeDictionaryValueCallBacks);
// Create the thumbnail image using the specified options.
myThumbnailImage = CGImageSourceCreateThumbnailAtIndex(myImageSource,
0,
myOptions);
// Release the options dictionary and the image source
// when you no longer need them.
CFRelease(thumbnailSize);
CFRelease(myOptions);
CFRelease(myImageSource);
// Make sure the thumbnail image exists before continuing.
if (myThumbnailImage == NULL){
fprintf(stderr, "Thumbnail image not created from image source.");
return NULL;
}
return myThumbnailImage;
}