iOS-微信分享多张图片（UIActivityViewController多图分享和多图分享失败）

前言

微信分享到朋友圈，可分享的类型有：文字类型、图片类型、音乐类型、视频类型和网页类型，但是我们在做图片分享的时候发现微信给的API只能分享一张图片，达不到一些APP的需求，而产品汪或者Boss想要分享多张图片，比如前段时间我做的一个APP，是电商类APP，想把商品的图片都分享到朋友圈，查看微信的API根本没有提供API，在这里我们只能用iOS系统自带的分享了。

UIActivityViewController

UIActivityViewController是在iOS 6开始支持的，同样是不能在Apple TV的开发中使用。而且UIActivityViewController是直接继承UIViewController的，这意味着我们需要自己来展示和解散视图。

主要代码

OC代码

<span style="font-size:18px;">UIImage *imageToShare = [UIImage imageNamed:@"99687078.jpg"];
    UIImage *imageToShare1 = [UIImage imageNamed:@"2222.jpg"];
    NSArray *activityItems = @[imageToShare,imageToShare1];
    UIActivityViewController *activityVC = [[UIActivityViewController alloc]initWithActivityItems:activityItems applicationActivities:nil];
    [self presentViewController:activityVC animated:TRUE completion:nil];</span>

swift代码

<span style="font-size:18px;">let imageToShare1 = UIImage.init(named: "99687078.jpg")
        let imageToShare2 = UIImage.init(named: "2222.jpg")
        let activityItems = [imageToShare1,imageToShare2]
        let activityVC = UIActivityViewController.init(activityItems: activityItems, applicationActivities: nil)
        self.present(activityVC, animated: true, completion: nil)</span>

运行截图

注意

我们在分享多张图片到朋友圈的时候会发现，我们在不做任何处理的时候，直接从手机相册调取多张图片分享的时候，分享失败。具体什么原因我研究了一下，发现分享的数据总共大小有限制；在这里举个例子，比如电梯，电梯限定的重量是固定的，所以不管你乘坐多少人，乘坐的人比较胖，那就乘坐的人比较少，如果乘坐的人比较瘦，那就可以多坐几个；所以UIActivityViewController分享多张图片到朋友圈的时候，我根据图片数量的多少，然后把图片压缩到指定宽高，比如一张图片，我就压缩成和微信压缩图片一样的大小1280，如果9张我就压缩成500；

代码

压缩图片的方法在下面粘出，其中compressibilityFactor为图片宽高的最大值；

<span style="font-size:18px;">#import "WeChatJPEGImager.h"

#define KCompressibilityFactor 1280.00

@implementation WeChatJPEGImager

#pragma mark - 压缩一张图片 最大宽高1280 类似于微信算法
- (UIImage *)getJPEGImagerImg:(UIImage *)image{
    CGFloat oldImg_WID = image.size.width;
    CGFloat oldImg_HEI = image.size.height;
    //CGFloat aspectRatio = oldImg_WID/oldImg_HEI;//宽高比
    if(oldImg_WID > KCompressibilityFactor || oldImg_HEI > KCompressibilityFactor){
        //超过设置的最大宽度 先判断那个边最长
        if(oldImg_WID > oldImg_HEI){
            //宽度大于高度
            oldImg_HEI = (KCompressibilityFactor * oldImg_HEI)/oldImg_WID;
            oldImg_WID = KCompressibilityFactor;
        }else{
            oldImg_WID = (KCompressibilityFactor * oldImg_WID)/oldImg_HEI;
            oldImg_HEI = KCompressibilityFactor;
        }
    }
    UIImage *newImg = [self imageWithImage:image scaledToSize:CGSizeMake(oldImg_WID, oldImg_HEI)];
    NSData *dJpeg = nil;
    if (UIImagePNGRepresentation(newImg)==nil) {
        dJpeg = UIImageJPEGRepresentation(newImg, 0.5);
    }else{
        dJpeg = UIImagePNGRepresentation(newImg);
    }
    return [UIImage imageWithData:dJpeg];
}
#pragma mark - 压缩多张图片 最大宽高1280 类似于微信算法
- (NSArray *)getJPEGImagerImgArr:(NSArray *)imageArr{
    NSMutableArray *newImgArr = [NSMutableArray new];
    for (int i = 0; i<imageArr.count; i++) {
        UIImage *newImg = [self getJPEGImagerImg:imageArr[i]];
        [newImgArr addObject:newImg];
    }
    return newImgArr;
}
#pragma mark - 压缩一张图片 自定义最大宽高
- (UIImage *)getJPEGImagerImg:(UIImage *)image compressibilityFactor:(CGFloat)compressibilityFactor{
    CGFloat oldImg_WID = image.size.width;
    CGFloat oldImg_HEI = image.size.height;
    //CGFloat aspectRatio = oldImg_WID/oldImg_HEI;//宽高比
    if(oldImg_WID > compressibilityFactor || oldImg_HEI > compressibilityFactor){
        //超过设置的最大宽度 先判断那个边最长
        if(oldImg_WID > oldImg_HEI){
            //宽度大于高度
            oldImg_HEI = (compressibilityFactor * oldImg_HEI)/oldImg_WID;
            oldImg_WID = compressibilityFactor;
        }else{
            oldImg_WID = (compressibilityFactor * oldImg_WID)/oldImg_HEI;
            oldImg_HEI = compressibilityFactor;
        }
    }
    UIImage *newImg = [self imageWithImage:image scaledToSize:CGSizeMake(oldImg_WID, oldImg_HEI)];
    NSData *dJpeg = nil;
    if (UIImagePNGRepresentation(newImg)==nil) {
        dJpeg = UIImageJPEGRepresentation(newImg, 0.5);
    }else{
        dJpeg = UIImagePNGRepresentation(newImg);
    }
    return [UIImage imageWithData:dJpeg];
}
#pragma mark - 压缩多张图片 自定义最大宽高
- (NSArray *)getJPEGImagerImgArr:(NSArray *)imageArr compressibilityFactor:(CGFloat)compressibilityFactor{
    NSMutableArray *newImgArr = [NSMutableArray new];
    for (int i = 0; i<imageArr.count; i++) {
        UIImage *newImg = [self getJPEGImagerImg:imageArr[i] compressibilityFactor:compressibilityFactor];
        [newImgArr addObject:newImg];
    }
    return newImgArr;
}
#pragma mark - 根据宽高压缩图片
- (UIImage *)imageWithImage:(UIImage *)image scaledToSize:(CGSize)newSize{
    UIGraphicsBeginImageContext(newSize);
    [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}</span>

Demo下载地址

http://download.csdn.net/detail/u014220518/9702030

相关阅读

iOS-微信朋友圈图片压缩算法

http://blog.csdn.NET/u014220518/article/details/58136932

来源：http://blog.csdn.net/u014220518/article/details/53465631