NSData+ImageContentType
獲取圖片的類(lèi)型，真實(shí)獲取圖片類(lèi)型的方式為獲取圖片第一個(gè)字節(jié)的內(nèi)容，第一個(gè)字節(jié)就是圖片類(lèi)型
+ (NSString *)sd_contentTypeForImageData:(NSData *)data {
uint8_t c;
[data getBytes:&c length:1];
switch (c) {
case 0xFF:
return @"image/jpeg";
case 0x89:
return @"image/png";
case 0x47:
return @"image/gif";
case 0x49:
case 0x4D:
return @"image/tiff";
case 0x52:
// R as RIFF for WEBP
if ([data length] < 12) {
return nil;
}
NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding];
if ([testString hasPrefix:@"RIFF"] && [testString hasSuffix:@"WEBP"]) {
return @"image/webp";
}
return nil;
}
return nil;
}
UIImage+GIF
將image返回成gif格式的圖片
將image轉(zhuǎn)換成NSData，再通過(guò)一下代碼獲取到gif圖片中有多少?gòu)垐D片
CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
size_t count = CGImageSourceGetCount(source);
然后將gif中的圖片分別取出來(lái)，然后放入一個(gè)數(shù)組
NSMutableArray *images = [NSMutableArray array];
NSTimeInterval duration = 0.0f;
for (size_t i = 0; i < count; i++) {
CGImageRef image = CGImageSourceCreateImageAtIndex(source, i, NULL);
if (!image) {
continue;
}
duration += [self sd_frameDurationAtIndex:i source:source];
[images addObject:[UIImage imageWithCGImage:image scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp]];
CGImageRelease(image);
}
獲取gif兩張圖片之間的間隔
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #e7e8eb}p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #29a09f}p.p3 {margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #e7e8eb; min-height: 15.0px}p.p4 {margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #51c34f}p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Menlo; color: #6544e9}span.s1 {font-variant-ligatures: no-common-ligatures}span.s2 {font-variant-ligatures: no-common-ligatures; color: #e12da0}span.s3 {font-variant-ligatures: no-common-ligatures; color: #29a09f}span.s4 {font-variant-ligatures: no-common-ligatures; color: #00aaa3}span.s5 {font-variant-ligatures: no-common-ligatures; color: #e7e8eb}span.s6 {font-variant-ligatures: no-common-ligatures; color: #51c34f}span.s7 {font-variant-ligatures: no-common-ligatures; color: #6544e9}
+ (float)sd_frameDurationAtIndex:(NSUInteger)index source:(CGImageSourceRef)source {
float frameDuration = 0.1f;
CFDictionaryRef cfFrameProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil);
NSDictionary *frameProperties = (__bridge NSDictionary *)cfFrameProperties;
NSDictionary *gifProperties = frameProperties[(NSString *)kCGImagePropertyGIFDictionary];
NSNumber *delayTimeUnclampedProp = gifProperties[(NSString *)kCGImagePropertyGIFUnclampedDelayTime];
if (delayTimeUnclampedProp) {
frameDuration = [delayTimeUnclampedProp floatValue];
}
else {
NSNumber *delayTimeProp = gifProperties[(NSString *)kCGImagePropertyGIFDelayTime];
if (delayTimeProp) {
frameDuration = [delayTimeProp floatValue];
}
}
// Many annoying ads specify a 0 duration to make an image flash as quickly as possible.
// We follow Firefox's behavior and use a duration of 100 ms for any frames that specify
// a duration of <= 10 ms. See <rdar://problem/7689300> and <http://webkit.org/b/36082>
// for more information.
if (frameDuration < 0.011f) {
frameDuration = 0.100f;
}
CFRelease(cfFrameProperties);
return frameDuration;
}
最后將獲取到的圖片數(shù)組重新組合成一個(gè)gif圖片
if (!duration) {
duration = (1.0f / 10.0f) * count;
}
animatedImage = [UIImage animatedImageWithImages:images duration:duration];
+ (UIImage *)sd_animatedGIFWithData:(NSData *)data {
if (!data) {
return nil;
}
CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
size_t count = CGImageSourceGetCount(source);
UIImage *animatedImage;
if (count <= 1) {
animatedImage = [[UIImage alloc] initWithData:data];
}
else {
NSMutableArray *images = [NSMutableArray array];
NSTimeInterval duration = 0.0f;
for (size_t i = 0; i < count; i++) {
CGImageRef image = CGImageSourceCreateImageAtIndex(source, i, NULL);
if (!image) {
continue;
}
duration += [self sd_frameDurationAtIndex:i source:source];
[images addObject:[UIImage imageWithCGImage:image scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp]];
CGImageRelease(image);
}
if (!duration) {
duration = (1.0f / 10.0f) * count;
}
animatedImage = [UIImage animatedImageWithImages:images duration:duration];
}
CFRelease(source);
return animatedImage;
}
UIImage+MultiFormat
主要是將不同格式的圖片進(jìn)行重新組合，gif的圖片用gif的方式組合，一般圖片則根據(jù)圖片方位進(jìn)行設(shè)置重新設(shè)置圖片
圖片方向
+(UIImageOrientation)sd_imageOrientationFromImageData:(NSData *)imageData {
UIImageOrientation result = UIImageOrientationUp;
CGImageSourceRef imageSource = CGImageSourceCreateWithData((__bridge CFDataRef)imageData, NULL);
if (imageSource) {
CFDictionaryRef properties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, NULL);
if (properties) {
CFTypeRef val;
int exifOrientation;
val = CFDictionaryGetValue(properties, kCGImagePropertyOrientation);
if (val) {
CFNumberGetValue(val, kCFNumberIntType, &exifOrientation);
result = [self sd_exifOrientationToiOSOrientation:exifOrientation];
} // else - if it's not set it remains at up
CFRelease((CFTypeRef) properties);
} else {
//NSLog(@"NO PROPERTIES, FAIL");
}
CFRelease(imageSource);
}
return result;
}
+ (UIImageOrientation) sd_exifOrientationToiOSOrientation:(int)exifOrientation {
UIImageOrientation orientation = UIImageOrientationUp;
switch (exifOrientation) {
case 1:
orientation = UIImageOrientationUp;
break;
case 3:
orientation = UIImageOrientationDown;
break;
case 8:
orientation = UIImageOrientationLeft;
break;
case 6:
orientation = UIImageOrientationRight;
break;
case 2:
orientation = UIImageOrientationUpMirrored;
break;
case 4:
orientation = UIImageOrientationDownMirrored;
break;
case 5:
orientation = UIImageOrientationLeftMirrored;
break;
case 7:
orientation = UIImageOrientationRightMirrored;
break;
default:
break;
}
return orientation;
}
