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ASP.net update DropDownList

I'm adding a value database table then i want to show on DropDownList. This code working when page is loading. But when i add new value to db, dropdownlist doesn't update. I called after adding value but doesn't change. When i don't use !IsPostBack, dropdownlist updating but in this case DataValueField doesnt working.
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
.............
listStudent.DataSource = dt;
listStudent.DataTextField = "st";
listStudent.DataValueField = "id";
listStudent.DataBind();
}

Well, you are free to put the DataTextField and the DataValue field in the markup.
(but does not matter one bit at all).
So, say we have this markup:
(drop down, and a button to add a new value).
<asp:DropDownList ID="cboHotels" runat="server"
DataValueField="HotelName" DataTextField="HotelName" AutoPostBack="True" Width="174px" >
</asp:DropDownList>
<asp:Button ID="cmdAdd" runat="server" Text="+" style="margin-left:10px"
OnClick="cmdAdd_Click"
OnClientClick="return AddHotel();" />
<asp:TextBox ID="txtHotelName" runat="server" ClientIDMode="Static" style="display:none"></asp:TextBox>
<script>
function AddHotel() {
myhotel = prompt("Enter New Hotel Name")
if (myhotel != null) {
document.getElementById('txtHotelName').value = myhotel
return true
}
else {
return false
}
}
</script>
So, we have that "+" button beside the drop to add a new row to the database.
So, our code to fill the drop down looks like this:
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack == false)
LoadCombo();
}
public void LoadCombo()
{
using (SqlCommand cmdSQL = new SqlCommand("SELECT HotelName from tblHotels ORDER BY HotelName",
new SqlConnection(Properties.Settings.Default.TEST4)))
{
cmdSQL.Connection.Open();
cboHotels.DataSource = cmdSQL.ExecuteReader();
cboHotels.DataBind();
// add a blank (no select row)
cboHotels.Items.Insert(0, new ListItem(""));
}
}
And our code to add a new row looks like this:
protected void cmdAdd_Click(object sender, EventArgs e)
{
// add a new hotel to table
using (SqlCommand cmdSQL =
new SqlCommand("INSERT into tblHotels (HotelName) Values(#Hotel)",
new SqlConnection(Properties.Settings.Default.AccessDB)))
{
cmdSQL.Connection.Open();
cmdSQL.Parameters.Add("#Hotel", SqlDbType.NVarChar).Value = txtHotelName.Text;
cmdSQL.ExecuteNonQuery();
}
LoadCombo(); // re-load combo to show new row
// lets be nice and select the row we just added
cboHotels.ClearSelection();
cboHotels.Items.FindByText(txtHotelName.Text).Selected = true;
}
And we get this:

