Question

我有一个列表视图加载页面，但我想隐藏一个带条件的按钮。

我收到此错误消息对象引用未设置为对象的实例。

甚至认为commandName有一个值。代码在listview数据绑定下。

这是我的代码：

protected void PostListView_ItemDataBound(object sender, ListViewItemEventArgs e)
    {

        if (e.Item == null)
            return;

        MembershipUser currentUser = Membership.GetUser();
        Guid currentUserId = (Guid)currentUser.ProviderUserKey;
        Button btn1 = (Button)e.Item.FindControl("deleteButton");

        if (currentUserId.ToString() == btn1.CommandName.ToString())
        {
            Button hdn = (Button)e.Item.FindControl("deleteButton");
            btn1.Visible = false;
        }

        else
        {
            Button hdn = (Button)e.Item.FindControl("deleteButton");
            btn1.Visible = false;
        }
    }



<asp:ListView ID="PostListView" runat="server" DataSourceID="POSTDataSource2" OnItemDataBound="PostListView_ItemDataBound" OnLoad="PostListView_Load">
                                <AlternatingItemTemplate>

                                    <p class="text-muted">
                                                    <asp:Button ID="deleteButton" runat="server" Text="Delete" CssClass="btn btn-info btn-xs pull-right" Width="50px" CommandName='<%# Eval("UserId") %>'  />
                                    </p>
                                </AlternatingItemTemplate>

Answer 1

您必须查看ItemDataBound中的ItemType：

protected void PostListView_ItemDataBound(object sender, ListViewItemEventArgs e)
{
    if (e.Item.ItemType == ListViewItemType.DataItem)
    {
        MembershipUser currentUser = Membership.GetUser();
        Guid currentUserId = (Guid)currentUser.ProviderUserKey;
        Button btn1 = (Button)e.Item.FindControl("deleteButton");

        if (currentUserId.ToString() == btn1.CommandName.ToString())
        {
            Button hdn = (Button)e.Item.FindControl("deleteButton");
            btn1.Visible = false;
        }

        else
        {
            Button hdn = (Button)e.Item.FindControl("deleteButton");
            btn1.Visible = false;
        }
    }
}

对象引用未设置为具有listview数据绑定的对象的实例

1 个答案: