iOS gif圖顯示問題

問題

有時候須要顯示gif動態圖，讓界面更加的絢麗，可是iOS默認只支持png,gpg圖片。那麼如何才能顯示gif圖呢？

解決方式

1. 添加框架

   CoreGraphics.framework

   ImageIO.framework

2. 引入SCGIFImageView類

SCGIFImageView.h

#import <UIKit/UIKit.h>

    @interface SCGIFImageFrame : NSObject {

    }
    @property (nonatomic) double duration;
    @property (nonatomic, retain) UIImage* image;

    @end

    @interface SCGIFImageView : UIImageView {
        NSInteger _currentImageIndex;
    }
    @property (nonatomic, retain) NSArray* imageFrameArray;
    @property (nonatomic, retain) NSTimer* timer;
    @property (nonatomic, assign) NSInteger sumCount;

    //Setting this value to pause or continue animation;
    @property (nonatomic) BOOL animating;

    - (void)setData:(NSData*)imageData;
    @end

SCGIFImageView.m

#import "SCGIFImageView.h"
    #import <ImageIO/ImageIO.h>

    @implementation SCGIFImageFrame
    @synthesize image = _image;
    @synthesize duration = _duration;


    @end

    @interface SCGIFImageView ()

    - (void)resetTimer;

    - (void)showNextImage;

    @end

    @implementation SCGIFImageView
    @synthesize imageFrameArray = _imageFrameArray;
    @synthesize timer = _timer;
    @synthesize animating = _animating;


    - (void)resetTimer {
        if (_timer && _timer.isValid) {
            [_timer invalidate];
        }

        self.timer = nil;
    }

    - (void)setData:(NSData *)imageData {
        if (!imageData) {
            return;
        }
        [self resetTimer];
        CGImageSourceRef source = CGImageSourceCreateWithData((CFDataRef)imageData, NULL);
size_t count = CGImageSourceGetCount(source);

        NSMutableArray* tmpArray = [NSMutableArray array];

        for (size_t i = 0; i < count; i++) {
            SCGIFImageFrame* gifImage = [[SCGIFImageFrame alloc] init];

            CGImageRef image = CGImageSourceCreateImageAtIndex(source, i, NULL);
            gifImage.image = [UIImage imageWithCGImage:image scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp];

            NSDictionary* frameProperties = CFBridgingRelease(CGImageSourceCopyPropertiesAtIndex(source, i, NULL));
            gifImage.duration = [[[frameProperties objectForKey:(NSString*)kCGImagePropertyGIFDictionary] objectForKey:(NSString*)kCGImagePropertyGIFDelayTime] doubleValue];
            gifImage.duration = MAX(gifImage.duration, 0.01);

            [tmpArray addObject:gifImage];

            CGImageRelease(image);
        }
        CFRelease(source);

        self.imageFrameArray = nil;
        if (tmpArray.count > 1) {
            self.imageFrameArray = tmpArray;
            _currentImageIndex = -1;
            _animating = YES;
            [self showNextImage];
        } else {
            self.image = [UIImage imageWithData:imageData];
        }
    }


    - (void)setImage:(UIImage *)image {
        [super setImage:image];
        [self resetTimer];
        self.imageFrameArray = nil;
        _animating = NO;
    }

    - (void)showNextImage {
        if (_sumCount > 0) {
            _animating = _sumCount - 1 == _currentImageIndex ? NO : YES;
        }
        if (!_animating) {
            return;
        }
        _currentImageIndex = (++_currentImageIndex) % _imageFrameArray.count;
        SCGIFImageFrame* gifImage = [_imageFrameArray objectAtIndex:_currentImageIndex];
        [super setImage:[gifImage image]];
        self.timer = [NSTimer scheduledTimerWithTimeInterval:gifImage.duration target:self          selector:@selector(showNextImage) userInfo:nil repeats:NO];
    }

    - (void)setAnimating:(BOOL)animating {
        if (_imageFrameArray.count < 2) {
            _animating = animating;
            return;
        }

        if (!_animating && animating) {
            //continue
            _animating = animating;
            if (!_timer) {
                [self showNextImage];
            }
        } else if (_animating && !animating) {
            //stop
            _animating = animating;
            [self resetTimer];
        }
    }

    @end

1. 添加gif圖片

   在Images.xcassets中添加須要的gif動態圖。

2. 使用方式

   • 引入頭文件SCGIFImageView.h

   • 在須要的添加的地方添加如下代碼

     NSString* filePath = [[NSBundle mainBundle] pathForResource:@"6plus_hover.gif" ofType:nil];
        NSData* imageData = [NSData dataWithContentsOfFile:filePath];
     
       SCGIFImageView* gifImageView = [[SCGIFImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 320)];
       [gifImageView setData:imageData];
       [gifImageView setSumCount:gifImageView.imageFrameArray.count];//設置只循環一次，不設置無限循環
       [self.view addSubview:gifImageView];