asp:gridview filter using listbox cannot make multiple selection

I have this asp:gridview in which I show data using mySql stored procedure. I have this listbox named ddlstatus which I use to filter the data. I use viewstate to show data that are selected from the listbox. The problem is I want to make multiple selection on this listbox and show data for each selection made on it, but when it only shows data for the initial selection.
The below is the client side code:
<asp:Label ID="lblstat" Text="status" Visible="false" runat="server"></asp:Label>
<asp:ListBox ID="ddlstatus" runat="server" OnSelectedIndexChanged="DropDownChange" AutoPostBack="true" AppendDataBoundItems="true" SelectionMode="Multiple"></asp:ListBox>
<asp:GridView ID="gdvTM" runat="server" ControlStyle-Width="100%" AutoGenerateColumns="False" DataKeyNames="ID" OnRowDeleting="gdvTM_RowDeleting" PageSize="5" CssClass="cssgridview" AlternatingRowStyle-BackColor="#d5d8dc">
<Columns >
<asp:TemplateField HeaderText="Current Status">
<ItemTemplate >
<asp:Label ID="lblcstat" runat="server" Text='<%# Eval("status") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
The below is the server side code:
private void BindDropDownList()
{
PopulateDropDown(ddlstatus, lblstat.Text);
}
private void PopulateDropDown(ListBox ddl, string columnName)
{
ddl.Items.Clear();
ddl.DataSource = BindDropDown(columnName);
ddl.DataTextField = columnName;
ddl.DataValueField = columnName;
ddl.DataBind();
ddl.Items.Insert(0, new ListItem("Please select", "0"));
}
private void BindGrid()
{
DataTable dt = new DataTable();
String strConnString = System.Configuration.ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
MySqlConnection con = new MySqlConnection(strConnString);
MySqlDataAdapter sda = new MySqlDataAdapter();
MySqlCommand cmd = new MySqlCommand("GetTMData");
cmd.CommandType = CommandType.StoredProcedure;
string statusVal = null;
if (ViewState["stat"] != null && ViewState["stat"].ToString() != "0")
{
statusVal = ViewState["stat"].ToString();
}
cmd.Parameters.AddWithValue("statusVal", statusVal);
cmd.Connection = con;
sda.SelectCommand = cmd;
sda.Fill(dt);
gdvTM.DataSource = dt;
int i = dt.Rows.Count;
gdvTM.DataBind();
this.BindDropDownList();
TableCell cell = gdvTM.HeaderRow.Cells[0];
setDropdownselectedItem(ViewState["stat"] != null ? (string)ViewState["stat"] : string.Empty, ddlstatus);
}
private void setDropdownselectedItem(string selectedvalue, ListBox ddl)
{
if (!string.IsNullOrEmpty(selectedvalue))
{
ddl.Items.FindByValue(selectedvalue).Selected = true;
}
}
protected void DropDownChange(object sender, EventArgs e)
{
ListBox dropdown = (ListBox)sender;
string selectedValue = dropdown.SelectedItem.Value;
switch (dropdown.ID.ToLower())
{
case "ddlstatus":
ViewState["stat"] = selectedValue;
break;
}
this.BindGrid();
}
private DataTable BindDropDown(string columnName)
{
string username = uName.Text;
String strConnString = System.Configuration.ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
MySqlConnection con = new MySqlConnection(strConnString);
MySqlCommand cmd = new MySqlCommand("SELECT DISTINCT (" + columnName + ") FROM approved WHERE tm = #tm AND " + columnName + " IS NOT NULL", con);
MySqlDataAdapter sda = new MySqlDataAdapter(cmd);
cmd.Parameters.AddWithValue("#tm", username);
DataTable dt = new DataTable();
sda.Fill(dt);
return dt;
}
Below is the MySql stored procedure:
CREATE DEFINER=`root`#`localhost` PROCEDURE `GetTMData`(in statusVal varchar(45))
BEGIN
SELECT *
FROM approved
WHERE (statusVal IS NULL
OR status = statusVal)
order by date desc;
END
How can I make this happen? Thanks in advance.

Please make listbox multiple
<asp:ListBox id="ListBox1"
Rows="6"
Width="100px"
**SelectionMode="Multiple"**
runat="server">
<asp:ListItem Selected="True">Item 1</asp:ListItem>
<asp:ListItem>Item 2</asp:ListItem>
<asp:ListItem>Item 3</asp:ListItem>
<asp:ListItem>Item 4</asp:ListItem>
<asp:ListItem>Item 5</asp:ListItem>
<asp:ListItem>Item 6</asp:ListItem>
</asp:ListBox>
Then in server side
void SubmitBtn_Click(Object sender, EventArgs e)
{
Message.Text = "You chose: <br />";
// Iterate through the Items collection of the ListBox and
// display the selected items.
foreach (ListItem item in ListBox1.Items)
{
if(item.Selected)
{
Message.Text += item.Text + "<br />";
}
}
}

First of all, auto post back not allow you to select multiple items because upto select second item, the postback already happens by first selected item so,
You have to set AutoPostBack="false" for your list box,
<asp:ListBox ID="ddlstatus" runat="server" AutoPostBack="false" AppendDataBoundItems="true" SelectionMode="Multiple"></asp:ListBox>
For collecting multiple selected items we simply choose button for instance, you can collect those items wherever you want,
Then add one button that will call below code
<asp:Button ID="button1" runat="server" OnClick="button1_Click" Text="Click"/>
On above button event handler add below code,
protected void button1_Click(object sender, EventArgs e)
{
var selectedNames = ddlstatus.Items.Cast<ListItem>()
.Where(i => i.Selected)
.Select(i => i.Value)
.ToList();
string selectedValue = string.Join("','", selectedNames);
selectedValue = "'" + selectedValue + "'";
ViewState["stat"] = selectedValue;
}
Then the comma separated items in your ViewState will be used in your stored procedure parameter
string statusVal = null;
if (ViewState["stat"] != null && ViewState["stat"].ToString() != "0")
{
statusVal = ViewState["stat"].ToString();
}
cmd.Parameters.AddWithValue("statusVal", statusVal); //<= Now this string variable contains comma separated list box items values.
If you populate your list box on Page_Load then make sure that you should populate it into !Page.IsPostBack like
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
//Populate your list box here
}
}
And your SP is
CREATE DEFINER=`root`#`localhost` PROCEDURE `GetTMData1`(in statusVal varchar(255))
BEGIN
IF statusVal = '\'\'' THEN
select * from approved;
ELSE
SET #sql = CONCAT('SELECT * FROM approved WHERE status IN (', statusVal, ')');
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END IF ;
END
If you select multiple items from the dropdown then your SP's parameter data look like '\'apple\',\'banana\''. If not then it look like '\''.

