[英]how can i add items which are checked to arraylist in Gridview c# asp.net
[英]asp.net c# send ArrayList to gridview not displaying items
我有3個下拉列表: select year
, select make
, select model
。 選擇模型后,結果應顯示在gridview中。 我的表是:用[(pk)MakeID, MakeName];
具有[(pk)ModelID, Make_ID, ModelYear, ModelName];
和具有[(pk)WiperID, Model_ID, Description, Emplacement, Price]
。 當我逐步調試時,我發現找到了6條記錄,但是在gridview中卻看不到
我已經看過這些尋求幫助,但沒有答案
ASP.net DropDownList填充GridView
使用arraylist asp.net/c#綁定GridView
我的Default.aspx
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<div id="wrapper" align="center">
<asp:DropDownList ID="ddlYear" runat="server"
AutoPostBack="true" OnSelectedIndexChanged="Year_Changed">
</asp:DropDownList>
<asp:DropDownList ID="ddlMake" runat="server"
AutoPostBack="true" OnSelectedIndexChanged="Make_Changed">
</asp:DropDownList>
<asp:DropDownList ID="ddlModel" runat="server"
AutoPostBack="true"
OnSelectedIndexChanged="Get_Wipers_By_Model">
</asp:DropDownList>
</div>
</ContentTemplate>
</asp:UpdatePanel>
<asp:GridView ID="grdWiperList" runat="server">
</asp:GridView>
</form>
我的Default.aspx.cs
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
//Year drop down list is populated on page load
string query = "SELECT DISTINCT ModelYear FROM Models";
string connectionString = ConfigurationManager.ConnectionStrings["wiperConnectionString"].ToString();
SqlCommand cmd = new SqlCommand(query);
using (SqlConnection conn = new SqlConnection(connectionString))
{
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = conn;
conn.Open();
ddlYear.DataSource = cmd.ExecuteReader();
ddlYear.DataValueField = "ModelYear";
ddlYear.DataBind();
conn.Close();
}
}
ddlYear.Items.Insert(0, new ListItem("Select Year", "0"));
ddlMake.Enabled = false;
ddlModel.Enabled = false;
ddlMake.Items.Insert(0, new ListItem("Select Make", "0"));
ddlModel.Items.Insert(0, new ListItem("Select Model", "0"));
}
}
private void BindDropDownList(DropDownList ddl, string query, string text, string value, string defaultText)
{
string connectionString = ConfigurationManager.ConnectionStrings["wiperConnectionString"].ToString();
SqlCommand cmd = new SqlCommand(query);
using (SqlConnection conn = new SqlConnection(connectionString))
{
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = conn;
conn.Open();
ddl.DataSource = cmd.ExecuteReader();
ddl.DataTextField = text;
ddl.DataValueField = value;
ddl.DataBind();
conn.Close();
}
}
ddl.Items.Insert(0, new ListItem(defaultText, "0"));
}
protected void Year_Changed(object sender, EventArgs e)
{
//the Makes drop down list is populated on OnSelectedIndexChange event of the Year_Changed event
ddlMake.Enabled = false;
ddlModel.Enabled = false;
ddlMake.Items.Clear();
ddlModel.Items.Clear();
ddlMake.Items.Insert(0, new ListItem("Select Make", "0"));
ddlModel.Items.Insert(0, new ListItem("Select Model", "0"));
int yearId = int.Parse(ddlYear.SelectedItem.Value);
if (yearId > 0)
{
string query = string.Format("SELECT DISTINCT MakeID, MakeName FROM Makes JOIN Models ON Make_ID = MakeID WHERE ModelYear = {0}", yearId);
BindDropDownList(ddlMake, query, "MakeName", "MakeID", "Select Make");
ddlMake.Enabled = true;
}
}
protected void Make_Changed(object sender, EventArgs e)
{
ddlModel.Enabled = false;
ddlModel.Items.Clear();
ddlModel.Items.Insert(0, new ListItem("Select Model", "0"));
int yearID = int.Parse(ddlYear.SelectedItem.Value);
int makeId = int.Parse(ddlMake.SelectedItem.Value);
if (makeId > 0)
{
string query = string.Format("SELECT ModelID, ModelName FROM Models WHERE ModelYear = {0} AND Make_ID = {1}", yearID, makeId);
BindDropDownList(ddlModel, query, "ModelName", "ModelID", "Select Model");
ddlModel.Enabled = true;
}
}
protected void Get_Wipers_By_Model(object sender, EventArgs e)
{
grdWiperList.DataSource = Connection.GetWipersByModel
(!IsPostBack ? "%" : ddlModel.SelectedValue);
grdWiperList.DataBind();
}
}
我的Connection.cs
public static ArrayList GetWipersByModel(string modelType)
{
ArrayList listResults = new ArrayList();
string query = string.Format
("SELECT * FROM Wipers WHERE Model_ID LIKE '{0}'", modelType);
try
{
conn.Open();
cmd.Connection = conn;
cmd.CommandText = query;
SqlDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
int wiperID = reader.GetInt32(0);
int model_id = reader.GetInt32(1);
string description = reader.GetString(2);
string itemNo = reader.GetString(3);
string emplacement = reader.GetString(4);
decimal price = reader.GetDecimal(5);
Wipers wipers = new Wipers(wiperID, model_id, description, itemNo, emplacement, price);
listResults.Add(wipers);
}
}
finally
{
conn.Close();
}
return listResults;
}
我認為這是因為updatePanel控件嘗試在UpdatePanel控件和DropDownList控件之間添加觸發器
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