!545 完善代码生成：实体类生成时，可空属性的标记

😁Merge pull request !545 from 陈龙/pr-next

Admin.NET/Admin.NET.Web.Entry/wwwroot/Template/Entity.cs.vm

@@ -23,7 +23,7 @@ else if(@Model.BaseClassName=="" && !@column.IsPrimarykey){
           @:/// <summary>
           @:/// @column.ColumnDescription
           @:/// </summary>
-          @:public @column.DataType @column.DbColumnName { get; set; }
+          @:public @column.DataType(@column.IsNullable ? "?" : "") @column.DbColumnName { get; set; }
 }
 else if(@Model.BaseClassName!="" && @column.IsPrimarykey && @column.DbColumnName.ToLower()!="id"){
           @:/// <summary>
@@ -36,7 +36,7 @@ else if(@Model.BaseClassName!="" && !@column.IsPrimarykey && @column.DbColumnNam
           @:/// <summary>
           @:/// @column.ColumnDescription
           @:/// </summary>
-          @:public @column.DataType @column.DbColumnName { get; set; }
+          @:public @column.DataType(@column.IsNullable ? "?" : "") @column.DbColumnName { get; set; }
 }
 }
 }