There's a few issues that I could spot that may need to be addressed,
Ensure that the method BindDropDownList is only called on a non postback (page refresh), because your method PopulateDropDown is clearing the items on the list which means that viewstate cannot be restored in a postback, hence the probable reason why only one item is being selected.
I'm not 100% of the table schema, but the SQL provided does not seem to be able to query by more than one status properly, you should probably send a comma separated list of values, and in SQL turn them into a temp table so that you effectively search for items with multiple status (you should probably create a new question for this).
Do not use SelectedItem for multiple selections, instead you need to iterate your list items for those that are selected, and you don't need to use ViewState to pass it along (you probably did because of point 1. above). For example you could replace your method BindGrid and DropDownChange with:
private void BindGrid()
{
DataTable dt = new DataTable();
String strConnString = System.Configuration.ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
MySqlConnection con = new MySqlConnection(strConnString);
MySqlDataAdapter sda = new MySqlDataAdapter();
MySqlCommand cmd = new MySqlCommand("GetTMData");
cmd.CommandType = CommandType.StoredProcedure;
string statusVal = null;
foreach (ListItem item in ddlstatus.Items)
{
if(item.Selected)
{
if(statusVal.length > 0)
statusVal += ",";
statusVal += item.Value;
}
}
cmd.Parameters.AddWithValue("statusVal", statusVal);
cmd.Connection = con;
sda.SelectCommand = cmd;
sda.Fill(dt);
gdvTM.DataSource = dt;
gdvTM.DataBind();
}
protected void DropDownChange(object sender, EventArgs e)
{
this.BindGrid();
}

How to highlight search results in gridview using asp.net?

I am using a search box to sort my gridview according to the search text. I want to highlight the matching text in the gridview entered into the textbox.
This is my aspx page-
<table>
<tr>
<td>
<asp:TextBox ID="TextBox1" runat="server" Width="167px">
</asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:Button ID="Button1" runat="server" onclick="Button1_Click"
Text="Submit" Width="116px" />
</td>
</tr>
<tr>
<asp:GridView ID="GridView1" runat="server">
</asp:GridView>
</tr>
</table>
code behind
public void bind()
{
dt = g1.return_dt("select * from tbl1 where id is not null "
+ Session["Name"] + " order by compname ");
if (dt.Rows.Count > 0)
{
adsource = new PagedDataSource();
adsource.DataSource = dt.DefaultView;
adsource.PageSize = 10;
adsource.AllowPaging = true;
adsource.CurrentPageIndex = pos;
btnfirst.Enabled = !adsource.IsFirstPage;
btnprevious.Enabled = !adsource.IsFirstPage;
btnlast.Enabled = !adsource.IsLastPage;
btnnext.Enabled = !adsource.IsLastPage;
GridView1.DataSource = adsource;
GridView1.DataBind();
}
else
{
GridView1.DataSource = null;
GridView1.DataBind();
}
}
protected void Button1_Click(object sender, EventArgs e)
{
if (TextBox1.Text != "")
{
Session["Name"] = string.Format("and compname like '%{0}%' or productcategory like '%{0}%' or country like '%{0}%'");
}
else
{
Session["Name"] = null;
}
}
Please guide me how can I do this.

You can do it in two ways:
Modify the text in the relevant columns of you data table. (Find the text in each column and add an span with css class surrounding that text.) Here is a sample:
foreach(DataRow dr in dt.Rows)
{
foreach(DataColumn dc in dt.Columns)
{
string s = Convert.ToString(dr[dc.ColumnName]);
s = s.Replace("Your Search Text","<span style='color:RED'>Your Search Text</span>");
dr[dc.ColumnName] = s;
}
}
You can use javascript for the same and let the browser do all the hardwork. (Refer this link for a sample.)
Hope this helps.

