使gridview响应两个下拉列表 [英] Make gridview respond to two dropdown lists

问题描述

我的页面中有两个下拉列表和一个gridview，我从数据库绑定了一个下拉列表，另一个我直接在页面中列出了列表项，因为在另一个下拉列表中只有5个项目。



现在的问题是我应该能够让gridview响应两个下拉菜单

selectindex更改事件并在gridview中填充它。 ..我没有得到怎么做..



onselectindex事件未触发且数据未进入gridview。



我尝试过：

I have Two dropdowns and one gridview in my page,, i am binding one dropdownlist from database and the other i directly took list items in the page as there are only 5 items in another dropdown.

now the problem is i should be able to make the gridview respond to two dropdowns
in selectindex changed event and populate that in gridview... i am not getting how to do that..

onselectindex event not firing and data is not coming in gridview.

What I have tried:

<asp:DropDownList ID="ddlGroupName" runat="server" CssClass="form-control input-sm" AutoPostBack="true" AppendDataBoundItems="true" OnSelectedIndexChanged="ddlGroup_SelectedIndexChanged">
                       <asp:ListItem Text="All" Value="0"></asp:ListItem>
                   </asp:DropDownList>

<div class="row">
    <div class="col-lg-12">
        <asp:GridView ID="grdDeviceDetails" runat="server" AutoGenerateColumns="false" CssClass="table table-hover table-bordered"
            AllowPaging="true" PagerSettings-PageButtonCount="3" GridLines="None" PageSize="10" OnPageIndexChanging = "OnPaging">
            <Columns>
                <asp:BoundField DataField="GroupName" HeaderText="GroupName" SortExpression="GroupName" />
                <asp:BoundField DataField="Brand" HeaderText="Brand" SortExpression="Brand" />
                <asp:BoundField DataField="Model" HeaderText="Model" SortExpression="Model" />
                <asp:BoundField DataField="SerialNo" HeaderText="SerialNo" SortExpression="SerialNo" />
                <asp:BoundField DataField="Status" HeaderText="Status" SortExpression="Status" />
                <asp:BoundField DataField="AddedOn" HeaderText="Date" SortExpression="AddedOn" />

            </Columns>
            <PagerStyle CssClass="pagination-ys" />
        </asp:GridView>
        </div>
    </div>

 <asp:DropDownList ID="ddlState" runat="server" CssClass="form-control input-sm" AutoPostBack="true" AppendDataBoundItems="true">
                  <asp:ListItem Text="All" Value="All"></asp:ListItem>
<%--                  <asp:ListItem Text="Active" Value="Active"></asp:ListItem>
                  <asp:ListItem Text="Assigned" Value="Assigned"></asp:ListItem>
                  <asp:ListItem Text="Returned" Value="Returned"></asp:ListItem>
                  <asp:ListItem Text="De-activated" Value="De-activated"></asp:ListItem>
                  <asp:ListItem Text="Sent for repair" Value="Sent for repair"></asp:ListItem>
                  <asp:ListItem Text="End of life-retired" Value="End of life-retired"></asp:ListItem>--%>
                  </asp:DropDownList>

public DataSet GetItems()
      {

          SqlConnection con = new SqlConnection(cs);
          SqlCommand cmd = new SqlCommand("sp_DeviceDetails", con);
          cmd.CommandType = CommandType.StoredProcedure;
          SqlDataAdapter da = new SqlDataAdapter(cmd);
          DataSet ds = new DataSet();
          try
          {
              con.Open();
              da.Fill(ds);
              con.Close();
          }
          catch (Exception ex)
          {
              //write error message
          }
          return ds;
      }

        protected void Page_Load(object sender, EventArgs e)
        {
            ddlGroupName.DataSource = GetItems();
            ddlGroupName.DataTextField = "GroupName";
            ddlGroupName.DataBind();
            grdDeviceDetails.DataSource = GetItems();
            grdDeviceDetails.DataBind();
}

protected void ddlGroup_SelectedIndexChanged(object sender, EventArgs e)
{

        GetItems();
}

推荐答案

添加 IsPostBack 条件 PageLoad 事件

Add IsPostBack Condtion in PageLoad event

protected void Page_Load(object sender, EventArgs e)
         {
         if (!Page.IsPostBack)
           {
              ddlGroupName.DataSource = GetItems();
              ddlGroupName.DataTextField = "GroupName";
              ddlGroupName.DataBind();
              grdDeviceDetails.DataSource = GetItems();
              grdDeviceDetails.DataBind();
           }
         }

您需要从 DropDownList传递所选项目 DropDownList 选择过滤 GridView ，请在SQL查询或SP中使用code>。这是一个快速举例供您参考：

You need to pass the selected item from the DropDownList in your sql query or SP if you want to filter GridView based on the DropDownList selection. Here's a quick example for your reference:

<br />
protected void BindGrid(string selectedItem){<br />
    using(SqlConnection connection = new SqlConnection("YOUR CONNECTION STRING HERE")){<br />
                string sql = "SELECT Field1, Field2, Field3 FROM YourTableName WHERE YourFieldName = @Param1";<br />
        using(SqlCommand cmd = new SqlCommand(sql,connection)){<br />
                cmd.Parameters.AddWithValue("@Param1", selectedItem);<br />
<br />
                DataTable dt = new DataTable();<br />
                SqlDataAdapter ad = new SqlDataAdapter(cmd);<br />
                ad.Fill(dt);<br />
<br />
                if (dt.Rows.Count > 0) { //check if the query returns any data<br />
                       GridView1.DataSource = dt;<br />
                       GridView1.DataBind();<br />
                }<br />
                else<br />
                {<br />
                     //No records found<br />
                }<br />
        }<br />
<br />
    }<br />
}<br />

然后在你的下拉菜单的 SelectedIndexChanged 事件中，你可以像这样调用上面的方法：

Then at SelectedIndexChanged event of your dropdown, you can call the method above like this:

<br />
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e){<br />
	 BindGrid(DropDownList1.SelectedItem.Text);<br />
}<br />

只需确保将 AutoPostback 设置为true即可你的下拉列表触发 selectedindexchanged 事件。

Just make sure to set AutoPostback to true for your dropdown to fire the selectedindexchanged event.

我不是ASP.NET程序员（更喜欢MVC），但看起来< asp：DropDownList ID =ddlStaterunat =serverCssClass =form-control input-smAutoPostBack =trueAppendDataBoundItems =true> control没有接通 OnSelectedIndexChanged 事件。

I am not an ASP.NET programmer (prefer MVC), but it appears that <asp:DropDownList ID="ddlState" runat="server" CssClass="form-control input-sm" AutoPostBack="true" AppendDataBoundItems="true"> control is not wired up for the OnSelectedIndexChanged event.

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