GridView中填充下拉列表的方法

Question

如果我想在GridView中填充DropdownList什么将是最好的方法？使用GridView'OnRowDataBound'事件并且每次都提取查询到数据库或首先获取所有数据并将其放在数据表上并从该数据表中继续工作？

Answer 1

由于您的问题不清楚您的要求，我假定您想要使用gridview的OnRowDataBound事件在Gridview内绑定dropdownlist。

所以这里的步骤： -

1. 在你的aspx页面与DropDownList在TemplateFieldItemTemplate添加一个GridView控件的HTML。

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" OnRowDataBound="OnRowDataBound"> 
 
    <Columns> 
 
     <asp:BoundField HeaderText="Name" DataField="ContactName" /> 
 
     <asp:TemplateField HeaderText = "Country"> 
 
      <ItemTemplate> 
 
       <asp:Label ID="lblCountry" runat="server" Text='<%# Eval("Country") %>' Visible = "false" /> 
 
       <asp:DropDownList ID="ddlCountries" runat="server"> 
 
       </asp:DropDownList> 
 
      </ItemTemplate> 
 
     </asp:TemplateField> 
 
    </Columns> 
 
</asp:GridView>

然后，你需要的gridview与将来自于数据库中的记录进行绑定。

protected void Page_Load(object sender, EventArgs e) 
{ 
    if (!IsPostBack) 
    { 
     GridView1.DataSource = GetData("SELECT ContactName, Country FROM Customers"); 
     GridView1.DataBind(); 
    } 
} 
private DataSet GetData(string query) 
{ 
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString; 
    SqlCommand cmd = new SqlCommand(query); 
    using (SqlConnection con = new SqlConnection(conString)) 
    { 
     using (SqlDataAdapter sda = new SqlDataAdapter()) 
     { 
      cmd.Connection = con; 
      sda.SelectCommand = cmd; 
      using (DataSet ds = new DataSet()) 
      { 
       sda.Fill(ds); 
       return ds; 
      } 
     } 
    } 
} 

然后为OnRowDataBound代码将遵循如下图所示： -

protected void OnRowDataBound(object sender, GridViewRowEventArgs e) 
{ 
    if (e.Row.RowType == DataControlRowType.DataRow) 
    { 
     //Find the DropDownList in the Row 
     DropDownList ddlCountries = (e.Row.FindControl("ddlCountries") as DropDownList); 
     ddlCountries.DataSource = GetData("SELECT DISTINCT Country FROM Customers"); 
     ddlCountries.DataTextField = "Country"; 
     ddlCountries.DataValueField = "Country"; 
     ddlCountries.DataBind(); 

     //Add Default Item in the DropDownList 
     ddlCountries.Items.Insert(0, new ListItem("Please select")); 

     //Select the Country of Customer in DropDownList 
     string country = (e.Row.FindControl("lblCountry") as Label).Text; 
     ddlCountries.Items.FindByValue(country).Selected = true; 
    } 
} 

供您参考，请参阅Reference link

另见Working demo供您参考

希望有所帮助。