WPF实现文本描边+外发光效果的示例代码
时间:2022-07-10 09:40:54|栏目:.NET代码|点击: 次
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:
using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Drawing.Text; using System.IO; namespace TextHighLighthDemo { public class FancyText { private static System.Windows.Media.Imaging.BitmapImage BitmapToBitmapImage(System.Drawing.Bitmap bitmap) { using (MemoryStream stream = new MemoryStream()) { bitmap.Save(stream, System.Drawing.Imaging.ImageFormat.Png); // 坑点:格式选Bmp时,不带透明度 stream.Position = 0; System.Windows.Media.Imaging.BitmapImage result = new System.Windows.Media.Imaging.BitmapImage(); result.BeginInit(); result.CacheOption = System.Windows.Media.Imaging.BitmapCacheOption.OnLoad; result.StreamSource = stream; result.EndInit(); result.Freeze(); return result; } } private static Bitmap ImageFromText(string strText, Font fnt, Color clrFore, Color clrBack, int blurAmount = 5) { Bitmap bmpOut = null; int sunNum = 255; //光晕的值 using (Graphics g = Graphics.FromHwnd(IntPtr.Zero)) { SizeF sz = g.MeasureString(strText, fnt); using (Bitmap bmp = new Bitmap((int)sz.Width, (int)sz.Height)) using (Graphics gBmp = Graphics.FromImage(bmp)) using (SolidBrush brBack = new SolidBrush(Color.FromArgb(sunNum, clrBack.R, clrBack.G, clrBack.B))) using (SolidBrush brFore = new SolidBrush(clrFore)) { gBmp.SmoothingMode = SmoothingMode.HighQuality; gBmp.InterpolationMode = InterpolationMode.HighQualityBilinear; gBmp.TextRenderingHint = TextRenderingHint.AntiAliasGridFit; gBmp.DrawString(strText, fnt, brBack, 0, 0); bmpOut = new Bitmap(bmp.Width + blurAmount, bmp.Height + blurAmount); using (Graphics gBmpOut = Graphics.FromImage(bmpOut)) { gBmpOut.SmoothingMode = SmoothingMode.HighQuality; gBmpOut.InterpolationMode = InterpolationMode.HighQualityBilinear; gBmpOut.TextRenderingHint = TextRenderingHint.AntiAliasGridFit; //阴影光晕 for (int x = 0; x <= blurAmount; x++) { for (int y = 0; y <= blurAmount; y++) { gBmpOut.DrawImageUnscaled(bmp, x, y); } } gBmpOut.DrawString(strText, fnt, brFore, blurAmount / 2, blurAmount / 2); } } } return bmpOut; } /// <summary> /// 文本转图片 /// </summary> /// <param name="strText"></param> /// <param name="fnt"></param> /// <param name="clrFore"></param> /// <param name="clrBack"></param> /// <param name="blurAmount"></param> /// <returns></returns> public static System.Windows.Media.Imaging.BitmapImage BitmapImageFromText(string strText, Font fnt, Color clrFore, Color clrBack, int blurAmount = 5) { return BitmapToBitmapImage(ImageFromText(strText, fnt, clrFore, clrBack, blurAmount)); } } }
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。