Checkbox == true未检测到

Question

我目前正在尝试通过复选框从列表视图中删除一行(或多行).我的代码如下所示.我在网站的类似区域使用了相同的代码但是这个代码似乎不起作用.勾选复选框,按下删除按钮,它只是重新加载页面而不删除.

页面加载

protected void Page_Load(object sender, EventArgs e)
{
    DSTableAdapters.contact_messagesTableAdapter cmta = new DSTableAdapters.contact_messagesTableAdapter();
    DSTableAdapters.messagesTableAdapter mta = new DSTableAdapters.messagesTableAdapter();
    DSTableAdapters.user_messagesTableAdapter umta = new DSTableAdapters.user_messagesTableAdapter();

    DataTable cMessageTable = cmta.GetAll();
    DataTable ownerMessagesTable = umta.GetMessages("owner");
    DataTable clientMessagesTable = umta.GetMessages("user");

    lvContact.DataSource = cMessageTable;
    lvContact.DataBind();

    lvClientMessages.DataSource = clientMessagesTable;
    lvClientMessages.DataBind();

    lvOwnerMessages.DataSource = ownerMessagesTable;
    lvOwnerMessages.DataBind();
}

标记:

   <asp:ListView ID="lvContact" runat="server" DataKeyNames="contact_id">
      <LayoutTemplate>
        <table id="itemPlaceHolderContainer">
          <tr>
            <th>Message ID</th>
            <th>Email Address</th>
            <th>Message</th>
            <th>Date</th>
          </tr>
          <tr runat="server" id="itemPlaceHolder"></tr>
        </table>
      </LayoutTemplate>
      <ItemTemplate>
        <tr>
          <td>
            <asp:CheckBox ID="chkContactID" runat="server" AutoPostBack="false" />
          </td>
          <td>
            <asp:Label ID="lblContactEmail" runat="server" Text='<%#Eval("email") %>' />
          </td>
          <td>
            <asp:Label ID="lblContactMessage" runat="server" Text='<%#Eval("message") %>' />
          </td>
          <td>
            <asp:Label ID="lblContactDate" runat="server" Text='<%#Eval("date") %>' />
          </td>
        </tr>
      </ItemTemplate>
    </asp:ListView>
    <asp:Button ID="btnContactDelete" runat="server" 
    Text="Delete Selected Messages" onclick="btnContactDelete_Click" />

代码隐藏:

protected void btnContactDelete_Click(object sender, EventArgs e)
{
    // Loop through each row to find checked boxes
    for (int i = 0; i < lvContact.Items.Count; i++)
    {
        ListViewDataItem items = lvContact.Items[i];
        int iContactID = Convert.ToInt16(lvContact.DataKeys[items.DataItemIndex]["contact_id"]);
        CheckBox chkBox = (CheckBox)items.FindControl("chkContactID");
        if (chkBox.Checked == true)
        {
            Response.Write(iContactID);
            // If selected to be deleted
            DSTableAdapters.contact_messagesTableAdapter cmta = new DSTableAdapters.contact_messagesTableAdapter();
            cmta.DeleteMessage(iContactID);
        }
    }
    lvContact.DataBind();
}

Answer 1

您是否在页面加载中填充ListView,您可能需要

if (!IsPostBack)
{
     //Fill ListView
}

我认为当网页发回帖子时,你会丢失选中的复选框.