访问 GridView 控件内的不同控件

引言

我收到很多邮件询问如何访问位于 GridView 控件内的特定控件。 在本文中，我将向您展示如何访问 GridView 控件内的不同控件。 我们将看到如何访问 TextBox 控件、DropDownList 控件和 ListBox 控件。 如果您正在使用 ASP.NET 1.X，那么您可能需要查看我的文章 访问 DataGrid 控件内的不同控件。

将控件添加到 GridView 控件

您可以通过简单地使用 <ItemTemplate> 选项将多个控件添加到 GridView 控件。

填充 ListBox 和 DropDownList

接下来的任务是填充 ListBox 和 DropDownList 控件。 让我们创建一个简单的服务器端方法来填充 ListBox 和 DropDownList。

C# 代码

// This method populates the DropDownList and the ListBox control
public DataSet PopulateControls()
{
    SqlConnection myConnection = new SqlConnection(GetConnectionString());
    SqlDataAdapter ad = new SqlDataAdapter("SELECT [Name] FROM tblPerson", 
                                                            myConnection);
    DataSet ds = new DataSet();
    ad.Fill(ds, "tblPerson");
    return ds;
}

VB.NET 代码

' This method populates the DropDownList and the ListBox control
Public Function PopulateControls() As DataSet
    Dim myConnection As SqlConnection = New SqlConnection(GetConnectionString())
    Dim ad As SqlDataAdapter = New SqlDataAdapter("SELECT " & _ 
                               "[Name] FROM tblPerson",myConnection)
    Dim ds As DataSet = New DataSet()
    ad.Fill(ds, "tblPerson")
    Return ds
End Function

现在我们需要在 HTML 视图中绑定此方法。 请查看 DropDownList 的以下代码，您可以对 ListBox 控件重复相同的过程。

<ItemTemplate>
  <asp:DropDownList ID="DropDownList1" DataTextField="Name" 
    DataValueField = "Name" DataSource= '<%# PopulateControls() %>' runat="server">
  </asp:DropDownList>
</ItemTemplate>

现在您的 DropDownList 和 ListBox 控件已填充了一些数据。 现在让我们看看如何访问 GridView 内部的不同控件。

访问 GridView 控件内的不同控件

在 Button 点击事件中，我们将尝试打印出输入（TextBox）或选择（DropDownList 和 ListBox）的值。 让我们看看如何做到这一点。

C# 代码

protected void Button1_Click(object sender, EventArgs e)
{
    // Iterates through the rows of the GridView control
    foreach (GridViewRow row in GridView1.Rows)
    {
        // Selects the text from the TextBox
        // which is inside the GridView control
        string textBoxText = _
          ((TextBox)row.FindControl("TextBox1")).Text;
        Response.Write(textBoxText);
        // Selects the text from the DropDownList
        // which is inside the GridView control
        string dropDownListText = ((DropDownList)
           row.FindControl("DropDownList1")).SelectedItem.Value;
        Response.Write(dropDownListText);
        // Selects items from the ListBox
        // which is inside the GridView control
        ListBox myListBox = (ListBox)row.FindControl("ListBox1");

        foreach(ListItem selectedItem in myListBox.Items)
        {
            // Checks if the item in the ListBox is selected or not
            if (selectedItem.Selected)
            {
                // Print the value of the item if its selected
                Response.Write(selectedItem.Value);
            }
        }
    }

VB.NET 代码

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs)
        ' Iterates through the rows of the GridView control
        For Each row As GridViewRow In GridView1.Rows
            ' Selects the text from the TextBox
            ' which is inside the GridView control
            Dim textBoxText As String = _
              CType(row.FindControl("TextBox1"),TextBox).Text
            Response.Write(textBoxText)
            ' Selects the text from the DropDownList
            ' which is inside the GridView control
            Dim dropDownListText As String = _
              CType(row.FindControl("DropDownList1"), _
              DropDownList).SelectedItem.Value
            Response.Write(dropDownListText)
            ' Selects items from the ListBox
            ' which is inside the GridView control 
            Dim myListBox As ListBox = _
                CType(row.FindControl("ListBox1"),ListBox)
            For Each selectedItem As ListItem In myListBox.Items
                ' Checks if the item in the ListBox is selected or not 
                If selectedItem.Selected Then
                    ' Print the value of the item if its selected
                    Response.Write(selectedItem.Value)
                End If
            Next
        Next
    End Sub

我们在上面的代码中所做的一切就是使用 GridViewRow 对象遍历 GridView 控件的所有行。 接下来，我们使用 FindControl 方法找到控件并打印出控件的值。

希望您喜欢这篇文章，祝您编码愉快！