在运行我的应用程序时，当我运行存储过程时，SqlAdapter不返回任何数据

看起来它连接良好，除了返回数据或在datagridview上显示数据外，它做了所有事情。我不确定这到底有什么问题。如果我在SQL Server Management Studio中运行它，它在本地机器上运行良好。

它似乎没有正确运行这里虽然，它只是一个按钮，我点击，但没有返回给我。

SqlConnection conn = new SqlConnection(connectionstring);
SqlCommand StoredProcedureCommand = new SqlCommand("storedprocedure", conn);
StoredProcedureCommand.CommandType = CommandType.StoredProcedure;
SqlParameter myParam1 = StoredProcedureCommand.Parameters.Add("@p1", SqlDbType.VarChar, 20);
myParam1.Value = "Arg";
SqlParameter myParam2 = StoredProcedureCommand.Parameters.Add("@p2", SqlDbType.VarChar, 300);
myParam2.Value = "Gra";
try
{
    conn.Open();
    MessageBox.Show("Database Connection Success");
}
catch (Exception conerr)
{
    MessageBox.Show("Database Connection Failed");
}
try
{
    StoredProcedureCommand.ExecuteNonQuery();
    MessageBox.Show("Running stored procedure succeeded");
}
catch (Exception proerr)
{
    MessageBox.Show("Running stored procedure failed");
}
try
{
    using (SqlDataAdapter adap = new SqlDataAdapter(StoredProcedureCommand))
    {
        DataTable dt = new DataTable();
        int rowCount = dt.Rows.Count;
        adap.Fill(dt);
        dataGridView1.DataSource = dt;
        MessageBox.Show("Data returned fine" + " This many rows were returned" + rowCount.ToString());
    }
}
catch (Exception erradapt)
{
    MessageBox.Show("Error retrieving data to grid" +  erradapt.ToString());
}
try
{  
    conn.Close();
    MessageBox.Show("Closing database connection");
}
catch (Exception errclose)
{
    MessageBox.Show("Error closing database connection");
}