WPF 文本描边+外发光效果实现

解决思路：

（1）描边效果可以将文本字符串用GDI+生成Bitmap，然后转成BitmapImage，再用WPF的Image控件显示。

（2）外发光效果用WPF自带的Effect实现

代码：

 1 using System;
 2 using System.Drawing;
 3 using System.Drawing.Drawing2D;
 4 using System.Drawing.Text;
 5 using System.IO;
 6
 7 namespace TextHighLighthDemo
 8 {
 9     public class FancyText
10     {
11         private static System.Windows.Media.Imaging.BitmapImage BitmapToBitmapImage(System.Drawing.Bitmap bitmap)
12         {
13             using (MemoryStream stream = new MemoryStream())
14             {
15                 bitmap.Save(stream, System.Drawing.Imaging.ImageFormat.Png); // 坑点：格式选Bmp时，不带透明度
16
17                 stream.Position = 0;
18                 System.Windows.Media.Imaging.BitmapImage result = new System.Windows.Media.Imaging.BitmapImage();
19                 result.BeginInit();
20                 result.CacheOption = System.Windows.Media.Imaging.BitmapCacheOption.OnLoad;
21                 result.StreamSource = stream;
22                 result.EndInit();
23                 result.Freeze();
24                 return result;
25             }
26         }
27
28         private static Bitmap ImageFromText(string strText, Font fnt, Color clrFore, Color clrBack, int blurAmount = 5)
29         {
30             Bitmap bmpOut = null;
31             int sunNum = 255;  //光晕的值
32             using (Graphics g = Graphics.FromHwnd(IntPtr.Zero))
33             {
34                 SizeF sz = g.MeasureString(strText, fnt);
35                 using (Bitmap bmp = new Bitmap((int)sz.Width, (int)sz.Height))
36                 using (Graphics gBmp = Graphics.FromImage(bmp))
37                 using (SolidBrush brBack = new SolidBrush(Color.FromArgb(sunNum, clrBack.R, clrBack.G, clrBack.B)))
38                 using (SolidBrush brFore = new SolidBrush(clrFore))
39                 {
40                     gBmp.SmoothingMode = SmoothingMode.HighQuality;
41                     gBmp.InterpolationMode = InterpolationMode.HighQualityBilinear;
42                     gBmp.TextRenderingHint = TextRenderingHint.AntiAliasGridFit;
43                     gBmp.DrawString(strText, fnt, brBack, 0, 0);
44                     bmpOut = new Bitmap(bmp.Width + blurAmount, bmp.Height + blurAmount);
45                     using (Graphics gBmpOut = Graphics.FromImage(bmpOut))
46                     {
47                         gBmpOut.SmoothingMode = SmoothingMode.HighQuality;
48                         gBmpOut.InterpolationMode = InterpolationMode.HighQualityBilinear;
49                         gBmpOut.TextRenderingHint = TextRenderingHint.AntiAliasGridFit;
50                         //阴影光晕
51                         for (int x = 0; x <= blurAmount; x++)
52                         {
53                             for (int y = 0; y <= blurAmount; y++)
54                             {
55                                 gBmpOut.DrawImageUnscaled(bmp, x, y);
56                             }
57                         }
58                         gBmpOut.DrawString(strText, fnt, brFore, blurAmount / 2, blurAmount / 2);
59                     }
60                 }
61             }
62             return bmpOut;
63         }
64
65         /// <summary>
66         /// 文本转图片
67         /// </summary>
68         /// <param name="strText"></param>
69         /// <param name="fnt"></param>
70         /// <param name="clrFore"></param>
71         /// <param name="clrBack"></param>
72         /// <param name="blurAmount"></param>
73         /// <returns></returns>
74         public static System.Windows.Media.Imaging.BitmapImage BitmapImageFromText(string strText, Font fnt, Color clrFore, Color clrBack, int blurAmount = 5)
75         {
76
77             return BitmapToBitmapImage(ImageFromText(strText, fnt, clrFore, clrBack, blurAmount));
78         }
79
80     }
81 }

应用：

（1）XMAL代码

<Grid Background="Gray">
        <StackPanel Height="300">
            <Image x:Name="img" Height="70" VerticalAlignment="Top" >
                <Image.Effect>
                    <DropShadowEffect Color="#00ffff" ShadowDepth="0" BlurRadius="15"/>
                </Image.Effect>
            </Image>
            <Image x:Name="img1" Height="35" VerticalAlignment="Top" Margin="0 10 0 0">
                <Image.Effect>
                    <DropShadowEffect Color="#00ffff" ShadowDepth="0" BlurRadius="5"/>
                </Image.Effect>
            </Image>
        </StackPanel>
    </Grid>

（2）code behind

var backColor = System.Drawing.ColorTranslator.FromHtml("#037be2");
var forColor= System.Drawing.ColorTranslator.FromHtml("#ffffff");
img.Source = FancyText.BitmapImageFromText("测试字体，微软雅黑", new System.Drawing.Font("Microsoft YaHei", 60, System.Drawing.FontStyle.Bold), forColor, backColor, 6);
img1.Source = FancyText.BitmapImageFromText("外发光+描边", new System.Drawing.Font("Microsoft YaHei", 30, System.Drawing.FontStyle.Bold), forColor, backColor, 3);

效果：

优化点：可以将FancyText封装成自定义控件，定义描边大小，颜色值等依赖属性，直接为WPF使用。