直接上代码了 头文件
- // 图片处理 0 半灰色 1 灰度 2 深棕色 3 反色
- +(UIImage*)imageWithImage:(UIImage*)image grayLevelType:(UIImageGrayLevelType)type;
- //色值 变暗多少 0.0 - 1.0
- +(UIImage*)imageWithImage:(UIImage*)image darkValue:(float)darkValue;
- /**
- 获取网络图片的Size, 先通过文件头来获取图片大小
- 如果失败 会下载完整的图片Data 来计算大小 所以最好别放在主线程
- 如果你有使用SDWebImage就会先看下 SDWebImage有缓存过改图片没有
- 支持文件头大小的格式 png、gif、jpg http://www.cocoachina.com/bbs/read.php?tid=165823
- */
- +(CGSize)downloadImageSizeWithURL:(id)imageURL;
代码实现:
- //讨厌警告
- -(id)diskImageDataBySearchingAllPathsForKey:(id)key{return nil;}
- +(CGSize)downloadImageSizeWithURL:(id)imageURL
- {
- NSURL* URL = nil;
- if([imageURL isKindOfClass:[NSURL class]]){
- URL = imageURL;
- }
- if([imageURL isKindOfClass:[NSString class]]){
- URL = [NSURL URLWithString:imageURL];
- }
- if(URL == nil)
- return CGSizeZero;
- NSString* absoluteString = URL.absoluteString;
- #ifdef dispatch_main_sync_safe
- if([[SDImageCache sharedImageCache] diskImageExistsWithKey:absoluteString])
- {
- UIImage* image = [[SDImageCache sharedImageCache] imageFromMemoryCacheForKey:absoluteString];
- if(!image)
- {
- NSData* data = [[SDImageCache sharedImageCache] performSelector:@selector(diskImageDataBySearchingAllPathsForKey:) withObject:URL.absoluteString];
- image = [UIImage imageWithData:data];
- }
- if(image)
- {
- return image.size;
- }
- }
- #endif
- NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:URL];
- NSString* pathExtendsion = [URL.pathExtension lowercaseString];
- CGSize size = CGSizeZero;
- if([pathExtendsion isEqualToString:@"png"]){
- size = [self downloadPNGImageSizeWithRequest:request];
- }
- else if([pathExtendsion isEqual:@"gif"])
- {
- size = [self downloadGIFImageSizeWithRequest:request];
- }
- else{
- size = [self downloadJPGImageSizeWithRequest:request];
- }
- if(CGSizeEqualToSize(CGSizeZero, size))
- {
- NSData* data = [NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:URL] returningResponse:nil error:nil];
- UIImage* image = [UIImage imageWithData:data];
- if(image)
- {
- #ifdef dispatch_main_sync_safe
- [[SDImageCache sharedImageCache] storeImage:image recalculateFromImage:YES imageData:data forKey:URL.absoluteString toDisk:YES];
- #endif
- size = image.size;
- }
- }
- return size;
- }
- +(CGSize)downloadPNGImageSizeWithRequest:(NSMutableURLRequest*)request
- {
- [request setValue:@"bytes=16-23" forHTTPHeaderField:@"Range"];
- NSData* data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
- if(data.length == 8)
- {
- int w1 = 0, w2 = 0, w3 = 0, w4 = 0;
- [data getBytes:&w1 range:NSMakeRange(0, 1)];
- [data getBytes:&w2 range:NSMakeRange(1, 1)];
- [data getBytes:&w3 range:NSMakeRange(2, 1)];
- [data getBytes:&w4 range:NSMakeRange(3, 1)];
- int w = (w1 << 24) + (w2 << 16) + (w3 << 8) + w4;
- int h1 = 0, h2 = 0, h3 = 0, h4 = 0;
- [data getBytes:&h1 range:NSMakeRange(4, 1)];
- [data getBytes:&h2 range:NSMakeRange(5, 1)];
- [data getBytes:&h3 range:NSMakeRange(6, 1)];
- [data getBytes:&h4 range:NSMakeRange(7, 1)];
- int h = (h1 << 24) + (h2 << 16) + (h3 << 8) + h4;
- return CGSizeMake(w, h);
- }
- return CGSizeZero;
- }
- +(CGSize)downloadGIFImageSizeWithRequest:(NSMutableURLRequest*)request
- {
- [request setValue:@"bytes=6-9" forHTTPHeaderField:@"Range"];
- NSData* data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
- if(data.length == 4)
- {
- short w1 = 0, w2 = 0;
- [data getBytes:&w1 range:NSMakeRange(0, 1)];
- [data getBytes:&w2 range:NSMakeRange(1, 1)];
- short w = w1 + (w2 << 8);
- short h1 = 0, h2 = 0;
- [data getBytes:&h1 range:NSMakeRange(2, 1)];
- [data getBytes:&h2 range:NSMakeRange(3, 1)];
- short h = h1 + (h2 << 8);
- return CGSizeMake(w, h);
- }
- return CGSizeZero;
- }
- +(CGSize)downloadJPGImageSizeWithRequest:(NSMutableURLRequest*)request
- {
- [request setValue:@"bytes=0-209" forHTTPHeaderField:@"Range"];
- NSData* data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
- if ([data length] <= 0x58) {
- return CGSizeZero;
- }
- if ([data length] < 210) {// 肯定只有一个DQT字段
- short w1 = 0, w2 = 0;
- [data getBytes:&w1 range:NSMakeRange(0x60, 0x1)];
- [data getBytes:&w2 range:NSMakeRange(0x61, 0x1)];
- short w = (w1 << 8) + w2;
- short h1 = 0, h2 = 0;
- [data getBytes:&h1 range:NSMakeRange(0x5e, 0x1)];
- [data getBytes:&h2 range:NSMakeRange(0x5f, 0x1)];
- short h = (h1 << 8) + h2;
- return CGSizeMake(w, h);
- } else {
- short word = 0x0;
- [data getBytes:&word range:NSMakeRange(0x15, 0x1)];
- if (word == 0xdb) {
- [data getBytes:&word range:NSMakeRange(0x5a, 0x1)];
- if (word == 0xdb) {// 两个DQT字段
- short w1 = 0, w2 = 0;
- [data getBytes:&w1 range:NSMakeRange(0xa5, 0x1)];
- [data getBytes:&w2 range:NSMakeRange(0xa6, 0x1)];
- short w = (w1 << 8) + w2;
- short h1 = 0, h2 = 0;
- [data getBytes:&h1 range:NSMakeRange(0xa3, 0x1)];
- [data getBytes:&h2 range:NSMakeRange(0xa4, 0x1)];
- short h = (h1 << 8) + h2;
- return CGSizeMake(w, h);
- } else {// 一个DQT字段
- short w1 = 0, w2 = 0;
- [data getBytes:&w1 range:NSMakeRange(0x60, 0x1)];
- [data getBytes:&w2 range:NSMakeRange(0x61, 0x1)];
- short w = (w1 << 8) + w2;
- short h1 = 0, h2 = 0;
- [data getBytes:&h1 range:NSMakeRange(0x5e, 0x1)];
- [data getBytes:&h2 range:NSMakeRange(0x5f, 0x1)];
- short h = (h1 << 8) + h2;
- return CGSizeMake(w, h);
- }
- } else {
- return CGSizeZero;
- }
- }
- }
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