iOS-使用系统类库加载gif格式图片

来源：互联网发布：飞机时刻表查询软件编辑：程序博客网时间：2024/06/06 20:54

- (id)initWithFrame:(CGRect)frame filePath:(NSString *)_filePath{

self = [superinitWithFrame:frame];

if (self) {

*_filePath : gif路径

*data : 取得这个gif

NSData *data = [NSDatadataWithContentsOfFile:_filePath];

*gifLoopCount : 设置一个gif的循环属性 ,值为0

NSDictionary *gifLoopCount = [NSDictionarydictionaryWithObjectsAndKeys:

[NSNumbernumberWithInt:0] , (NSString *)kCGImagePropertyGIFLoopCount,nil

];

*创建gif属性

NSDictionary * gifProperties = [NSDictionarydictionaryWithObject:gifLoopCountforKey:(NSString *)kCGImagePropertyGIFDictionary] ;

*根据属性还有data 得到gif，并存在CGImageSourceRef中

* ColorModel = RGB;

* Depth = 8;//

* HasAlpha = 1;

* PixelHeight = 22;

* PixelWidth = 22;

* "{GIF}" = {

* DelayTime = "0.1";

* UnclampedDelayTime = "0.1";

* };

CGImageSourceRef gif = CGImageSourceCreateWithData((__bridge CFDataRef)(data), (__bridge CFDictionaryRef)gifProperties);

CFDictionaryRef gifprops =(CGImageSourceCopyPropertiesAtIndex(gif,0,NULL));

*count : gif的张数

NSInteger count =CGImageSourceGetCount(gif);

CFDictionaryRef gifDic =CFDictionaryGetValue(gifprops,kCGImagePropertyGIFDictionary);

*delay: 延迟时间？？

NSNumber * delay =CFDictionaryGetValue(gifDic,kCGImagePropertyGIFDelayTime);

*unclampedDelay: 延迟时间？？

NSNumber * unclampedDelay =CFDictionaryGetValue(gifDic,kCGImagePropertyGIFUnclampedDelayTime);

//////注：本人不是做美术的，不懂gif原理，但经过我试验， DelayTime和UnclampedDelayTime应该是取UnclampedDelayTime做出来的图才和用浏览器打开的时间相同

NSTimer *timer = [NSTimerscheduledTimerWithTimeInterval:delay.floatValuetarget:selfselector:@selector(play)userInfo:nilrepeats:YES];

[timerfire];

CFRelease(gifprops);

CFRelease(gif);

}

-(void)play

{

index ++;

index = index%count;

CGImageRef ref = CGImageSourceCreateImageAtIndex(gif, index, (CFDictionaryRef)gifProperties);

self.layer.contents = (id)ref;

CFRelease(ref);

}

-(void)removeFromSuperview

{

NSLog(@"removeFromSuperview");

[timer invalidate];

timer =nil;

[superremoveFromSuperview];

}

- (void)dealloc {

NSLog(@"dealloc");

CFRelease(gif);

[gifProperties release];

[superdealloc];

}

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