I have masterpage & content page. In master Page I have DropDownList of Cities which Gets cities from database. And in my content page I DropDownList Of Areas which also comes from database. Now Suppose If My city gets changed then desire area related to that particular selected city should also get changed. I have manage my db tables properly & passing correct query as well. But DropDownList Of areas doesn't gets refreshed if City DropDownList gets changed. Following code I am trying.
MasterPage
Private Sub MasterPage_Load(sender As Object, e As EventArgs) Handles Me.Load
Me.PopulateCities()
If Not IsPostBack Then
If Session("masterLocation") Is Nothing Then
Session("cityName") = "Pune"
Else
locationSelector.Text = Session("masterLocation").ToString()
End If
End If
locationPopupActivator.Text = locationSelector.SelectedValue.ToString
End Sub
Private Sub PopulateCities()
Using conn As New MySqlConnection()
conn.ConnectionString = ConfigurationManager _
.ConnectionStrings("conio").ConnectionString()
Using cmd As New MySqlCommand()
cmd.CommandText = "Select cityName from cities where status = 'active' order by cityName"
cmd.Connection = conn
conn.Open()
Using sdr As MySqlDataReader = cmd.ExecuteReader()
While sdr.Read()
Dim item As New ListItem()
item.Text = sdr("cityName").ToString()
item.Value = sdr("cityName").ToString()
'item.Selected = Convert.ToBoolean(sdr("IsSelected"))
locationSelector.Items.Add(item)
End While
End Using
conn.Close()
End Using
End Using
End Sub
ContentPage
Private Sub hospitals_PreRender(sender As Object, e As EventArgs) Handles Me.PreRender
If Not IsPostBack Then
Me.PopulateAreas()
End If
End Sub
Private Sub PopulateAreas()
areasList.Items.Clear()
Dim citySelector As RadioButtonList = Page.Master.FindControl("locationSelector")
Using conn As New MySqlConnection()
conn.ConnectionString = ConfigurationManager _
.ConnectionStrings("conio").ConnectionString()
Using cmd As New MySqlCommand()
cmd.CommandText = "Select * from areas where areaCity like '" + citySelector.SelectedItem.ToString + "%'"
cmd.Connection = conn
conn.Open()
Using sdr As MySqlDataReader = cmd.ExecuteReader()
While sdr.Read()
Dim item As New ListItem()
item.Text = sdr("areaName").ToString()
item.Value = sdr("areaName").ToString()
'item.Selected = Convert.ToBoolean(sdr("IsSelected"))
areasList.Items.Add(item)
End While
End Using
conn.Close()
End Using
End Using
areasList.Items.Insert(0, New ListItem("All Area", "All"))
End Sub
Everything in your code is fine just make changes On Pre_Render event of your content page
If IsPostBack Then
Me.PopulateAreas()
End If
Make this changes. Hope this will solve your problem.
Related
I'm facing very un natural problem suddenly. I have DropDownList with autopostback is true. Postback executes a method which populates other things onpage according to selection. Now When I select any value first time from that dropdown then page gets postback but nothing get populate but from second time it works fine. Even I put breakpoint on that dropdown & it's not even hitting breakpoint for first postback.