Toggle display the child DataList

I am try to toggle the display subnet data(childList). This codes below are working fine, but not able to toogle the display. When I click on the (+) sign, the ChildList dataList expands and displays the list subset data (Contact). However, I want to change the (+) to (-) when childList data expanded. And when user clicks on (-), it will collapse back (the child list disappear)
Any idea how to do this? an example code would be great since I am a newbie of ASP.NET.
<table width="595px">
<asp:DataList BackColor="#ffffff" id="DataList1" DataSourceID="dsCompanyList" runat="server" Width="100%" DataKeyField="Company">
<ItemTemplate>
<tr>
<td>
<asp:LinkButton ID="LinkButton1" runat="server" Text="+" CommandArgument='<%#Container.ItemIndex%>'
OnCommand="LinkButton1_Command"
></asp:LinkButton>
</td>
<td><%#Eval("Row")%></td>
<td><%#Eval("Company")%></td>
</tr>
<asp:Panel ID="pnlChildView" runat="server">
<asp:DataList ID="childList" runat="server" Width="100%">
<ItemTemplate>
<tr>
<td><%#Eval("FirstName")%></td>
<td><%#Eval("LastName")%></td>
</tr>
</ItemTemplate>
</asp:DataList>
</asp:Panel>
</ItemTemplate>
</asp:DataList>
</table>
Code Behind:
public partial class _CompanyList2 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void LinkButton1_Command(object sender, CommandEventArgs e)
{
//pass index of item in command argument
int itemIndex = Convert.ToInt32(e.CommandArgument);
//depending on your needs bind the details on demand
//or preload during ItemDataBound
Panel childViewPanel = (Panel)DataList1.Items[itemIndex].FindControl("pnlChildView");
if (childViewPanel != null)
{
//toggle visibility of childViewPanel and bind child list if panel is visible
DataList childList = (DataList)childViewPanel.FindControl("childList");
if (childList != null)
{
//int keyValue = (int)DataList1.DataKeys[itemIndex];
string keyValue = (string)DataList1.DataKeys[itemIndex];
using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["connApps"].ConnectionString))
{
con.Open();
using (SqlCommand cmd = new SqlCommand("SELECT FirstName, LastName FROM dbo.Import_CompanyContact WHERE REPLACE(Company, '''', '') = '" + keyValue + "'", con))
{
cmd.CommandType = CommandType.Text;
using (SqlDataReader dr = cmd.ExecuteReader())
{
childList.DataSource = dr;
childList.DataBind();
}
}
}
}
}
}
}

Selected value on a DropDownList inside of a repeater

I'm adding a dropdwonlist inside of my repeater. Now I need to set a selected value for my dropdownlist.. but I'm not being very successful..
private void PhysicianSource()
{
DataSet ds = new DataSet();
DataTable dt = ds.Tables.Add("Source");
dt.Columns.Add("ID", Type.GetType("System.String"));
dt.Columns.Add("Desc", Type.GetType("System.String"));
Provider oProvider = new Provider();
List<ProviderLabel> lstprovider = oProvider.RetrievePhysicianList();
foreach (ProviderLabel item in lstprovider)
{
DataRow dr = dt.NewRow();
dr[0] = item.ProviderCode.ID.ToString();
dr[1] = item.Name.ToString();
dt.Rows.Add(dr);
}
drpPhysicianCode.DataSource = ds;
drpPhysicianCode.DataMember = "Source";
drpPhysicianCode.DataTextField = "ID";
drpPhysicianCode.DataValueField = "ID";
drpPhysicianCode.DataBind();
}
asp.net
<asp:Repeater ID="rptrPatientList" runat="server" >
<HeaderTemplate></HeaderTemplate>
<ItemTemplate>
<tr>
<td class="style2">
<asp:DropDownList ID="DropDownList1"
DataTextField="ID" runat="server"
DataValueField="Desc"
SelectedValue='<%# Eval("Code") %>'
DataSource="ds">
</asp:DropDownList>
</td>
</td>
</tr>
nothing happens on my codes.. help me guys I'm just a beginner on this.. thank you very much..

Hi Ian Ace its better to modify your code a little bit
<asp:Repeater ID="rptProductList" runat="server" OnItemDataBound="rptProductList_ItemDataBound">
<ItemTemplate>
<asp:DropDownList runat="server" ID="MyRepeater" AutoPostBack="true" OnSelectedIndexChanged="DropDownList_SelectedIndexChanged" >
</asp:DropDownList>
</ItemTemplate>
</asp:Repeater>
Now the code behind should be
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
fillRepeater();
}
}
}
protected void rptProductList_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
DropDownList MyDropDown= (DropDownList)e.Item.FindControl("MyRepeater");
if (MyDropDown!= null)
{
MyDropDown.DataSource = fillDropDown(MyDropDown);
MyDropDown.DataBind();
}
}
}
private DataSet fillDropDown(DropDownList dropDown)
{
// get your collection and return.
}
protected void DropDownList_SelectedIndexChanged(object sender, EventArgs e)
{
DropDownList MyDropDown= (DropDownList)sender;
string item = MyDropDown.SelectedValue;
}
hope the above example helps.

