ImgHelper.AddText优化

Coldairarrow · Jun 22, 2021 · 98c1f50 · 98c1f50
1 parent f74a0b0
commit 98c1f50
Showing 1 changed file with 37 additions and 62 deletions.
diff --git a/src/Colder.CommonUtil/Helpers/ImgHelper.cs b/src/Colder.CommonUtil/Helpers/ImgHelper.cs
@@ -11,16 +11,6 @@ namespace Colder.CommonUtil
     /// </summary>
     public class ImgHelper
     {
-        /// <summary>
-        /// 从文件获取图片
-        /// </summary>
-        /// <param name="fileName">文件名</param>
-        /// <returns></returns>
-        public static Image GetImgFromFile(string fileName)
-        {
-            return Image.FromFile(fileName);
-        }
-
         /// <summary>
         /// 从base64字符串读入图片
         /// </summary>
@@ -145,74 +135,59 @@ public static string GetBase64String(string base64UrlStr)
         }
 
         /// <summary>
-        /// 图片添加文字，文字大小自适应
+        /// 图片添加文字水印，文字大小自适应
         /// </summary>
         /// <param name="image">图片</param>
-        /// <param name="locationLeftTop">左上角定位像素(x1,y1)</param>
-        /// <param name="locationRightBottom">右下角定位像素(x2,y2)</param>
+        /// <param name="area">文字区域</param>
         /// <param name="text">文字内容</param>
         /// <param name="color">字体颜色</param>
         /// <param name="fontName">字体名称</param>
         /// <returns>添加文字后的Bitmap对象</returns>
-        public static Image AddText(Image image, (int x, int y) locationLeftTop, (int x, int y) locationRightBottom, string text, Color color, string fontName = "ttf")
+        public static Image AddText(Image image, Rectangle area, string text, Color color, string fontName = "微软雅黑")
         {
             int width = image.Width;
             int height = image.Height;
             Bitmap bmp = new Bitmap(width, height);
-            using Graphics graph = Graphics.FromImage(bmp);
-
-            // 计算文字区域
-            // 左上角
-            float x1 = locationLeftTop.x;
-            float y1 = locationLeftTop.y;
-            // 右下角
-            float x2 = locationRightBottom.x;
-            float y2 = locationRightBottom.y;
-            // 区域宽高
-            float fontWidth = x2 - x1;
-            float fontHeight = y2 - y1;
-
-            // 初次估计先用文字区域高度作为文字字体大小，后面再做调整，单位为px
-            float fontSize = fontHeight;
-
-            Font font = new Font(fontName, fontSize, GraphicsUnit.Pixel);
-            SizeF sf = graph.MeasureString(text, font);
-
-            int times = 0;
-
-            // 调整字体大小以适应文字区域
-            if (sf.Width > fontWidth)
+            using (Graphics graph = Graphics.FromImage(bmp))
             {
-                while (sf.Width > fontWidth)
+                // 计算文字区域
+                // 区域宽高
+                float fontWidth = area.Width;
+                float fontHeight = area.Height;
+                // 初次估计先用文字区域高度作为文字字体大小，后面再做调整，单位为px
+                float fontSize = fontHeight;
+                Font font = new Font(fontName, fontSize, GraphicsUnit.Pixel);
+                SizeF sf = graph.MeasureString(text, font);
+                int times = 0;
+                // 调整字体大小以适应文字区域
+                if (sf.Width > fontWidth)
                 {
-                    fontSize -= 0.1f;
-                    font = new Font(fontName, fontSize, GraphicsUnit.Pixel);
-                    sf = graph.MeasureString(text, font);
-
-                    times++;
+                    while (sf.Width > fontWidth)
+                    {
+                        fontSize -= 0.1f;
+                        font = new Font(fontName, fontSize, GraphicsUnit.Pixel);
+                        sf = graph.MeasureString(text, font);
+                        times++;
+                    }
                 }
-            }
-            else if (sf.Width < fontWidth)
-            {
-                while (sf.Width < fontWidth)
+                else if (sf.Width < fontWidth)
                 {
-                    fontSize += 0.1f;
-                    font = new Font(fontName, fontSize, GraphicsUnit.Pixel);
-                    sf = graph.MeasureString(text, font);
-
-                    times++;
+                    while (sf.Width < fontWidth)
+                    {
+                        fontSize += 0.1f;
+                        font = new Font(fontName, fontSize, GraphicsUnit.Pixel);
+                        sf = graph.MeasureString(text, font);
+                        times++;
+                    }
                 }
+                // 最终的得出的字体所占区域一般不会刚好等于实际区域
+                // 所以根据两个区域的相差之处再把文字开始位置(左上角定位)稍微调整一下
+                var x1 = area.X + ((fontWidth - sf.Width) / 2);
+                var y1 = area.Y + ((fontHeight - sf.Height) / 2);
+                graph.DrawImage(image, 0, 0, width, height);
+                graph.DrawString(text, font, new SolidBrush(color), x1, y1);
+                return bmp;
             }
-
-            // 最终的得出的字体所占区域一般不会刚好等于实际区域
-            // 所以根据两个区域的相差之处再把文字开始位置(左上角定位)稍微调整一下
-            x1 += (fontWidth - sf.Width) / 2;
-            y1 += (fontHeight - sf.Height) / 2;
-
-            graph.DrawImage(image, 0, 0, width, height);
-            graph.DrawString(text, font, new SolidBrush(color), x1, y1);
-
-            return bmp;
         }
     }
 }