<asp:DropDownList ID="ClientCode" runat="server" ClientIDMode="Static" CssClass="field-pitch" AutoPostBack="true"></asp:DropDownList>
Private Sub ClientCode_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ClientCode.SelectedIndexChanged
Me.populateConsignerDetails()
End Sub
Private Sub populateConsignerDetails()
Try
Dim str As String = "SELECT * FROM clientsDetails WHERE clientID = #clientID"
con.Open()
Dim cmd As New MySqlCommand(str, con)
cmd.Parameters.AddWithValue("#clientID", ClientCode.SelectedItem.ToString)
Dim da As New MySqlDataAdapter(cmd)
Dim dt As New DataTable
da.Fill(dt)
con.Close()
Dim payingParty As String = String.Empty
If dt.Rows.Count > 0 Then
consignerName.Text = dt.Rows(0)("clientName").ToString
consignerAddress.Text = dt.Rows(0)("companyAddress").ToString
consignerMobile1.Text = dt.Rows(0)("contactNumber1").ToString
consignerCity.Text = dt.Rows(0)("city").ToString
consignerState.Text = dt.Rows(0)("state").ToString
consignerPinCode.Text = dt.Rows(0)("pinCode").ToString
End If
Catch ex As Exception
Response.Write(ex)
End Try
End Sub
Update
Private Sub myadmin_shipment_details2_Load(sender As Object, e As EventArgs) Handles Me.Load
If Not Me.IsPostBack Then
populateClient()
End If
End Sub
Private Sub populateClient()
Using conn As New MySqlConnection()
conn.ConnectionString = ConfigurationManager _
.ConnectionStrings("conio").ConnectionString()
Using cmd As New MySqlCommand()
cmd.CommandText = "Select * from clientsDetails where status = 'active'"
cmd.Connection = conn
conn.Open()
Using sdr As MySqlDataReader = cmd.ExecuteReader()
While sdr.Read()
Dim item As New ListItem()
item.Text = sdr("clientID").ToString()
item.Value = sdr("ClientName").ToString()
ClientCode.Items.Add(item)
End While
End Using
conn.Close()
End Using
End Using
End Sub
I want to get the sum of the selected items in the listbox and display them in a label but i am always getting 0,i also want to put the selected items in another label too which is also not working.
Here is what the code look like:
Dim sum As Integer
Dim Items1 As String = "None"
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
Label2.Text = Request.QueryString("Name").ToString()
Dim connetionString As String = Nothing
Dim connection As SqlConnection
Dim command As SqlCommand
Dim adapter As New SqlDataAdapter()
Dim ds As New DataSet()
Dim sql As String
connetionString = "Data Source=.;Initial Catalog=Shop;integrated security=true"
sql = "select PhoneName,PhonePrice from SmartPhones"
connection = New SqlConnection(connetionString)
connection.Open()
command = New SqlCommand(sql, connection)
adapter.SelectCommand = command
adapter.Fill(ds)
adapter.Dispose()
command.Dispose()
connection.Close()
ListBox1.DataSource = ds.Tables(0)
ListBox1.DataTextField = "PhoneName"
ListBox1.DataValueField = "PhonePrice"
ListBox1.DataBind()
End Sub
code where the display should happen:
Protected Sub Button2_Click(sender As Object, e As EventArgs) Handles TotalPrice.Click
sum = 0 'reset sum to 0
For Each i As Integer In ListBox1.GetSelectedIndices
Dim CurrentItem As ListItem = ListBox1.Items(i)
sum = sum + CInt(CurrentItem.Value)
Items1 = Items1 + " , " + CStr(CurrentItem.Text)
Next
Label3.Text = Items1
Label1.Text = sum
End Sub
Here is the page Design and the Page On the web Respectively:
PhoneName is of type varchar in database & PhonePrice is of type integer (Both Filled correctly).
ListBox code:
<asp:ListBox ID="ListBox1" runat="server" SelectionMode="Multiple" ></asp:ListBox>
What's the reason that the code won't give me the desired result?
What is happening is that when you click TotalPrice a postback is performed (What is a postback?). If you look at the ASP.NET page lifecycle you will see that the Load event happens before the postback event handling (e.g. your Sub Button2_Click).
So, you click the button, it runs the Me.Load handler and... your list is reset before the click handler gets a chance to run.
There is a property you can check to see if the page is running as a result of a postback: Page.IsPostBack.
