iOS之SDWebimage下载图片链接带中文处理

图片连接存到了一个数组中，下载一张添加一张。但是发现有时候只显示占位图不显示图片，刚开始以为是网络慢，下载需要一段时间，但是等了好久仍然没有。打断点查看了一下，原来是因为图片链接包含中文，这样的话下载不成功了。于是用NSUTF8将字符串进行编辑，然后再去下载便可以了。

NSString * imageUrl = [imageUrl1 stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

全部代码如下：

- (void)addImage:(NSArray *)imageUrlArr{
    for (NSString *imageUrl1 in imageUrlArr) {

        NSString * imageUrl = [imageUrl1 stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
        UIImage *newImage = [[SDImageCache sharedImageCache] imageFromDiskCacheForKey:imageUrl];//用地址去本地找图片
        if (newImage != nil) {//如果本地有
            // newImage就是图片
            [_imageMuarr addObject:newImage];
            [self raloadImage];
        } else {//如果本地没有
            //下载图片
            [[SDWebImageManager sharedManager] downloadImageWithURL:[NSURL URLWithString:imageUrl] options:0 progress:^(NSInteger receivedSize, NSInteger expectedSize) {
                //这里是处理下载进度的,好像没必要管他
            } completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished, NSURL *imageURL) {
                if (image) {//下载完成后
                    //同上处理
                    [_imageMuarr addObject:image];
                    [self raloadImage];
                }
            }];
        }
    }
}

- (void)raloadImage{
    _myScrollView.backgroundColor = [UIColor clearColor];//去掉预设图片,也就是背景
    UIImage *image = [_imageMuarr lastObject];//取数组的最后一个元素
    CGFloat width = 110.0 /image.size.height *image.size.width;

    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake((_imageMuarr.count -1) *10.0 +_imageTotalWidth, 0, width, 110)];
    imageView.userInteractionEnabled = YES;
    imageView.image = image;
    [_myScrollView addSubview:imageView];
    _imageTotalWidth += width;
    _myScrollView.contentSize = CGSizeMake((_imageMuarr.count -1) *10.0 +_imageTotalWidth, 110);

    imageView.tag = _imageMuarr.count-1;
    UITapGestureRecognizer * singleRecognizerImageView = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(imageViewSingleTapFrom:)];
    [imageView addGestureRecognizer:singleRecognizerImageView];
}

网上查的还有一个方法是

NSString *encodedString = (NSString *)
CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
(CFStringRef)urlString,
(CFStringRef)@"!$&'()*+,-./:;=?@_~%#[]",
NULL,kCFStringEncodingUTF8);

UTF-8解码

NSString* str= [@"%E4%B8%AD%E5%9B%BD" stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];  
    NSLog(@"strAfterDecodeByUTF8AndURI=%@", str);    

UTF-8转码

[@"我是中文" stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];  

URL编码

/**
 *
 *  此方法由一个UTF8字符串生成一个url编码(DOS状态下中文编码)字符串
 *  @return 一个url编码字符串
 *
 */

+(NSString *)getUrlStringFromString:(NSString *)urlStr{  
    NSString *outputStr = (__bridge NSString *)  
    CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,  
                                            (__bridge CFStringRef)urlStr,  
                                            NULL,  
                                            (CFStringRef)@"!*'();:@&=+$,/?%#[]",  
                                            kCFStringEncodingUTF8);  
    return outputStr;  
} 

URL解码

+ (NSString *)decodeFromPercentEscapeString: (NSString *) urlStr  
{  
    NSMutableString *outputStr = [NSMutableString stringWithString:urlStr];  
    [outputStr replaceOccurrencesOfString:@"+"  
                               withString:@""  
                                  options:NSLiteralSearch  
                                    range:NSMakeRange(0,  
                                                      [outputStr length])];  
      
    return [outputStr stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];  
}