C＃的Windows 8商店（地铁，WinRT的）字节数组的BitmapImage [英] C# Windows 8 Store (Metro, WinRT) Byte array to BitmapImage

问题描述

我的工作适用过滤器，以图像的Windows 8地铁应用程序。我有应用程序的Web版本，并希望将它移植。但是，正如我们都知道的WinRT不具备一切美好的事物.NET另有规定：/

I am working on a Windows 8 Metro app that applies filters to images. I have a web version of the app and wanted to port it. But as we all know WinRT doesn't have all the good things .NET provides otherwise :/

目前，我一个字节数组上应用过滤器，我想保留这样的说法，因为它是超级快！所以这几天我一直在寻找方法来转换StorageFile为byte []，然后到BitmapImage的字节[]。

Currently I am applying the filters on a byte array and I want to keep it that way, because it's super fast! So for the past few days I have been searching for ways to convert a StorageFile to byte[] and then byte[] to BitmapImage.

到目前为止，我已经能够做到第一个（StorageFile为byte []）。下面是我如何做到这一点：

So far I have managed to do the first one (StorageFile to byte[]). Here is how I do it:

public async Task<Byte[]> ImageFileToByteArray(StorageFile file)
    {
        IRandomAccessStream stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
        BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream);
        PixelDataProvider pixelData = await decoder.GetPixelDataAsync();
        return pixelData.DetachPixelData();
    }

这一段代码返回字节[] 包含的像素数据为BGRA。

This piece of code returns a byte[] that contains the pixel data as BGRA.

和来这里的棘手的部分。我不能字节数组成功地转换成的BitmapImage。我已经找遍了的地方和许多人建议使用WriteableBitmap的，但这并不做很多对我好。我还发现了应工作的代码一些作品......但他们不这样做。

And here comes the tricky part. I cannot successfully convert the byte array into a BitmapImage. I have searched all over the places and many people suggest using WriteableBitmap but that doesn't do much good to me. I have also found some pieces of code that should be working... but they don't.

一个我已经使用InMemoryRandomAccessStream这样的尝试的解决方案：

One of the solutions I have tried is using InMemoryRandomAccessStream like this:

public async Task<BitmapImage> ByteArrayToBitmapImage(Byte[] pixels)
    {
        var stream = new InMemoryRandomAccessStream();
        await stream.WriteAsync(pixels.AsBuffer());
        stream.Seek(0);
        var image = new BitmapImage();
        await image.SetSourceAsync(stream);
        return image;
    }

这之一抛出以下异常：

类型的异常'System.Exception的'发生在mscorlib.dll，但在用户代码中没有处理

An exception of type 'System.Exception' occurred in mscorlib.dll but was not handled in user code

其他信息：组件无法找到。 （从HRESULT异常：0x88982F50）

Additional information: The component cannot be found. (Exception from HRESULT: 0x88982F50)

我试着用这条线来代替：

I tried using this line instead:

PixelDataProvider pixelData = await decoder.GetPixelDataAsync(
            BitmapPixelFormat.Bgra8, 
            BitmapAlphaMode.Ignore, 
            new BitmapTransform(),
            ExifOrientationMode.IgnoreExifOrientation, 
            ColorManagementMode.DoNotColorManage);

但它确实我没有好，因为我不断收到这个异常。

But it did me no good since I keep getting that exception.

我也试过这样的：

var bitmapImage = new BitmapImage();
        var pixels = await ImageFileToByteArray(file);
        ImageSource imgSource;
        using (InMemoryRandomAccessStream ms = new InMemoryRandomAccessStream())
        {
            using (DataWriter writer = new DataWriter(ms.GetOutputStreamAt(0)))
            {
                writer.WriteBytes(pixels);
                await writer.StoreAsync();
            }

            await bitmapImage.SetSourceAsync(ms);
            imgSource = bitmapImage;
        }

和获得相同的异常的第一段代码。

And get the same exception as the first piece of code.

我也试过，包括使用正常流，然后转换成IRandomAccessStream几个其他的方式，但他们也不能工作。

I have also tried several other ways that include using a normal Stream then converting into a IRandomAccessStream but they didn't work either.

所有上面的代码似乎没什么问题。所以，我此刻的猜测是，这个问题是在字节[] 。我猜的PixelData取出的格式里面是无效的，所以我试图将其更改为RGBA但这并没有帮助。另外，PixelHeight和BitmapImage的的PixelWidth为0。

All of the above code seems fine to me. So my guess at the moment is that the problem is in the byte[]. I'm guessing that the format of the pixelData inside is not valid, so I tried changing it to RGBA but that didn't help either. Also the PixelHeight and PixelWidth of the BitmapImage are 0.

推荐答案

这是为我工作，

    private async Task<BitmapImage> ByteArrayToBitmapImage(byte[] byteArray)
    {
        var bitmapImage = new BitmapImage();

        var stream = new InMemoryRandomAccessStream();
        await stream.WriteAsync(byteArray.AsBuffer());
        stream.Seek(0);

        bitmapImage.SetSource(stream);
        return bitmapImage;
    }

这篇关于C＃的Windows 8商店（地铁，WinRT的）字节数组的BitmapImage的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！