Question

我想确定正在下载的文件的fileSize。我使用ASIHTTPRequest，通常它应该跳转到didReceiveBytes但不是这样，而是我启动一个反复检查该位置的文件大小的计时器。像这样：

NSError* error;
NSFileManager* fm = [NSFileManager defaultManager];
NSDictionary* itemAttributes = [fm attributesOfItemAtPath:_location error:&error];
if(!error){
    unsigned long long fsize = [itemAttributes fileSize];
    [downloadLabel setText:[NSString stringWithFormat:@"%llu MB downloaded",fsize] ];
    NSLog(@"MB downloaded: %llu", fsize);
} else {
    NSLog(@"error=%@", error);
}

问题是，在文件完成下载之前，我得到以下错误：

  error=Error Domain=NSCocoaErrorDomain Code=260 "The operation couldn’t be completed.             (Cocoa error 260.)" UserInfo=0xf57aa60 {NSFilePath= "long filename", NSUnderlyingError=0xf57ad90 "The operation couldn’t be completed. No such file or directory"

完成后它终于给了我：

MB下载：34443951

事实上，我最终下载的MB告诉我文件路径是正确的。但为什么它在下载时告诉我该文件不存在？我该如何解决这个问题？

Answer 1

使用ASIHTTP lib进行网络，您可以轻松完成。

阅读“自定义进度跟踪”部分。

或者您可以使用

-(NSURLRequest *)connection:(NSURLConnection *)connection
        willSendRequest:(NSURLRequest *)request
       redirectResponse:(NSURLResponse *)response {
}

long long size = [response expectedContentLength];

但是在这样的网站上有很多解决方案：
http://goo.gl/0hrK2

Answer 2

最后，我最终直接从ASIHTTP请求中询问字节：

unsigned long long bytes = request.totalBytesRead;
double mb;
if(bytes >0){
    mb = bytes/1000000.0f;        
    [downloadLabel setText:[NSString stringWithFormat:@"%.2f MB downloaded",mb] ];
}

使用触发的计时器连续检索此值以更新下载的字节并转换为表示MB。

Answer 3

试试这段代码，它可以帮到你

- (void)request:(ASIHTTPRequest *)request didReceiveData:(NSData *)data
{

    [request contentLength];
    [downloadButtton setTitle:@"Cancel" forState:UIControlStateNormal];
    [downloadButtton addTarget:self action:@selector(cancelDownloading) forControlEvents:UIControlEventTouchUpInside];
    long length = [request contentLength];

    fileLength = length;

    NSLog(@"fileLength ====> %f",fileLength);


  //  progressView.hidden=NO;
   // progressText.hidden=NO;
    double length2 = [data length];
    currentLength += length2;
    //    double progress = currentLength/fileLength;



  NSString *firstDataLength=[NSString stringWithFormat:@"%.2f MB",fileLength/1024/1024 ];
   NSString *totalMBytes=[NSString stringWithFormat:@" of %.2f MB",fileLength/1024/1024 ];
   NSString *totalMBytesWritten=[NSString stringWithFormat:@"%.2f MB",currentLength/1024/1024];


    NSLog(@"firstDataLength %@",firstDataLength);
    NSLog(@"totalMBytes %@",totalMBytes);
    NSLog(@"totalMBytesWritten %@",totalMBytesWritten);



    progressText.text=[totalMBytesWritten stringByAppendingString:totalMBytes];
    NSUInteger left = [data length];
    NSUInteger nwr = 0;
    do {
        nwr = [fileStreem write:[data bytes] maxLength:left];
        if (-1 == nwr) break;
        left -= nwr;
    } while (left > 0);
    if (left) {
        NSLog(@"stream error: %@", [fileStreem streamError]);
    }


}

下载时确定文件大小

3 个答案: