ASP.NET C＃中的“编辑/删除”按钮

Question

I have a form that lists customers pulled from a db. The form also consists of edit and delete buttons in order to update an existing customer's record. I am able to pull back all the table data for the customers on the first page. However, when I click the "Edit" button next to a customer it does not bring back any data but just brings back a blank form. I am referencing the CustomerID in the "Edit" hyperlink with a NavigateURL link. I have read and read and am getting confused about how to do this. Can anyone see what I may be doing wrong? Getting very frustrated. Please help.

<div>
    <h2>Customer Listing</h2>
    <br />
</div>

<p style="text-align:center">
    <asp:Button ID="btnCustomer" class="button" runat="server" Text="Add New Customer" onclick="btnCustomer_Click" />
</p>


<asp:ListView ID="lv" runat="server" 
    onselectedindexchanged="lv_SelectedIndexChanged">
<LayoutTemplate>
  <table width="110%" class="TableListing">
  <tbody>
    <thead>
    <th width="150">Customer Name</th>
      <th width="150">Email</th>
      <th width="150">City</th>
      <th width="40">State</th>
      <th width="110">Phone</th>
      <th width="80">Modify</th>
    </thead>
    <tr id="itemPlaceholder" runat="server"></tr>
     </tbody>
    </table>  

    <asp:DataPager ID="ItemDataPager" runat="server" PageSize="20">
        <Fields>
            <asp:NumericPagerField ButtonCount="5" />
        </Fields>
    </asp:DataPager>

</LayoutTemplate>

<ItemTemplate>
    <tr>
     <td><%# Eval ("LastName") %>, <%# Eval ("FirstName") %></td>
     <td><%# Eval ("Email") %></td>
     <td><%# Eval ("City") %></td>
     <td><%# Eval ("State") %></td>
     <td><%# Eval ("Phone") %></td>
     <td>
        <asp:HyperLink ID="lnkEdit" runat="server" NavigateUrl='<%# "CustomerEdit.aspx?ID=" + Eval("CustomerID") + Request.QueryString["LastName"] + Eval("LastName") %>' Text="Edit" />
    </td>
    </tr>
</ItemTemplate>

I then redirect to the CustomerEdit page:

    protected void Page_Load(object sender, EventArgs e)
    {
        this.Master.HighlightNavItem("Customers");

        int CustomerID = 0;


        //Declare the connection object
        SqlConnection Conn = new SqlConnection();
        Conn.ConnectionString = ConfigurationManager.ConnectionStrings["MyDatabase"].ConnectionString;

        //Connect to the db
        Conn.Open();

    //Define query
        string sql = "SELECT * FROM Customer where CustomerID=@CustomerID";

    //Declare the Command
    SqlCommand cmd = new SqlCommand(sql, Conn);

    //Add the parameters needed for the SQL query
    //cmd.Parameters.AddWithValue("@LastName", LastName);

    //Declare the DataReader
    SqlDataReader dr = null;

    //Fill the DataReader
    dr = cmd.ExecuteReader();

    //Get the data
    if (dr.Read() == false)
    {
        //No Records
        dr.Close();
        Conn.Close();
        return;
    }

    txtFirstName.Text = dr["FirstName"].ToString();
    txtLastName.Text = dr["LastName"].ToString();

    dr.Close();
    Conn.Close();


    }


    protected void btnCancel_Click1(object sender, EventArgs e)
    {
        Response.Redirect("Customers.aspx");
    }

    protected void btnUpdate_Click(object sender, EventArgs e)
    {

        //Declare the connection object
        SqlConnection Conn = new SqlConnection();
        Conn.ConnectionString = ConfigurationManager.ConnectionStrings["MyDatabase"].ConnectionString;

        //Connect to the db
        Conn.Open();

        //Define query
        string sql = "INSERT INTO Customer (FirstName, LastName, Email, Password, Address1, Address2, City, State, Zip, Phone, Fax) VALUES (@FirstName, @LastName, @Email, @Password, @Address1, @Address2, @City, @State, @Zip, @Phone, @Fax)";
        //sql = "INSERT INTO xSample(Region,RepName,...) VALUES(@Region,@RepName,...)


        //Declare the Command
        SqlCommand cmd = new SqlCommand(sql, Conn);

        //Add the parameters needed for the SQL query
        cmd.Parameters.AddWithValue("@FirstName", txtFirstName.Text);
        cmd.Parameters.AddWithValue("@LastName", txtLastName.Text);
        cmd.Parameters.AddWithValue("@Email", txtEmail1.Text);
        cmd.Parameters.AddWithValue("@Password", txtPassword1.Text);
        cmd.Parameters.AddWithValue("@Address1", txtAddress1.Text);
        cmd.Parameters.AddWithValue("@Address2", txtAddress2.Text);
        cmd.Parameters.AddWithValue("@City", txtCity.Text);
        cmd.Parameters.AddWithValue("@State", txtState.Text);
        cmd.Parameters.AddWithValue("@Zip", txtZip.Text);
        cmd.Parameters.AddWithValue("@Phone", txtPhone.Text);
        cmd.Parameters.AddWithValue("@Fax", txtFax.Text);

        //Execute the query
        int NumRows = 0;
        NumRows = cmd.ExecuteNonQuery();

        Conn.Close();

        lblUpdate.Text = "Updated " + NumRows.ToString() + " record";

    }

}

}

Answer 1

In your page_load of the custmeredit.aspx

replace this:

int CustomerID = 0;

with:

int CustomerID = Int32.Parse(Request.QueryString["ID"]);