(iPhone/iPad)文件上传与下载

文件下载：

-(void)downLoadImages: (NSString *)url saveAsImagesName:(NSString *)name{ ASIHTTPRequest *request; request = [[[ASIHTTPRequest alloc] initWithURL:[NSURL URLWithString:url]]autorelease]; [request setDownloadDestinationPath:[[NSHomeDirectory()stringByAppendingPathComponent:@"Documents"]stringByAppendingPathComponent:name]]; [request setNumberOfTimesToRetryOnTimeout:2 ]; [request startSynchronous]; NSError *error = [request error]; if (!error) { UIImage *img = [UIImage imageWithContentsOfFile:[request downloadDestinationPath]]; if (img) { [imgPerson setImage:img]; } }else{ UIAlertView *alert=[[UIAlertView alloc]initWithTitle:nil message:@"连接失败!请检查网络连接或服务是否正常！" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil]; [alert show]; [alert release]; } }
其中：第一个参数url是文件下载地址，第二个参数name是文件保存到本地的文件名。

文件上传：

//图片上传 - (void)uploadImage { NSData *imageData = UIImagePNGRepresentation(imgPerson.image); // setting up the URL to post to NSString *urlString = @"http://www.xxxx.com/lsmobile/UploadServlet"; // setting up the request object now NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease]; [request setURL:[NSURL URLWithString:urlString]]; [request setHTTPMethod:@"POST"]; /* add some header info now we always need a boundary when we post a file also we need to set the content type You might want to generate a random boundary.. this is just the same as my output from wireshark on a valid html post */ NSString *boundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"]; NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary]; [request addValue:contentType forHTTPHeaderField: @"Content-Type"]; /* now lets create the body of the post */ NSMutableData *body = [NSMutableData data]; [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"userfile\"; filename=\"%@\"\r\n",strHeadPath] dataUsingEncoding:NSUTF8StringEncoding]]; [strHeadPath release]; strHeadPath=nil; [body appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[NSData dataWithData:imageData]]; [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]]; // setting the body of the post to the reqeust [request setHTTPBody:body]; NSError *errorMsg=nil; // now lets make the connection to the web NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:&errorMsg]; if (!errorMsg) { NSString *returnString = [[[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding] autorelease]; NSLog(returnString); if ([returnString isEqualToString:@"Fail"]) { UIAlertView *alert=[[UIAlertView alloc]initWithTitle:nil message:@"sorry，图片上传失败，请尝试重新提交" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil]; [alert show]; [alert release]; }else{ strImgPath=[[NSString alloc] initWithFormat:@"%@",returnString];//在更改操作中release uploadFlg=true; } [returnString release]; returnString=nil; }else{ UIAlertView *alert=[[UIAlertView alloc]initWithTitle:nil message:@"连接失败!请检查网络连接或服务是否正常！" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil]; [alert show]; [alert release]; } }本段代码中上传的是图片，如果想上传其他文件，可更改最初的NSData数据源。

还有很多方法

更多上传下载方法可参考：

1.iOS开发之结合asp.net webservice实现文件上传下载http://www.cnblogs.com/zhuqil/archive/2011/07/30/2122019.html

2.http://www.flyblog.info/catprogramming/392.html

3.http://iphone.zcentric.com/2008/08/29/post-a-uiimage-to-the-web/

4.http://zcentric.com/2008/08/29/post-a-uiimage-to-the-web/