DLL是否返回DataTable？

Question

  

可能重复：
  Controls are not inherited in winforms

我在winform的应用程序中有这样的函数

public DataTable GetAllPrimaryKeyTables(string ConnectionString)
{ 
    // Create the datatable 
    DataTable dtListOfPrimaryKeyTables = new DataTable("tableNames");

    // Query to select primary key tables.
    string selectPrimaryKeyTables = @"SELECT 
                                           TABLE_NAME
                                          AS
                                           TABLES
                                        FROM 
                                           INFORMATION_SCHEMA.TABLE_CONSTRAINTS
                                       WHERE 
                                           CONSTRAINT_TYPE = 'PRIMARY KEY'
                                         AND
                                           TABLE_NAME <> 'dtProperties'
                                    ORDER BY
                                           TABLE_NAME";

    // put your SqlConnection and SqlCommand into using blocks! 
    using(SqlConnection sConnection = new SqlConnection(ConnectionString))
    using(SqlCommand sCommand = new SqlCommand(selectPrimaryKeyTables, sConnection))
    {
        try
        {
            // Create the dataadapter object 
            SqlDataAdapter sDataAdapter = new SqlDataAdapter(sCommand);

            EventLog objLog = new EventLog("Check1");
            objLog.Source = "MFDBAnalyser";
            objLog.WriteEntry("check1 successful: " + selectPrimaryKeyTables);


            // Fill the datatable - no need to open the connection, the SqlDataAdapter will do that all by itself  
            // (and also close it again after it is done) 
            sDataAdapter.Fill(dtListOfPrimaryKeyTables);
            //using(StringWriter sw = new StringWriter())
            //{
            //    dtListOfPrimaryKeyTables.WriteXml(sw);
            //    sw.WriteLine();
            //    result = sw.ToString();
            //}
        }
        catch(Exception ex)
        {
            //All the exceptions are handled and written in the EventLog. 
            EventLog log = new EventLog("Application");
            log.Source = "MFDBAnalyser";
            log.WriteEntry(ex.Message);
        }
    }

    // return the data table to the caller 
    return dtListOfPrimaryKeyTables;

}

并称之为

public DataTable RunAnalysis(string ConnectionString)
{
    return GetAllPrimaryKeyTables(ConnectionString);
}

关于按钮的调试，请单击此处，我​​无法获取DataTable ...它只返回一个空的DataTable ...

private void btnStartAnalysis_Click(object sender, EventArgs e)
{
    SqlConnectionStringBuilder objConnectionString = new SqlConnectionStringBuilder();
    objConnectionString.DataSource = txtHost.Text;
    objConnectionString.UserID = txtUsername.Text;
    objConnectionString.Password = txtPassword.Text;
    string[] arrArgs = { objConnectionString.ConnectionString };

    string assemblyName = "PrimaryKeyChecker.dll";
    Assembly assembly = Assembly.LoadFrom(assemblyName);
    Type local_type = assembly.GetType("PrimaryKeyChecker.PrimaryKeyChecker");
    IMFDBAnalyserPlugin analyser = (IMFDBAnalyserPlugin) Activator.CreateInstance(local_type);
    DataTable response = analyser.RunAnalysis(objConnectionString.ConnectionString);

在DataTable响应中，我应该得到第一个函数调用的表列表，但为什么我得到一个空的DataTable。

希望有人能帮助我并解决问题所在!!