我在通过vb.net删除mysql数据库中的行时遇到问题

Question

错误不断弹出“对象引用未设置为对象的实例 如果DataGridView1.RowCount = 0，则 MsgBox（“无法删除，表数据为空”，MsgBoxStyle.Critical，“错误消息”） 返回 如果结束

    If DataGridView1.SelectedRows.Count = 0 Then
        MsgBox("Cannot delete, select the table data to be deleted", MsgBoxStyle.Critical, "Error Message")
        Return
    End If

    If MsgBox("Delete record?", MsgBoxStyle.Question + MsgBoxStyle.OkCancel, "Confirmation") = MsgBoxResult.Cancel Then Return

    Try
        con.Open()
    Catch ex As Exception
        MessageBox.Show("Connection failed !!!" & vbCrLf & "Please check that the server is ready !!!", "Error Message", MessageBoxButtons.OK, MessageBoxIcon.Error)
        Return
    End Try

    Try
        If AllCellsSelected(DataGridView1) = True Then
            cmd.CommandType = CommandType.Text
            cmd.CommandText = "DELETE FROM animal_sale"
            cmd.Connection = con
            cmd.ExecuteNonQuery()
        End If

        For Each row As DataGridViewRow In DataGridView1.SelectedRows
            If row.Selected = True Then
                cmd.CommandType = CommandType.Text
                cmd.CommandText = "DELETE * FROM 'animal_sale' WHERE Species='" & row.DataBoundItem(1).ToString & "'"
                cmd.Connection = con
                cmd.ExecuteNonQuery()
            End If
        Next
    Catch ex As Exception
        MsgBox("Failed to delete" & vbCr & ex.Message, MsgBoxStyle.Critical, "Error Message")
        con.Close()
    End Try