So all you need to do is check it to see if you need to populate the list:
Sub FillItemsList()
Dim connectionString As String = "Data Source=.;Initial Catalog=Shop;integrated security=true"
Dim dt As New DataTable()
Using connection As New SqlConnection(connectionString)
Dim sql As String = "SELECT PhoneName,PhonePrice FROM SmartPhones"
Using adapter As New SqlDataAdapter(sql, connection)
adapter.Fill(dt)
End Using
End Using
ListBox1.DataSource = dt
ListBox1.DataTextField = "PhoneName"
ListBox1.DataValueField = "PhonePrice"
ListBox1.DataBind()
End Sub
Private Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
Label2.Text = Request.QueryString("Name").ToString()
If Not Page.IsPostBack Then
FillItemsList()
End If
End Sub
I am trying to populate My RadioButtonList values from database. That is working for me. But I am not getting how should I keep one predefined values in database to be selected by default in radiobuttonList. I have list of cities in my db table. One city I want to be selected when page loads. Following is my code
Private Sub MasterPage_Load(sender As Object, e As EventArgs) Handles Me.Load
If Not IsPostBack Then
Me.PopulateCities()
End Sub
Private Sub PopulateCities()
Using conn As New MySqlConnection()
conn.ConnectionString = ConfigurationManager _
.ConnectionStrings("conio").ConnectionString()
Using cmd As New MySqlCommand()
cmd.CommandText = "Select cityName from cities where status = 'active' order by cityName"
cmd.Connection = conn
conn.Open()
Using sdr As MySqlDataReader = cmd.ExecuteReader()
While sdr.Read()
Dim item As New ListItem()
item.Text = sdr("cityName").ToString()
item.Value = sdr("cityName").ToString()
item.Selected = Convert.ToBoolean(sdr("IsSelected"))
locationSelector.Items.Add(item)
End While
End Using
conn.Close()
End Using
End Using
If you database cities table contains IsSelected field then you need to change your query like this
Select cityName, IsSelected from cities where status = 'active' order by cityName
Elese you need to update your first list item
locationSelector.Items(0).Selected = True
I have bind my dropdownlist with database. But on each PostBack the items in dropdownlist gets repeat again.
e.g.
OnPage Load I have this items in dropdownlist 1,2,3,4.. etc Now suppose page gets postBack then it looks like 1,2,3,4,1,2,3,4
Vb code
Private Sub hospitals_Load(sender As Object, e As EventArgs) Handles Me.Load
Me.PopulateAreas()
End Sub
Private Sub PopulateAreas()
If IsPostBack Then
Dim citySelector As DropDownList = Page.Master.FindControl("locationSelector")
Using conn As New MySqlConnection()
conn.ConnectionString = ConfigurationManager _
.ConnectionStrings("conio").ConnectionString()
Using cmd As New MySqlCommand()
cmd.CommandText = "Select * from areas where areaCity Like '" + citySelector.SelectedItem.ToString + "%'"
cmd.Connection = conn
conn.Open()
Using sdr As MySqlDataReader = cmd.ExecuteReader()
While sdr.Read()
Dim item As New ListItem()
item.Text = sdr("areaName").ToString()
item.Value = sdr("areaID").ToString()
'item.Selected = Convert.ToBoolean(sdr("IsSelected"))
areasList.Items.Add(item)
End While
End Using
conn.Close()
End Using
End Using
End If
UPDATE
I have master page which has dropdownlist of cities. I am using masterpage control to mycontent page like below.
Dim citySelector As DropDownList = Page.Master.FindControl("locationSelector")
Now in my PopulateArea() class there is query in which WHERE clause have cityselector. So according to city my area gets fetched.
Call your function inside not postback event so that the dropdown is not called on postback events(which fills it everything).
Private Sub hospitals_Load(sender As Object, e As EventArgs) Handles Me.Load
if ispostback = false then
Me.PopulateAreas()
end if
End Sub
its pretty simple.. the page load event is triggered every time anything is post back.
use this
Private Sub hospitals_Load(sender As Object, e As EventArgs) Handles Me.Load
If Page.IsPostBack Then
//do stuff when post back occurs
Else
Me.PopulateAreas() //put this function here so that it executes only once
End If
End Sub
If your dropdown values have to change on the postback. Say initially the values where 1,2,3,4 and on postback if the values has to be 2,3,4,5 based on some of the values you change on the form controls you will have to clear the dropdown values first and then add new values to it.
