[R] 给Maidata类的常用信息属性加上setter

Author: Starrah

README.md

@@ -109,7 +109,7 @@ return maidataText; // maidataText即为转谱结果
     - bool `isUtage` (默认为false): 仅影响生成的MA2的文件头区域的`FES_MODE`的值是1还是0，一般来说是不重要的。
 
 #### 更多示例（异常处理）
-注意：当解析/生成步骤失败时，会抛出ConversionException异常，其中含有Alerts属性，是转谱过程中遇到的错误和警告等信息。（类比于C语言编译器会打印出Error和Warning信息）  
+注意：当解析/生成步骤失败时，会抛出`ConversionException`异常，其中含有`Alerts`属性，是转谱过程中遇到的错误和警告等信息。（类比于C语言编译器会打印出Error和Warning信息）  
 因此，建议您采用try-catch的写法，捕获可能出现的异常，并无论转谱成功失败、总是打印出Alert信息：（下面例子以Simai → MA2为例，如果反过来转则直接更换Parser和Generator即可）
 ```csharp
 using System.Text;
@@ -135,7 +135,7 @@ catch (ConversionException e)
     throw;
 }
 finally
-{
+{ // 无论转换成功还是失败，都打印出Alert信息
     foreach (Alert a in alerts) Console.Error.WriteLine(a);
 }
 ```

maidata/Maidata.cs

@@ -1,3 +1,4 @@
+using System.Globalization;
 using System.Text;
 using MuConvert.utils;
 
@@ -85,11 +86,40 @@ private void _putKey(string? key, StringBuilder content)
         return (levels, infos);
     }
 
-    public string Title => this.GetValueOrDefault("title", "");
-    public string Artist => this.GetValueOrDefault("artist", "");
-    public float? WholeBpm => float.TryParse(this.GetValueOrDefault("wholebpm", ""), out var wholebpm) ? wholebpm : null;
-    public float First => float.TryParse(this.GetValueOrDefault("first", ""), out var first) ? first : 0f;
-    public int ClockCount => int.TryParse(this.GetValueOrDefault("clock_count", ""), out var clockCount) ? clockCount : 4;
+    public string Title
+    {
+        get => this.GetValueOrDefault("title", "");
+        set => this["title"] = value ?? "";
+    }
+    
+    public string Artist
+    {
+        get => this.GetValueOrDefault("artist", "");
+        set => this["artist"] = value ?? "";
+    }
+    
+    public float? WholeBpm
+    {
+        get => float.TryParse(this.GetValueOrDefault("wholebpm", ""), out var wholebpm) ? wholebpm : null;
+        set
+        {
+            if (value is null) Remove("wholebpm");
+            else this["wholebpm"] = value.Value.ToString(CultureInfo.InvariantCulture);
+        }
+    }
+    
+    public float First
+    {
+        get => float.TryParse(this.GetValueOrDefault("first", ""), out var first) ? first : 0f;
+        set => this["first"] = $"{value:0.####}";
+    }
+    
+    public int ClockCount
+    {
+        get => int.TryParse(this.GetValueOrDefault("clock_count", ""), out var clockCount) ? clockCount : 4;
+        set => this["clock_count"] = value.ToString();
+    }
+    
     public (float, float?)? Demo
     {
         get
@@ -98,6 +128,20 @@ private void _putKey(string? key, StringBuilder content)
             float? demoLen = float.TryParse(this.GetValueOrDefault("demo_len", ""), out var v) ? v : null;
             return (demoStart, demoLen);
         }
+        set
+        {
+            if (value is null)
+            {
+                Remove("demo_seek");
+                Remove("demo_len");
+                return;
+            }
+
+            var (start, len) = value.Value;
+            this["demo_seek"] = $"{start:0.####}";
+            if (len is null) Remove("demo_len");
+            else this["demo_len"] = $"{len:0.####}";
+        }
     }
 
     public override string ToString()