我可以转换成图像/位图WriteableBitmap的？ [英] Can I convert image/bitmap to writeablebitmap?

问题描述

我有两个我想合并到一起的位图图像。我发现，我能做到这一点与WriteableBitmap的，但我怎么先转换这些图片writeablebitmaps

I have two bitmap images that i would like to merge together. I found that I can do that with writeablebitmap but how do I first convert these images to writeablebitmaps?

更新：我找不到了方式位图转换为可写的位图直接让我做的事是写我的位图在独立存储和流对象读一遍。其中后Xyroid下面给出的代码可用于合并图像和合并后的图像转换为位图。

UPDATE: I could not find out a way to convert bitmaps to writeable bitmap directly so what I did was to write my bitmap in isolated storage and read it again in a stream object. After which the code given below by Xyroid can be used to merge the images and convert the merged image to bitmap.

推荐答案

下面我我给你的代码合并两个图像。 WinRT中的WriteableBitmap的不同的是，它的构造函数的高度和宽度作为参数。我已经使用 WriteableBitmapEx 一些功能。

Here I am giving you the code to merge two images. WinRT's WriteableBitmap is different, the constructor of it takes height and width as argument. I have used WriteableBitmapEx for some functions.

XAML

<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
    <Grid.ColumnDefinitions>
        <ColumnDefinition />
        <ColumnDefinition />
    </Grid.ColumnDefinitions>
    <Canvas x:Name="BaseCanvas" Width="683" Height="768">
        <Image Source="Assets/img1.png" />
        <Image Source="Assets/img2.png" Canvas.Top="308" />
    </Canvas>
    <Image x:Name="imgTarget" Grid.Column="1" Stretch="None"/>
</Grid>

C＃

C#

protected async override void OnNavigatedTo(NavigationEventArgs e)
{
    StorageFile destiFile = await ApplicationData.Current.TemporaryFolder.CreateFileAsync("Merged.png", CreationCollisionOption.ReplaceExisting);

    WriteableBitmap wb;

    wb = await Render();

    using (IRandomAccessStream stream = await destiFile.OpenAsync(FileAccessMode.ReadWrite))
    {
        BitmapEncoder encoder = await BitmapEncoder.CreateAsync(
            BitmapEncoder.PngEncoderId, stream);
        Stream pixelStream = wb.PixelBuffer.AsStream();
        byte[] pixels = new byte[pixelStream.Length];
        await pixelStream.ReadAsync(pixels, 0, pixels.Length);

        encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Ignore,
            (uint)wb.PixelWidth, (uint)wb.PixelHeight, 96.0, 96.0, pixels);
        await encoder.FlushAsync();
    }

    var bitmp = new BitmapImage();
    using (var strm = await destiFile.OpenReadAsync())
    {
        bitmp.SetSource(strm);
        imgTarget.Source = bitmp;
    }
}

private async Task<WriteableBitmap> Render()
{
    var Assets = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFolderAsync("Assets");

    StorageFile file1 = await Assets.GetFileAsync("img1.png");
    StorageFile file2 = await Assets.GetFileAsync("img2.png");

    BitmapImage i1 = new BitmapImage();
    BitmapImage i2 = new BitmapImage();

    using (IRandomAccessStream strm = await file1.OpenReadAsync())
    {
        i1.SetSource(strm);
    }

    using (IRandomAccessStream strm = await file2.OpenReadAsync())
    {
        i2.SetSource(strm);
    }

    WriteableBitmap img1 = new WriteableBitmap(i1.PixelWidth, i1.PixelHeight);
    WriteableBitmap img2 = new WriteableBitmap(i2.PixelWidth, i2.PixelHeight);
    using (IRandomAccessStream strm = await file1.OpenReadAsync())
    {
        img1.SetSource(strm);
    }

    using (IRandomAccessStream strm = await file2.OpenReadAsync())
    {
        img2.SetSource(strm);
    }


    WriteableBitmap destination = new WriteableBitmap((int)(img1.PixelWidth > img2.PixelWidth ? img1.PixelWidth : img2.PixelWidth), (int)(img1.PixelHeight + img1.PixelHeight));
    destination.Clear(Colors.White);
    destination.Blit(new Rect(0, 0, (int)img1.PixelWidth, (int)img1.PixelHeight),img1,new Rect(0, 0, (int)img1.PixelWidth, (int)img1.PixelHeight));
    destination.Blit(new Rect(0, (int)img1.PixelHeight, (int)img2.PixelWidth, (int)img2.PixelHeight), img2, new Rect(0, 0, (int)img2.PixelWidth, (int)img2.PixelHeight));
    return destination;
}

请注意，您必须添加 System.Runtime。 InteropServices.WindowsRuntime 命名空间。

Please note you have to add System.Runtime.InteropServices.WindowsRuntime namespace.

更新1

假设，如果你已经两个的BitmapImage IMG1 和 IMG2 ，然后做这样的

Suppose if you have already two BitmapImage img1 and img2, then do like this

protected async override void OnNavigatedTo(NavigationEventArgs e)
{
    StorageFile destiFile = await ApplicationData.Current.TemporaryFolder.CreateFileAsync("Merged.png", CreationCollisionOption.ReplaceExisting);

    WriteableBitmap wb;

    wb = await Render();

    using (IRandomAccessStream stream = await destiFile.OpenAsync(FileAccessMode.ReadWrite))
    {
        BitmapEncoder encoder = await BitmapEncoder.CreateAsync(
            BitmapEncoder.PngEncoderId, stream);
        Stream pixelStream = wb.PixelBuffer.AsStream();
        byte[] pixels = new byte[pixelStream.Length];
        await pixelStream.ReadAsync(pixels, 0, pixels.Length);

        encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Ignore,
            (uint)wb.PixelWidth, (uint)wb.PixelHeight, 96.0, 96.0, pixels);
        await encoder.FlushAsync();
    }

    var bitmp = new BitmapImage();
    using (var strm = await destiFile.OpenReadAsync())
    {
        bitmp.SetSource(strm);
        imgTarget.Source = bitmp;
    }
}

private async Task<WriteableBitmap> Render()
{  
    WriteableBitmap destination = new WriteableBitmap((int)(img1.PixelWidth > img2.PixelWidth ? img1.PixelWidth : img2.PixelWidth), (int)(img1.PixelHeight + img1.PixelHeight));
    destination.Clear(Colors.White);
    destination.Blit(new Rect(0, 0, (int)img1.PixelWidth, (int)img1.PixelHeight),img1,new Rect(0, 0, (int)img1.PixelWidth, (int)img1.PixelHeight));
    destination.Blit(new Rect(0, (int)img1.PixelHeight, (int)img2.PixelWidth, (int)img2.PixelHeight), img2, new Rect(0, 0, (int)img2.PixelWidth, (int)img2.PixelHeight));
    return destination;
}

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