asp.net的ListView排序使用的DataBind [英] asp.net ListView Sorting using DataBind

问题描述

排序列表视图中使用的列标题在LayoutTemplate模板

我能够排序采用asp基本列表视图：SqlDataSource和它所指向的asp设置列表视图属性的DataSourceID：SqlDataSource的ID。我当不使用ASP排序时，有一个问题：SqlDataSource和从code仅仅落后绑定

I am able to sort a basic list view using asp:SqlDataSource and setting the list view property DataSourceID by pointing it to the asp:SqlDataSource ID. I am having an issue when sorting when not using the asp:SqlDataSource and just DataBinding from the code behind.

SqlDataSource的例子：

<asp:ListView ID="ContactsListView" DataSourceID="ContactsDataSource" runat="server">
    <LayoutTemplate>
        <table width="640px" runat="server">
            <tr class="header" align="center" runat="server">
                <td>
                    <asp:LinkButton runat="server" ID="SortByFirstNameButton" CommandName="Sort" Text="First Name" CommandArgument="FirstName" />
    </LayoutTemplate>
    ....
</asp:ListView>

<asp:SqlDataSource ID="ContactsDataSource" runat="server" 
    ConnectionString="<%$ ConnectionStrings:MainConnString %>"
    SelectCommand="SELECT * FROM TableName">
</asp:SqlDataSource>

的DataBind示例：

<asp:ListView ID="ContactsListView" DataSourceID="ContactsDataSource" runat="server">
    <LayoutTemplate>
        <table width="640px" runat="server">
            <tr class="header" align="center" runat="server">
                <td>
                    <asp:LinkButton runat="server" ID="SortByFirstNameButton" CommandName="Sort" Text="First Name" CommandArgument="FirstName" />
    </LayoutTemplate>
    ....
</asp:ListView>

protected void Page_Load(object sender, EventArgs e)
{
    String SQL = "SELECT * FROM Customer";
    SqlDataAdapter da= new SqlDataAdapter(SQL, ConnStr);
    DataSet ds = new DataSet();
    da.Fill(ds);

    ContactsListView.DataSource = ds.Tables[0];
    ContactsListView.DataBind();
}

两个code样品填充列表视图中，但第二个实施例的数据绑定不用于排序工作。与第一实施例中，排序只是工作与加入的asp：LinkBut​​ton的在LayoutTemplate模板中添加的CommandName =排序和设置CommandArugment =的ColumnName，但它不与第二示例工作

Both code samples populate the list view, but the second example data binding does not work for sorting. With the first example, the sorting just works with the added asp:LinkButton in the LayoutTemplate adding the CommandName="sort" and setting the CommandArugment="ColumnName", but it does not work with the second example.

任何人都可以请解释为何以及如何获得排序使用背后DataBind方法的code工作？

Can anyone please explain why and how to get the sorting working using the code behind DataBind method?

谢谢！

推荐答案

我解决了我的问题。

我添加了一个事件来处理排序。事件抓起命令名（数据列），并把它和排序方向成一个函数，这将使另一个调用数据库返回的结果进行排序，并重新绑定到列表视图。

I added an event to handle the sorting. The event grabs the command name (Data column) and passes it and the sorting direction into a function which will make another call to the database sort the returned results and rebind to the List View.

我要创建一个视图状态保持列表视图排序方向，因为某些原因，onsorting事件处理口口声声说排序方向呈上升趋势。

I had to create a view state to hold the List View Sort Direction because for some reason, the onsorting event handler kept saying that the sort direction was ascending.

前端

<asp:ListView ID="ContactsListView" OnSorting="ContactsListView_Sorting" runat="server">
    <LayoutTemplate>
        <table width="640px" runat="server">
            <tr class="header" align="center" runat="server">
                <td>
                    <asp:LinkButton runat="server" ID="SortByFirstNameButton" CommandName="Sort" Text="First Name" CommandArgument="FirstName" />
    </LayoutTemplate>
    ....
</asp:ListView>

后端

protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        BindContacts(string.Empty);
    }
}

protected SortDirection ListViewSortDirection
{
    get
    {
        if (ViewState["sortDirection"] == null)
            ViewState["sortDirection"] = SortDirection.Ascending;
        return (SortDirection)ViewState["sortDirection"];
    }
    set { ViewState["sortDirection"] = value; }
}

protected void ContactsListView_Sorting(Object sender, ListViewSortEventArgs e)
{
    BindContacts(e.SortExpression + " " + ListViewSortDirection.ToString());

    // Check the sort direction to set the image URL accordingly.
    string imgUrl;
    if (ListViewSortDirection == SortDirection.Ascending)
        ListViewSortDirection = SortDirection.Descending;
    else
        ListViewSortDirection = SortDirection.Ascending;
}

private void BindContacts(string sortExpression)
{
    sortExpression = sortExpression.Replace("Ascending", "ASC");
    sortExpression = sortExpression.Replace("Descending", "DESC");
    using (SqlConnection conn = new SqlConnection(_connStr))
    {
        conn.Open();
        using (SqlDataAdapter dAd = new SqlDataAdapter("SELECT * FROM Customer", conn))
        {
            DataTable dTable = new DataTable();
            dAd.Fill(dTable);
            // Sort now
            dTable.DefaultView.Sort = sortExpression;
            // Bind data now
            ContactsListView.DataSource = dTable;
            ContactsListView.DataBind();
        }
        conn.Close();
    }
}

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