c# - 如何在 Windows-10 Metro 应用程序中为图像着色？

Question

我制作了灰度图像，我想对其进行着色（例如更改 HSL）。

在我在 Internet 上找到的示例中，我需要位图类，但它在 Windows-10 通用应用程序中不存在。

Answer 1

WriteableBitmap 类可用于获取图像的像素缓冲区并使用语言指定的方法修改像素内容。请查看“备注”和“示例”会话以更好地理解。

我想向您推荐WriteableBitmapEx，它包含许多 WriteableBitmap 的扩展方法。您可以在项目中安装NuGet 包以使用它。

Answer 2

经过许多错误后，这里是工作代码：

它可能看起来很糟糕，但它正在工作，我很高兴:)

private static async void changeImage(Molecule molecule)
{
    Molecule.Reaction++;    // Used as Working/Loading status here
    var atoms = molecule.Atoms;
    if (atoms > 5) atoms = 5;

    var stream = await GetStream("Assets/Images/" + atoms + ".png");
    var decoder = await BitmapDecoder.CreateAsync(stream); 
    var pixelData = await decoder.GetPixelDataAsync();
    var data = pixelData.DetachPixelData(); // Finally something where I can get my pixels

    var wb = new WriteableBitmap(16, 16);
    //wb.SetSource(stream);     // Get pixel not working so I dont need this

    for(int y = 0; y < decoder.PixelHeight; y++)
    {
        for(int x = 0; x < decoder.PixelWidth; x++)
        {
            // var rgba = wb.GetPixel(x, y);    // This is not working, only returnning empty pixels (A:0, R:0, G:0, B:0)

            // Get RGBA value of pixel
            var rgba = new Color {
                R = data[x * 4 + y * decoder.PixelWidth * 4 + 0],
                G = data[x * 4 + y * decoder.PixelWidth * 4 + 1],
                B = data[x * 4 + y * decoder.PixelWidth * 4 + 2],
                A = data[x * 4 + y * decoder.PixelWidth * 4 + 3]
            };

            // Array can't have index -1 and -1 is for gray what is default
            if (molecule.Owner != -1)
            {
                // Colorize pixel
                var z = ((rgba.R + rgba.G + rgba.B) / 3.0) / 256;
                rgba.R = Convert.ToByte(z * Settings.Colors[molecule.Owner].Item1.Color.R);
                rgba.G = Convert.ToByte(z * Settings.Colors[molecule.Owner].Item1.Color.G);
                rgba.B = Convert.ToByte(z * Settings.Colors[molecule.Owner].Item1.Color.B);
                data[x * 4 + y * decoder.PixelWidth * 4 + 0] = rgba.R;
                data[x * 4 + y * decoder.PixelWidth * 4 + 1] = rgba.G;
                data[x * 4 + y * decoder.PixelWidth * 4 + 2] = rgba.B;
            }

            wb.SetPixel(x, y, rgba); // I tried to connect byte[] and WriteAbleBitmap via stream but Failed so I'm using this
        }
    }

    if (atoms == molecule.Atoms)    // Because it's async method so If value is already different don't change it to old picture
    {
        molecule.parent.Content = new Image();
        (molecule.parent.Content as Image).Source = wb;
        (molecule.parent.Content as Image).Width = 24;
        (molecule.parent.Content as Image).Height = 24;
    }

    Molecule.Reaction--;    // done changing picture
}

internal static async Task<IRandomAccessStream> GetStream(string relativePath)
{
    var storageFile = await Package.Current.InstalledLocation.GetFileAsync(relativePath.Replace('/', '\\'));
    var stream = await storageFile.OpenReadAsync();
    return stream;
}