GridView更新按钮执行更新SQL Server存储过程

Question

SQL Server stored procedure accepts the parameters, current company name, new company name and whether it already exists which has a default value. When the edit button is clicked on the front end UI, the grid view allows me to edit the company name. This shows an 'Update' button - when this is clicked - the code parses however nothing updates and company name does not update either.

Breakpoint is set and stepped through and @CurrentCompanyName is returned as null. Not sure how to fix this.

Aspx:

<asp:GridView ID="CompanyTable" runat="server" 
     OnRowEditing="CompanyTable_RowEditing" 
     OnRowCancelingEdit="CompanyTable_RowCancelingEdit" 
     OnRowUpdating="CompanyTable_RowUpdating" 
     OnPageIndexChanging="CompanyTable_PageIndexChanging" 
     PageSize="20" Font-Underline="False" AllowPaging="True">
    <HeaderStyle Width="150px" />
    <Columns>
        <asp:TemplateField>
            <HeaderStyle Width="200px" />
            <ControlStyle CssClass="ButtonDesigntwo" />
            <ItemTemplate>
                <asp:LinkButton ID="Edit" ButtonType="Button" runat="server" CommandName="Edit" Text="Edit" />
                <asp:LinkButton ID="Delete" ButtonType="Button" runat="server" CommandName="Delete" Text="Delete" />
            </ItemTemplate>
            <EditItemTemplate>  
                <asp:Button ID="Update" ButtonType="Button" runat="server" Text="Update" CommandName="Update"/>  
                <asp:Button ID="Cancel" ButtonType="Button" runat="server" Text="Cancel" CommandName="Cancel"/>  
            </EditItemTemplate>   
        </asp:TemplateField>
    </Columns>
    <HeaderStyle CssClass="tableHeaderStyle" />
    <PagerSettings Mode="NumericFirstLast" />
    <PagerStyle CssClass="pager" BorderColor="Black" ForeColor="White" Font-Underline="False" />
    <RowStyle CssClass="tableRowStyle" />
</asp:GridView>

Method code:

 protected void CompanyTable_RowUpdating(object sender, System.Web.UI.WebControls.GridViewUpdateEventArgs e)
 {
        string connectionString = ConfigurationManager.ConnectionStrings["DBConnection"].ConnectionString;

        SqlConnection cn = new SqlConnection(connectionString);

        using (SqlCommand cmd = new SqlCommand("[updateCompanyName]", cn))
        {
            TextBox name = CompanyTable.Rows[e.RowIndex].FindControl("CompanyTable") as TextBox;
            cmd.CommandType = CommandType.StoredProcedure;

            cmd.Parameters.AddWithValue("@CurrentCompanyName", name);
            cmd.Parameters.AddWithValue("@NewCompanyName", CompanyInputTextBox.Text).Direction = ParameterDirection.Input;

            SqlParameter objisExists = new SqlParameter("@isExists", SqlDbType.Int);
            objisExists.Direction = ParameterDirection.Output;
            cmd.Parameters.Add(objisExists);

            cn.Open();
            cmd.ExecuteNonQuery();
            cn.Close();

            int isExists = Convert.ToInt32(cmd.Parameters["@isExists"].Value.ToString());

            if (isExists == 0)
            {
                Page.ClientScript.RegisterStartupScript(this.GetType(), "111", "AddCompanyUpdating();", true);
            }
            else if (isExists == 1)
            {
                Page.ClientScript.RegisterStartupScript(this.GetType(), "111", "CompanyNotUpdatedValidation();", true);
            }
        }

        // Setting the EditIndex property to -1 to cancel the Edit mode in Gridview  
        CompanyTable.EditIndex = -1;

        // Call ShowData method for displaying updated data  
        BindData();
    }

Stored procedure:

ALTER PROCEDURE [dbo].[updateCompanyName] 
    @CurrentCompanyName VARCHAR(50),
    @NewCompanyName VARCHAR(50),
    @IsExists INT = 0 OUT 
AS 
BEGIN
    DECLARE @CompanyID INT

    SELECT @CompanyID = CompanyID 
    FROM company 
    WHERE companyname = @CurrentCompanyName

    BEGIN
        IF EXISTS (SELECT CompanyName 
                   FROM company 
                   WHERE companyname = @NewCompanyName )
        BEGIN
            SET @IsExists = 1
        END
        ELSE
        BEGIN   
            UPDATE COMPANY
            SET CompanyName = @NewCompanyName 
            WHERE companyid = @CompanyID

            SET @IsExists = 0
        END
    END

    PRINT @isexists 
END

Answer 1

You are defining name as a textbox in this line:

TextBox name = CompanyTable.Rows[e.RowIndex].FindControl("CompanyTable") as TextBox;

Then you try to set the value of your parameter to the textbox in this line:

cmd.Parameters.AddWithValue("@CurrentCompanyName", name);

When what you SHOULD be doing, is setting the parameter value to the TEXT that is IN the textbox:

cmd.Parameters.AddWithValue("@CurrentCompanyName", name.Text);

EDIT:

Since name itself is NULL when you are hovering over it, that means that you have not correctly defined it in this line:

TextBox name = CompanyTable.Rows[e.RowIndex].FindControl("CompanyTable") as TextBox;

Stop the code in the debugger and open a quick view into CompanyTable, and see if you can figure out the correct way to define the textbox you are looking for.

EDIT 2: In defining your TextBox, you are doing FindControl("CompanyTable") , but according to your markup, "CompanyTable" is the ID of your GridView, not a textbox. In fact, I don't see any markup anywhere for a textbox in the first code sample you posted.