好久没写了，今天写个iOS用ASIFormDataRequest实现图片上传

方法一：表单提交

NSString *fileName = [[NSBundle mainBundle] pathForResource:@"imageName" ofType:@"png"];//获取图片在本地的地址
    ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL: [NSURL URLWithString: url]];
    [request setFile:fileName forKey:@"image"];
    [request setDelegate:delegate];
    [request setTimeOutSeconds:TIME_OUT_SECONDS];
    [request startAsynchronous];

方法二：POST:

/*
 ios中获取图片的方法有两种，一种是UIImageJPEGRepresentation(image,0-1之间的压缩比例)，一种是UIImagePNGRepresentation(直接放UIImage)
 前者获取到图片的数据量要比后者的小很多。。
*/
    UIImage *im = [UIImage imageNamed:@"imageName"];//通过path图片路径获取图片
    NSData *data = UIImagePNGRepresentation(im);//获取图片数据
       
    NSMutableData *imageData = [NSMutableData dataWithData:data];//ASIFormDataRequest 的setPostBody 方法需求的为NSMutableData类型
    ASIFormDataRequest *aRequest = [[ASIFormDataRequest alloc] initWithURL:[NSURL URLWithString:url]];
    [aRequest setDelegate:delegate];//代理
    [aRequest setRequestMethod:@"POST"];
    
    [aRequest setPostBody:imageData];
    [aRequest addRequestHeader:@"Content-Type" value:@"image/png"];//这里的value值 需与服务器端 一致
    
    [aRequest startAsynchronous];//开始。异步

    [aRequest setDidFinishSelector:@selector(headPortraitSuccess)];//当成功后会自动触发 headPortraitSuccess 方法
    [aRequest setDidFailSelector:@selector(headPortraitFail)];//如果失败会 自动触发 headPortraitFail 方法