ios 从网络下载图片，保存，并用imageview从保存中显示

-(UIImage *) getImageFromURL:(NSString *)fileURL {    NSLog(@"执行图片下载函数");    UIImage * result;                                                                                                     NSData * data = [NSData dataWithContentsOfURL:[NSURL URLWithString:fileURL]];    result = [UIImage imageWithData:data];                                                                      return result;                                                                                                                 }

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-(void) saveImage:(UIImage *)image withFileName:(NSString *)imageName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath {                                if([[extension lowercaseString] isEqualToString:@"png"]) {        [UIImagePNGRepresentation(image) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName,@"png"]] options:NSAtomicWrite error:nil];                         }elseif([[extension lowercaseString] isEqualToString:@"jpg"] || [[extension lowercaseString] isEqualToString:@"jpeg"]) {        [UIImageJPEGRepresentation(image,1.0) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName,@"jpg"]] options:NSAtomicWrite error:nil];                           }else{//ALog(@"Image Save Failed\nExtension: (%@) is not recognized, use (PNG/JPG)", extension);NSLog(@"文件后缀不认识");    }}

-(UIImage *) loadImage:(NSString *)fileName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath {                                                                      UIImage * result = [UIImage imageWithContentsOfFile:[NSString stringWithFormat:@"%@/%@.%@", directoryPath, fileName, extension]];                  return   result;} 

把已经下载的jpg用imageview显示

NSString *documentsDirectory2 = [path2 objectAtIndex:0];//path数组里貌似只有一个元素//字符串拼接得到文件完整路径NSString *filestr =@"/MyImage.jpg";    NSString *newstr = [documentsDirectory2 stringByAppendingString:filestr];    NSLog(@"完整路径是:%@",newstr);        NSData *dd = [NSData dataWithContentsOfFile:newstr];    [img222 setImage:[UIImage imageWithData:dd]];