UWP中相机功能的定时器

Question

我目前正在开发一个UWP应用程序，我的程序中有一个摄像头功能。但是，我希望为该功能实现计时器。

我希望允许用户在侧面选择他们的首选时间，然后点击＆＃34;拍照＆＃34;按钮和在相机屏幕上它将显示一个计时器和onclick下的事件为＆＃34;拍照＆＃34;按钮将根据用户的选择而延迟。

这是我的代码来自.xaml：

<CaptureElement Name="PreviewControl" Margin="566,77,166,50"/>
<Button x:Name="PhotoButton" Content="Take a picture!" HorizontalAlignment="Left" Margin="990,678,0,-91" VerticalAlignment="Top" Click="PhotoButton_Click" Height="45" Width="313" Background="White" Foreground="Black"/>

//Timer buttons  
<Button x:Name="Timer_3sec" Content="3 seconds" HorizontalAlignment="Left" Margin="138,125,0,0" VerticalAlignment="Top" Height="66" Width="262" Background="White" Foreground="Black"/>
<Button x:Name="Timer_5sec" Content="5 seconds" HorizontalAlignment="Left" Margin="138,234,0,0" VerticalAlignment="Top" Height="66" Width="262" Background="White" Foreground="Black"/>
<Button x:Name="Timer_7sec" Content="7 seconds" HorizontalAlignment="Left" Margin="138,337,0,0" VerticalAlignment="Top" Height="66" Width="262" Background="White" Foreground="Black"/>

来自xaml.cs的代码：

private async void PhotoButton_Click(object sender, RoutedEventArgs e)
    {
        await TakePhotoAsync();
    }

private async Task TakePhotoAsync()
    {

        var stream = new InMemoryRandomAccessStream();

        Debug.WriteLine("Taking photo...");
        await _mediaCapture.CapturePhotoToStreamAsync(ImageEncodingProperties.CreateJpeg(), stream);

        try
        {
            var file = await _captureFolder.CreateFileAsync("SimplePhoto.jpg", CreationCollisionOption.GenerateUniqueName);
            Debug.WriteLine("Photo taken! Saving to " + file.Path);

            var photoOrientation = CameraRotationHelper.ConvertSimpleOrientationToPhotoOrientation(_rotationHelper.GetCameraCaptureOrientation());

            await ReencodeAndSavePhotoAsync(stream, file, photoOrientation);
            Debug.WriteLine("Photo saved!");

            await Helpers.MessageDialogHelpers.ShowNoActionMessageBox("Your photo has been taken!", "");


        }
        catch (Exception ex)
        {
            // File I/O errors are reported as exceptions
            Debug.WriteLine("Exception when taking a photo: " + ex.ToString());
        }

    }

Answer 1

在代码后面创建一个字段：

private int _seconds;

在按钮处理程序中设置适当的时间：

private void Timer_3sec_Click(object sender, RoutedEventArgs e)
{
    _seconds = 3;
}

将延迟添加到照片按钮处理程序：

private async void PhotoButton_Click(object sender, RoutedEventArgs e)
{
    await Task.Delay(TimeSpan.FromSeconds(_seconds));
    await TakePhotoAsync();
}

这应该足够了。如果您发现后面的代码变得复杂，因为您要添加所有逻辑，那么请尝试阅读有关MVVM的内容。