【WIN10】WIN2D——繪製文字

先看下截圖：

做了幾個效果：普通、倒影、陰影、歌詞。

普通效果代碼：

private void normal_Draw(Microsoft.Graphics.Canvas.UI.Xaml.CanvasControl sender, Microsoft.Graphics.Canvas.UI.Xaml.CanvasDrawEventArgs args)
{
    CanvasTextFormat fmt = new CanvasTextFormat();
    fmt.FontFamily = "Vladimir Script";
    fmt.FontSize = 30;
    args.DrawingSession.DrawText("Hello Win2D", 0, 0, Color.FromArgb(255, 255, 255, 255), fmt);
}

倒影效果代碼，這個是使用scale變換做到的，使用scaleY=-1，就把它的Y值調換，達到我們的效果了，同時還必須設定圓心，然它會跑到其它地方了。

同時，要弄一個逐漸消失的效果，即要設透明度。

private void rotate_Draw(Microsoft.Graphics.Canvas.UI.Xaml.CanvasControl sender, Microsoft.Graphics.Canvas.UI.Xaml.CanvasDrawEventArgs args)
{

    CanvasTextFormat fmt = new CanvasTextFormat();
    fmt.FontFamily = "Vladimir Script";
    fmt.FontSize = 30;

    args.DrawingSession.DrawText("Hello Win2D", 0, 0, Color.FromArgb(255, 255, 255, 255), fmt);

    CanvasGradientStop[] gradientStops = new CanvasGradientStop[2];
    gradientStops[0] = new CanvasGradientStop();
    gradientStops[0].Color = Color.FromArgb(0, 0, 0, 0);
    gradientStops[0].Position =0f;

    gradientStops[1] = new CanvasGradientStop();
    gradientStops[1].Color = Color.FromArgb(255, 255, 255, 255);
    gradientStops[1].Position = 1f;

    CanvasLinearGradientBrush br = new CanvasLinearGradientBrush(sender, gradientStops);
    br.StartPoint = new Vector2(0, 50);
    br.EndPoint = new Vector2(0, 80);

    args.DrawingSession.Transform = Matrix3x2.CreateScale(new Vector2(1, -1), new Vector2(0, 55));
    args.DrawingSession.DrawText("Hello Win2D", 0, 40, br, fmt);
}

陰影效果。

這個是先畫一個模糊的背景，再在上面畫上清晰的文字。

private void shadow_Draw(Microsoft.Graphics.Canvas.UI.Xaml.CanvasControl sender, Microsoft.Graphics.Canvas.UI.Xaml.CanvasDrawEventArgs args)
{
    CanvasTextFormat fmt = new CanvasTextFormat() { FontSize = 72, FontFamily = "Vladimir Script" };

    var myBitmap = new CanvasRenderTarget(sender, 512, 96);
    using (var ds = myBitmap.CreateDrawingSession())
    {
        ds.DrawText("Hello Win2D", 0, 0, Colors.Green, fmt);
    }

    var blur = new GaussianBlurEffect
    {
        BlurAmount = 3,
        Source = myBitmap
    };

    args.DrawingSession.DrawImage(blur, 4, 4);
    args.DrawingSession.DrawText("Hello Win2D", 0, 0, Colors.Green, fmt);
}

歌詞效果就相對比較簡單了。主要要注意的是，要把字符的換行設為NoWrapping。

private void song_Draw(Microsoft.Graphics.Canvas.UI.Xaml.CanvasControl sender, Microsoft.Graphics.Canvas.UI.Xaml.CanvasDrawEventArgs args)
{
    var fmt = new CanvasTextFormat();
    fmt.FontFamily = "微软雅黑";
    fmt.FontSize = 72;
    fmt.WordWrapping = CanvasWordWrapping.NoWrap;
    fmt.Options = CanvasDrawTextOptions.Clip;

    Rect rcNormal = new Rect(0, 0, sender.ActualWidth, sender.ActualHeight);
    args.DrawingSession.DrawText(songInfo_, rcNormal, Colors.Aqua, fmt);

    Rect rcSang = new Rect(0, 0, songPos_, sender.ActualHeight);
    args.DrawingSession.DrawText(songInfo_, rcSang, Colors.Yellow, fmt);
}

設一個定時器，動態改變 songPos_ 即可。