Try setting the selected value after data binding
Don't set the list contents with every postback. Check for Page.IsPostBack(). Note that this only works if you have ViewState enabled.

//Declare Class Scoped DataSet and DataTable variables
DataSet ds;
DataTable dt;
//Bind repeater and DataSource method
private void PhysicianSource()
{
ds = new DataSet();
dt = ds.Tables.Add("Source");
dt.Columns.Add("ID", Type.GetType("System.String"));
dt.Columns.Add("Desc", Type.GetType("System.String"));
Provider oProvider = new Provider();
List<ProviderLabel> lstprovider = oProvider.RetrievePhysicianList();
foreach (ProviderLabel item in lstprovider)
{
DataRow dr = dt.NewRow();
dr[0] = item.ProviderCode.ID.ToString();
dr[1] = item.Name.ToString();
dt.Rows.Add(dr);
}
drpPhysicianCode.DataSource = ds;
drpPhysicianCode.DataMember = "Source";
drpPhysicianCode.DataTextField = "ID";
drpPhysicianCode.DataValueField = "ID";
drpPhysicianCode.DataBind();
}
//Repeater Item Data Bound event in which we would find Controls to be bound
//and set DataSource and SelectedValue
protected void rptrPatientList_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
DropDownList DropDownList1 = e.Item.FindControl("DropDownList1") as DropDownList;
if (DropDownList1 != null)
{
DropDownList1.DataSource = dt;
DropDownList1.DataBind();
DropDownList1.SelectedValue = // DataBinder Eval 'Code' //;
}
}
}
<asp:Repeater ID="rptrPatientList" runat="server" OnItemDataBound="rptrPatientList_ItemDataBound">
<HeaderTemplate></HeaderTemplate>
<ItemTemplate>
<tr>
<td class="style2">
<asp:DropDownList ID="DropDownList1"
DataTextField="ID" runat="server"
DataValueField="Desc"
SelectedValue='<%# Eval("Code") %>'
DataSource="ds">
</asp:DropDownList>
</td>
</td>
</tr>

The problem occurs because the binding of dropdown occurs after that of repeater control. You can use HTML5 custom attributes, to set your dropdown value into a custom attribute, and then setting it as selected value after the dropdown is databinded. I have binded the dropdown using asp:ObjectDataSource
ASPX
<asp:Repeater ID="rptrPatientList" runat="server" >
<HeaderTemplate></HeaderTemplate>
<ItemTemplate>
<tr>
<td class="style2">
<asp:DropDownList ID="DropDownList1"
DataTextField="ID" runat="server"
DataValueField="Desc"
SetValue='<%# Eval("Code") %>' datasourceid="dsCategory"
datatextfield="ID" datavaluefield="desc" DataMember = "Source" onprerender="DropDownDataBinding">
</asp:DropDownList>
<asp:ObjectDataSource ID="dsCategory" runat="server" SelectMethod="PhysicianSource" TypeName="WebApplication.WebForm1" />
</td>
</td>
</tr>
CodeBehind
protected void DropDownDataBinding(object sender, EventArgs e) //Method to set the selected value on Category dropdown inside repeater
{
DropDownList sel = (DropDownList)sender;
sel.Value = sel.Attributes["SetValue"];
ListItem li = new ListItem("<< Select >>", "");
sel.Items.Insert(0,li);
}
protected DataSet PhysicianSource()
{
DataSet ds = new DataSet();
DataTable dt = ds.Tables.Add("Source");
dt.Columns.Add("ID", Type.GetType("System.String"));
dt.Columns.Add("Desc", Type.GetType("System.String"));
Provider oProvider = new Provider();
List<ProviderLabel> lstprovider = oProvider.RetrievePhysicianList();
foreach (ProviderLabel item in lstprovider)
{
DataRow dr = dt.NewRow();
dr[0] = item.ProviderCode.ID.ToString();
dr[1] = item.Name.ToString();
dt.Rows.Add(dr);
}
return ds;
}