Merge pull request #32 from dotnet-campus/t/lindexi/EmuPercentage

提供 EmuPercentage 支持传入百分号字符串

Author: ZhengDaoWang

src/dotnetCampus.OpenXmlUnitConverter/EmuPercentage.cs

@@ -1,4 +1,7 @@
-namespace dotnetCampus.OpenXmlUnitConverter
+using System;
+using DocumentFormat.OpenXml;
+
+namespace dotnetCampus.OpenXmlUnitConverter
 {
     /// <summary>
     /// 用 Emu 表示的百分数
@@ -14,6 +17,54 @@ public EmuPercentage(double value)
             Value = value;
         }
 
+        /// <summary>
+        /// 用 Emu 表示的百分数
+        /// </summary>
+        /// <param name="int32Value">支持传入带百分号的内容</param>
+        public EmuPercentage(Int32Value int32Value) : this(int32Value.InnerText)
+        {
+        }
+
+        internal EmuPercentage(string? percentageText)
+        {
+            if (!string.IsNullOrEmpty(percentageText))
+            {
+                if (int.TryParse(percentageText, out var intValue))
+                {
+                    Value = intValue;
+                    return;
+                }
+                else
+                {
+                    // 如果是带了百分比的
+                    if (percentageText!.Length > 1 && percentageText.EndsWith("%"))
+                    {
+#if NETCOREAPP3_1_OR_GREATER
+                        var percentageSpan = percentageText.AsSpan().Slice(0, percentageText.Length - 1);
+                        if (double.TryParse(percentageSpan, out var doubleValue))
+#else
+                        var newPercentageText = percentageText.Substring(0, percentageText.Length - 1);
+                        if (double.TryParse(newPercentageText, out var doubleValue))
+#endif
+                        {
+                            // 根据 OpenXml 规则，这里和像素百分比转换是 1000 倍
+                            var pixelPercentageValue = doubleValue * 1000;
+
+                            // 这里的百分比一定是 Pixel 的百分比级的，需要经过转换才能计算为 Emu 的百分比
+                            // 为了将 PixelPercentageValue 转换为 EmuPercentage 类型，需要经过换算逻辑
+                            var pixel = new Pixel(pixelPercentageValue);
+                            var emuPercentageValue = pixel.ToEmu();
+
+                            Value = emuPercentageValue.Value;
+                            return;
+                        }
+                    }
+                }
+            }
+
+            throw new ArgumentException($"Can not convert PercentageText={percentageText} to {nameof(EmuPercentage)} value.");
+        }
+
         /// <summary>
         /// 用 Emu 表示的百分数
         /// </summary>

src/dotnetCampus.OpenXmlUnitConverter/Percentage.cs

@@ -24,8 +24,7 @@ public Percentage(int value)
         /// 从一个 OpenXML 的数值转换为百分比
         /// </summary>
         /// [dotnet OpenXML 修复 Office 文档里面的百分比内容包含百分号](https://blog.lindexi.com/post/dotnet-OpenXML-%E4%BF%AE%E5%A4%8D-Office-%E6%96%87%E6%A1%A3%E9%87%8C%E9%9D%A2%E7%9A%84%E7%99%BE%E5%88%86%E6%AF%94%E5%86%85%E5%AE%B9%E5%8C%85%E5%90%AB%E7%99%BE%E5%88%86%E5%8F%B7.html )
-
-        public Percentage(Int32Value int32Value) : this(int32Value.InnerText)
+        public Percentage(Int32Value int32Value) : this(int32Value.InnerText ?? string.Empty)
         {
         }
 
@@ -62,7 +61,8 @@ internal Percentage(string percentageText)
         /// <summary>
         /// 百分比与 OpenXML 比例
         /// </summary>
-        public const double Precision = 100000.0;
+        /// 百分比与 OpenXML 比例的数值差值是 1000 倍，再乘以百分比的 100 倍
+        public const double Precision = 1000 * 100.0;
 
         /// <summary>
         ///     表示 0 的值

tests/dotnetCampus.OpenXmlUnitConverter.Tests/EmuPercentageTest.cs

@@ -0,0 +1,25 @@
+using DocumentFormat.OpenXml;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MSTest.Extensions.Contracts;
+
+namespace dotnetCampus.OpenXmlUnitConverter.Tests;
+
+[TestClass]
+public class EmuPercentageTest
+{
+    [ContractTestCase]
+    public void CreateEmuPercentage()
+    {
+        "传入带百分号的 Int32Value 值，可以成功转换为 EmuPercentage 对象".Test(() =>
+        {
+            var int32Value = new Int32Value
+            {
+                InnerText = "10%"
+            };
+
+            var emuPercentage = new EmuPercentage(int32Value);
+            var pixelPercentage = emuPercentage.ToPixelPercentage();
+            Assert.AreEqual(10 * 1000, pixelPercentage.IntValue);
+        });
+    }
+}