Findcontrol Listview编辑-NullreferenceException [英] Findcontrol Listview Edit - NullreferenceException

问题描述

我有一个很奇怪的问题.我有一个可编辑的ListView，但是-单击编辑"时，通常在尝试获取文本框后通常会收到NullreferenceException.但是错误是不一致的，有时它在那里，有时不是.我很困惑.

I have a rather odd problem. I have an editable ListView, however - when I click edit I usually get the NullreferenceException once I try to get the textboxes. BUT the error is not consistent, sometimes it is there, sometimes not. I'm confused.

这是代码段:

public void test_ItemEditing(Object sender, ListViewEditEventArgs e)
{

    // Liest die SpeiseID mit der die Daten aus der Datenbank extrahiert werden können
    DataKey currentDataKey = speiseplanListView.DataKeys[e.NewEditIndex];

    TextBox editDatum  = (TextBox)speiseplanListView.EditItem.FindControl("txtDatum");


}

这是asp.net文件:

this is the asp.net file:

<EditItemTemplate>
    <tr>
        <td><asp:TextBox ID="txtDatum" runat="server"></asp:TextBox></td>
        <td><asp:TextBox ID="txtSpeise" runat="server"></asp:TextBox></td>

    </tr>
</EditItemTemplate>

推荐答案

用下面的一个替换您的 test_ItemEditing 代码

replace your test_ItemEditing code with below one

public void test_ItemEditing(Object sender, ListViewEditEventArgs e)
{
    lvEmployee.EditIndex = e.NewEditIndex;

    test.DataSource = GetData("Select * from Table");

    test.DataBind();
}

并处理 test_ItemUpdating 事件以查找控件并更新数据.

and handle the test_ItemUpdating event for finding the control and updating the data.

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