C# 如何从datagridview将数据加载到combobox中

我想以另一种形式将数据从datagridview加载到combobox以进行更新问题是未根据productid在productname combobox中选择特定项解决方案是什么请帮助

// Code of gridview form 

     private void invoiceItemsDetailsDataGridView_DoubleClick(object sender, EventArgs e)
    {
        int index = invoiceItemsDetailsDataGridView.Rows.GetFirstRow(DataGridViewElementStates.Selected);
        //string productid = invoiceItemsDetailsDataGridView.Rows[index].Cells["ProductId"].Value.ToString();
        //string productName = invoiceItemsDetailsDataGridView.Rows[index].Cells["ProductName"].Value.ToString();

        invoiceItemDetailChangeForm icf = new invoiceItemDetailChangeForm();
        icf.CurrentQuantity = Convert.ToUInt16(invoiceItemsDetailsDataGridView.Rows[index].Cells["Quantity"].Value);
        icf.ProductId = Convert.ToUInt16(invoiceItemsDetailsDataGridView.Rows[index].Cells["ProductID"].Value); ;
        icf.ShowDialog();
    }

//要更新的invoiceItemDetailChangeForm中声明的类级别int

    public int CurrentQuantity { get; set; }

    public int ProductId { get; set; }

//与invoiceItemDetailChangeForm表单中的组合框相关的代码

    private void invoiceItemDetailChangeForm_Load(object sender, EventArgs e)
    {
        QtyTextBox.Text = CurrentQuantity.ToString();
        ProductNameComboBox.SelectedValue = ProductId;

        ProductNameComboBox.DisplayMember = "ProductName";
        ProductNameComboBox.ValueMember = "ProductID";
        ProductNameComboBox.DataSource = GetAllProducts();
        //ProductNameComboBox.SelectedValue = -1;

    }

    private object GetAllProducts()
    {
        DataTable dtProducts = new DataTable();
        string connString = ConfigurationManager.ConnectionStrings["dbZ"].ConnectionString;
        using (SqlConnection conn = new SqlConnection(connString))
        {
            using (SqlCommand cmd = new SqlCommand("usp_GetAllProductsForPOS", conn))
            {
                cmd.CommandType = CommandType.Text;
                conn.Open();

                SqlDataReader reader = cmd.ExecuteReader();
                dtProducts.Load(reader);
            }
        }
        return dtProducts;
    }

---

您正在绑定前设置选定值，绑定后必须将其移动

试试这个

private void invoiceItemDetailChangeForm_Load(object sender, EventArgs e)
    {
        QtyTextBox.Text = CurrentQuantity.ToString();


        ProductNameComboBox.DisplayMember = "ProductName";
        ProductNameComboBox.ValueMember = "ProductID";
        ProductNameComboBox.DataSource = GetAllProducts();
        //ProductNameComboBox.SelectedValue = -1;
        ProductNameComboBox.SelectedValue = ProductId;

    }