无法在数据绑定的datagridview控件vb.net上设置columncount属性

Question

我有一个代码在datagridview显示记录和过滤数据时有效。

ShowRecord代码：

Using cmd As New SqlClient.SqlCommand("dbo.uspSELECTALL", cn)

    da.SelectCommand = cmd
    dt.Clear()
    da.Fill(dt)
    dgv1.RowTemplate.Height = 30
    dgv1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.DisplayedCellsExceptHeaders
    dgv1.ColumnCount = 8
    SelectedRows()
    dgv1.AutoGenerateColumns = False
    dgv1.Columns(0).Name = "Student ID"
    dgv1.Columns(0).DataPropertyName = "StudentID"
    dgv1.Columns(1).Name = "Last Name"
    dgv1.Columns(1).DataPropertyName = "SurName"
    dgv1.Columns(2).Name = "First Name"
    dgv1.Columns(2).DataPropertyName = "FirstName"
    dgv1.Columns(3).Name = "Middle Name"
    dgv1.Columns(3).DataPropertyName = "MiddleName"
    dgv1.Columns(4).Name = "Gender"
    dgv1.Columns(4).DataPropertyName = "Gender"
    dgv1.Columns(5).Name = "Birthday"
    dgv1.Columns(5).DataPropertyName = "Birthday"
    dgv1.Columns(6).Name = "Age"
    dgv1.Columns(6).DataPropertyName = "Age"
    dgv1.Columns(7).Name = "ContactNumber"
    dgv1.Columns(7).DataPropertyName = "TelNum"
    dgv1.DataSource = dt

End Using

FilterData代码：

Using cmd As New SqlClient.SqlCommand("dbo.uspYearFilter", cn)
    cmd.Parameters.AddWithValue("@Year", cboYear.Text)
    cmd.CommandType = CommandType.StoredProcedure
    da.SelectCommand = cmd
    dt.Clear()
    da.Fill(dt)
    dgv1.RowTemplate.Height = 30
    dgv1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.DisplayedCellsExceptHeaders
    dgv1.AutoGenerateColumns = False
    dgv1.Columns(0).Name = "Student ID"
    dgv1.Columns(0).DataPropertyName = "StudentID"
    dgv1.Columns(1).Name = "Last Name"
    dgv1.Columns(1).DataPropertyName = "SurName"
    dgv1.Columns(2).Name = "First Name"
    dgv1.Columns(2).DataPropertyName = "FirstName"
    dgv1.Columns(3).Name = "Middle Name"
    dgv1.Columns(3).DataPropertyName = "MiddleName"
    dgv1.Columns(4).Name = "Gender"
    dgv1.Columns(4).DataPropertyName = "Gender"
    dgv1.Columns(5).Name = "Birthday"
    dgv1.Columns(5).DataPropertyName = "Birthday"
    dgv1.Columns(6).Name = "Age"
    dgv1.Columns(6).DataPropertyName = "Age"
    dgv1.Columns(7).Name = "ContactNumber"
    dgv1.Columns(7).DataPropertyName = "TelNum"
    dgv1.DataSource = dt
End Using

这里的问题是当我使用FilterData代码并再次选择ShowRecord代码时。它在这一行引发错误：

dgv1.ColumnCount = 8

说

  

无法在数据绑定的datagridview上设置columncount属性   控制

任何人都可以帮我解决这个问题。感谢