iOS 将PDF文件转成图片
- (void)footButtonAction
{
if ([self.downloadUrl isEqualToString:@""] || self.downloadUrl == nil || [self.downloadUrl isEqual:nil] || !self.downloadUrl) {
return;
}
NSURL * url = [[NSURL alloc] initWithString:self.downloadUrl];
CFURLRef ref = (__bridge CFURLRef)url;
CGPDFDocumentRef pdf = CGPDFDocumentCreateWithURL(ref);
CFRelease(ref);
CGImageRef imageRef = PDFPageToCGImage(1,pdf);
UIImage *amg = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
//保存图片到相册
UIImageWriteToSavedPhotosAlbum(amg, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
}
CGImageRef PDFPageToCGImage(size_t pageNumber, CGPDFDocumentRef document)
{
CGPDFPageRef page = CGPDFDocumentGetPage (document, pageNumber);
if(page)
{
CGRect pageSize =CGPDFPageGetBoxRect(page,kCGPDFMediaBox);
CGContextRef outContext= CreateARGBBitmapContext (pageSize.size.width, pageSize.size.height);
if(outContext)
{
CGContextDrawPDFPage(outContext, page);
CGImageRef ThePDFImage= CGBitmapContextCreateImage(outContext);
CFRelease(outContext);
return ThePDFImage;
}
}
return NULL;
}
CGContextRef CreateARGBBitmapContext (size_t pixelsWide, size_t pixelsHigh)
{
CGContextRef context = NULL;
CGColorSpaceRef colorSpace;
void * bitmapData;
unsigned long bitmapByteCount;
unsigned long bitmapBytesPerRow;
// Get image width, height. We’ll use the entire image.
// size_t pixelsWide = CGImageGetWidth(inImage);
// size_t pixelsHigh = CGImageGetHeight(inImage);
// Declare the number of bytes per row. Each pixel in the bitmap in this
// example is represented by 4 bytes; 8 bits each of red, green, blue, and
// alpha.
bitmapBytesPerRow = (pixelsWide * 4);
bitmapByteCount = (bitmapBytesPerRow * pixelsHigh);
// Use the generic RGB color space.
colorSpace =CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
if (colorSpace == NULL)
{
fprintf(stderr, "Error allocating color space\n");
return NULL;
}
// Allocate memory for image data. This is the destination in memory
// where any drawing to the bitmap context will be rendered.
bitmapData = malloc( bitmapByteCount );
if (bitmapData == NULL)
{
fprintf (stderr, "Memory not allocated!");
CGColorSpaceRelease( colorSpace );
return NULL;
}
// Create the bitmap context. We want pre-multiplied ARGB, 8-bits
// per component. Regardless of what the source image format is
// (CMYK, Grayscale, and so on) it will be converted over to the format
// specified here by CGBitmapContextCreate.
context = CGBitmapContextCreate (bitmapData,
pixelsWide,
pixelsHigh,
8, // bits per component
bitmapBytesPerRow,
colorSpace,
kCGImageAlphaPremultipliedFirst);
if (context == NULL)
{
free (bitmapData);
fprintf (stderr, "Context not created!");
}
// Make sure and release colorspace before returning
CGColorSpaceRelease( colorSpace );
return context;
}
// 功能：显示图片保存结果
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError*)error contextInfo:(void*)contextInfo
{
if (error){
hud.label.text = @"保存图片失败！";
}else {
hud.label.text = @"保存图片成功！";
}
}