Question

我创建了一个应用程序，可以从任何大小的url下载文件。我的页面中有一个按钮和一个进度视图。我想点击按钮下载的文件，并在进度视图中显示下载状态。

我可以使用此代码下载任何文件，但我不知道如何使用此代码使用进度视图：

- (IBAction)Download:(id)sender
{
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        NSLog(@"Downloading Started");
        NSString *urlToDownload = @"http://192.168.1.100/emma/Adele%20-%20Someone%20Like%20You%20(MTV%20Video%20Music%20Awards%202011)%20HD%20Live.mkv";
        NSURL *url = [NSURL URLWithString:urlToDownload];
        NSData *urlData = [NSData dataWithContentsOfURL:url];
        if ( urlData )
        {
            NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
            NSString *documentsDirectory = [paths objectAtIndex:0];

            NSString *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory,@"filename.mkv"];
            dispatch_async(dispatch_get_main_queue(), ^{
                [urlData writeToFile:filePath atomically:YES];
                NSLog(@"File Saved !");
            });
            x = 1;
            NSLog(@"x : %d",x);
        }

    });
}

请指导我。

Answer 1

在.h文件中定义 NSTimer *计时器，并在 .xib

中设置 ProgressView

- (IBAction)Download:(id)sender
{
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        NSLog(@"Downloading Started");
        NSString *urlToDownload = @"http://192.168.1.100/emma/Adele%20-%20Someone%20Like%20You%20(MTV%20Video%20Music%20Awards%202011)%20HD%20Live.mkv";
        NSURL *url = [NSURL URLWithString:urlToDownload];
        NSData *urlData = [NSData dataWithContentsOfURL:url];
        if ( urlData )
        {
            NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
            NSString *documentsDirectory = [paths objectAtIndex:0];

            NSString *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory,@"filename.mkv"];

            timer = [NSTimer timerWithTimeInterval:0.5 target:self selector:@selector(updateProgressView) userInfo:nil repeats:YES];
            [timer fire];


            dispatch_async(dispatch_get_main_queue(), ^{
                [urlData writeToFile:filePath atomically:YES];
                NSLog(@"File Saved !");
            });
            x = 1;
            NSLog(@"x : %d",x);
        }

    });
}

并添加此方法

- (void) updateProgressView{
    NSString *urlToDownload = @"http://192.168.1.100/emma/Adele%20-%20Someone%20Like%20You%20(MTV%20Video%20Music%20Awards%202011)%20HD%20Live.mkv";
    NSURL *url = [NSURL URLWithString:urlToDownload];
    NSData *urlData = [NSData dataWithContentsOfURL:url];

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSString *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory,@"filename.mkv"];
    NSData *writtenData = [NSData dataWithContentsOfFile:filePath];

    float progress = [writtenData length]/(float)[urlData length];
    [progressView setProgress:progress];
    if (progress == 1.0){
         [timer invalidate];
    }
}

如何在xcode中使用Progress View来显示下载状态

1 个答案: