Summary of problems encountered in "training" project practice and solutions

The problems encountered in the training in this summary to avoid encountering the same problem in the future to find a half day to solve

"Rookie Problem Solving"

1. Data type error when converting JSON string when querying data " additional information: The DataSet does not support system.nullable<>. "

"Error" table. Columns.Add (Prop. Name, Prop. PropertyType) ; "Red is the error data type"

"Solution" to change the above sentence: table. Columns.Add (Prop.  Name); To resolve this issue

        /// <summary>        ///Create a table/// </summary>        /// <typeparam name= "T" ></typeparam>        /// <returns></returns>         Public StaticDataTable createtable<t>() {Type EntityType=typeof(T); DataTable Table=NewDataTable (entitytype.name); PropertyDescriptorCollection Properties=typedescriptor.getproperties (EntityType); foreach(PropertyDescriptor propinchproperties) {                //table. Columns.Add (Prop. Name);//change this to solve the wrong problemtable. Columns.Add (Prop. Name, Prop. PropertyType);//data type error when converting JSON string when querying data " additional information: The DataSet does not support system.nullable<>. "            }            returntable; }

Summary of problems encountered in "training" project practice and solutions