areasList.Items.Clear()
Also see that AppendDataBoundItems is not true: in your .aspx page
Change your code to,
Private Sub PopulateAreas()
If IsPostBack Then
areasList.Items.clear()
Dim citySelector As DropDownList = Page.Master.FindControl("locationSelector")
Using conn As New MySqlConnection()
conn.ConnectionString = ConfigurationManager _
.ConnectionStrings("conio").ConnectionString()
Using cmd As New MySqlCommand()
cmd.CommandText = "Select * from areas where areaCity Like '" + citySelector.SelectedItem.ToString + "%'"
cmd.Connection = conn
conn.Open()
Using sdr As MySqlDataReader = cmd.ExecuteReader()
While sdr.Read()
Dim item As New ListItem()
item.Text = sdr("areaName").ToString()
item.Value = sdr("areaID").ToString()
'item.Selected = Convert.ToBoolean(sdr("IsSelected"))
areasList.Items.Add(item)
End While
End Using
conn.Close()
End Using
End Using
End If
End Sub
I'm a beginner in vb.net. Currently I'm develop a simple application by using a grid view. however, I'm facing a problem in deleting the data. When I click delete button, it keep adding the blank line. and this blank line is affected my database also. and this blank line also can't be deleted from database manually.
here my code behind
`Imports System.Data.SqlClient
Imports System.Drawing
Imports System.Data
Imports System.Configuration
Imports System.Linq
Partial Class test2
Inherits System.Web.UI.Page
Dim AMS As String = System.Web.Configuration.WebConfigurationManager.ConnectionStrings("AMS").ConnectionString
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
If Not IsPostBack Then
Me.BindData()
End If
End Sub
Private Sub BindData()
Dim dt As DataTable = New DataTable
Dim strConnString As String = ConfigurationManager.ConnectionStrings("AMS").ConnectionString
Using con As SqlConnection = New SqlConnection(strConnString)
Dim strQuery As String = "SELECT * FROM ModuleDetail"
Using cmd As SqlCommand = New SqlCommand(strQuery)
Dim sda As SqlDataAdapter = New SqlDataAdapter
cmd.Connection = con
con.Open()
sda.SelectCommand = cmd
sda.Fill(dt)
GridView1.DataSource = dt
GridView1.DataBind()
End Using
End Using
End Sub
Protected Sub GridView1_RowDeleting(ByVal sender As Object, ByVal e As GridViewDeleteEventArgs)
Dim IsDeleted As Boolean = False
Dim ModuleID As String = Convert.ToInt32(GridView1.DataKeys(e.RowIndex).Value.ToString())
Dim ModuleName As Label = CType(GridView1.Rows(e.RowIndex).FindControl("lblModuleName"), Label)
Dim SubModule As Label = CType(GridView1.Rows(e.RowIndex).FindControl("lblSubModule"), Label)
Dim strConnString As String = ConfigurationManager.ConnectionStrings("AMS").ConnectionString
Using con As SqlConnection = New SqlConnection(strConnString)
Using cmd As SqlCommand = New SqlCommand
cmd.CommandType = CommandType.Text
cmd.CommandText = "DELETE FROM ModuleDetail WHERE ModuleID=#ModuleID"
cmd.Parameters.AddWithValue("#ModuleID", ModuleID)
cmd.Connection = con
con.Open()
IsDeleted = cmd.ExecuteNonQuery() > 0
con.Close()
GridView1.DataSource = cmd
GridView1.DataBind()
End Using
End Using
If IsDeleted Then
lblMsg.Text = "'" & SubModule.Text & "' details has been deleted successfully!"
lblMsg.ForeColor = System.Drawing.Color.Green
BindData()
Else
lblMsg.Text = "Error while deleting '" & SubModule.Text & "' details"
lblMsg.ForeColor = System.Drawing.Color.Red
End If
End Sub
`
I have try a few code from others sources but it shows the same logic error which keep adding the blank line. I hope you guys can help me to solve the issue.
Though it might not relevant to your problem context, but I have observed a couple of issues from your code:
1) It seems you are binding grid twice after row delete.
2) Try commenting following lines since you already calling BindData() whithin IsDeleted flag check.
GridView1.DataSource = cmd;
GridView1.DataBind();
3) You are assigning the 'Command' object: cmd to the Grid's datasource which is not correct. Check your BindData(...) method how you need to bind Grid actually.