继承时缺少方法异常

Question

我有以下继承自DataTable的类:

public class ExcelStaticDataTable : DataTable
{
    public List<ExcelStaticDataTable> SubTables { get; set; }
    public ExcelStaticDataTable(string tableName): base(tableName)
    {
        SubTables = new List<ExcelStaticDataTable>();
    }
}

你知道为什么我在MissingMethodException执行以下操作时获得"为此对象定义的无参数构造函数":

ExcelStaticDataTable table=new ExcelStaticDataTable("table1");
table.Clone();

这两段代码都在不同的dll中,只是为了澄清.这里的堆栈跟踪:

at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)
   at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
   at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
   at System.Activator.CreateInstance(Type type, Boolean nonPublic)
   at System.Data.DataTable.CreateInstance()
   at System.Data.DataTable.Clone(DataSet cloneDS)
   at System.Data.DataTable.Clone()
   at System.Data.DataTable.Copy()
   at ..........cs:line 35

谢谢.

Answer 1

我怀疑其他代码使用object newObj = Activator.CreateInstance(GetType());作为的一部分Clone().这需要默认用法中的公共无参数构造函数.否则它抛出一个MissingMethodException.

更新:显示堆栈跟踪的更新确认了这一点.

我怀疑你可以通过覆盖CreateInstance方法来解决这个问题:

protected override DataTable CreateInstance()
{
    return new ExcelStaticDataTable(TableName);
}