Within a web form I am dynamically creating a series of chekboxes that are added to an asp:panel.Where as the panel in reside into a update panel.I want to avoid postback on checkbox changed event fire.
my code snippet:
Aspx code:
<asp:UpdatePanel ID="UpdatePanel2" runat="server">
<ContentTemplate>
<asp:Panel ID="pnlCuisine" runat="server"></asp:Panel>
</ContentTemplate>
C# Code:
public static CheckBox[] chkbx = new CheckBox[15];
public static Label[] lblCuisine = new Label[15];
private void LoadCuisine(string searchStr)
{
.....
.....
.....
int i = 1;
foreach(var item in cuisineList)
{
chkbx[i]=new CheckBox();
chkbx[i].ID = item.CategoryName;
chkbx[i].Text = item.CategoryName;
chkbx[i].AutoPostBack = true;
lblCuisine[i] = new Label();
lblCuisine[i].ID = "lblCuisine" + Convert.ToString(i);
lblCuisine[i].Text = "(" + item.Count + ")";
chkbx[i].CheckedChanged += new EventHandler(chkbx_CheckedChanged);
pnlCuisine.Controls.Add(chkbx[i]);
pnlCuisine.Controls.Add(lblCuisine[i]);
pnlCuisine.Controls.Add(new LiteralControl("<br/>"));
i++;
}
}
void chkbx_CheckedChanged(object sender, EventArgs e)
{
string searchString = ((CheckBox)sender).ClientID;
populateGrid(searchString);
}
Please change this line of code
chkbx[i].AutoPostBack = true;
to
chkbx[i].AutoPostBack = false;
then you can avoid auto post back on checkbox changed event fire
Related
I am trying to code a survey application which requires text boxes to be added and removed dynamically. I managed to create text boxes dynamically on button click but I'm trying to find out how to removed the text boxes dynamically. Currently the delete functions works well only if I remove text boxes starting from the last. When I try deleting any text boxes in the middle followed by a delete of the last text box, a blank text box is created instead. I'm new to programming and am unsure if this is the best method to use. Also, I would like to find out if it is possible to nest text boxes(allow users to add options to their multi choice questions) to created text boxes and retrieve values inside later.
Code behind:
public partial class Dynamic_Form : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
for (int i = 0; i < TotalNumberAdded; ++i)
{
AddQuestion(i + 1);
}
}
protected int TotalNumberAdded
{
get { return (int)(ViewState["TotalNumberAdded"] ?? 0); }
set { ViewState["TotalNumberAdded"] = value; }
}
protected void btn_add_Click(object sender, EventArgs e)
{
TotalNumberAdded++;
AddQuestion(TotalNumberAdded);
}
private void AddQuestion(int controlNumber)
{
Panel newquestion = new Panel();
newquestion.ID = "Panel_" + controlNumber;
TextBox questionbox = new TextBox();
questionbox.ID = "Question_" + controlNumber;
questionbox.Text = "Question";
Button BtnDelete = new Button();
BtnDelete.ID = "BtnDelete_" + controlNumber;
BtnDelete.Text = "Delete"+ controlNumber;
BtnDelete.Click += delete_Click;
DropDownList DDLType = new DropDownList();
DDLType.ID = "DDLType_" + controlNumber;
DDLType.Items.Insert(0, new ListItem("TextField", ""));
DDLType.Items.Insert(1, new ListItem("Multiple Choice", ""));
//add controls
questions.Controls.Add(newquestion);
newquestion.Controls.Add(questionbox);
newquestion.Controls.Add(DDLType);
newquestion.Controls.Add(BtnDelete);
}
private void delete_Click(object sender,EventArgs e)
{
Button btn = (Button)sender;
Control control = btn.Parent;
if (questions.Controls.Contains(control))
{
questions.Controls.Remove(control);
control.Dispose();
TotalNumberAdded--;
Response.Write("Number of Questions:" + TotalNumberAdded);
}
}
}
Html file:
<body>
<form id="form1" runat="server">
<div>
<h1>Test Form</h1>
<asp:Button ID="btn_add" runat="server" Text="Add" OnClick="btn_add_Click" />
</div>
<div id="questions" runat="server">
</div>
</form></body>
.
#Aaron Yong, You can do these scenarios from client side using jQuery or javascript too. I have given below code to achieve what you want from server side.
private void delete_Click(object sender,EventArgs e)
{
Button btn = (Button)sender;
Control control = btn.Parent;
if (questions.Controls.Contains(control))
{
TotalNumberAdded--;
questions.Controls.Clear();
for (int i = 0; i < TotalNumberAdded; ++i)
{
AddQuestion(i + 1);
}
Response.Write("Number of Questions:" + TotalNumberAdded);
}
}
You want to recreate controls again, i have added for loop and removed some code in delete click event, then you will achieve.
As i have given above answer, you can also remove below code from previous answered.
questions.Controls.Remove(control);
control.Dispose();
You will get exact answer
I am a noob and i've been trying to figure out how we may assign an ID to asp:TextBox tags on creation in ASP.NET using c#.
Example:
I need to create a thread that may have multiple textboxes.
When a user clicks on a button, a text box must be generated with an ID say, txt01. On being clicked the second time, the ID of the generated text box must be txt02 and so on..depending on the number of clicks.
Thanks in Advance.
Remember last ID in some variable, for example int lastID, then in button's onClick method when creating the new TextBox assign its ID="txt"+lastID;.
You have to persist the lastID during page postbacks, you can store it in a ViewState.
Take and placeholder in your aspx page: eg: <asp:PlaceHolder runat="server" ID="pholder" />
and in code behind:
TextBox txtMyText = new TextBox();
tb1.ID = YourDynamicId;
pholder.Controls.Add(txtMyText);
You can save current id in ViewState and get the same id and assign incremented id to your dynamic textbox.
Try This:
int i = 1;
if (ViewState["i"] == null)
{
ViewState["i"] = i;
}
else
i = (int)ViewState["i"];
PlaceHolder1.Controls.Clear();
for (int j = 1; j <= i; j++)
{
TextBox TextBox = new TextBox();
TextBox.ID = "TextBox" + j.ToString();
PlaceHolder1.Controls.Add(TextBox);
}
ViewState["i"] = i + 1;
add this on your .aspx page
<asp:PlaceHolder ID="PlaceHolder1" runat="server"></asp:PlaceHolder>
Hope This help.
I think this is what you are looking for -
You will notice that I have used Page_Init because if you create/add the controls in Page_Load then FindControl will return null in PostBack. And also any data you entered in the dynamically added controls will not persist during Postbacks.
But Page_Init is called before ViewState or PostBack data is loaded. Therefore, you can not use ViewState or any other controls to keep the control count. So I have used Session to keep the count.
Try it out and let me know what you think.
ASPX Page
<form id="form1" runat="server">
<asp:PlaceHolder ID="PlaceHolder1" runat="server"></asp:PlaceHolder>
<asp:Button ID="btnCreate" runat="server" Text="Create" OnClick="btnCreate_Click" />
<asp:Button ID="btnRead" runat="server" Text="Read" OnClick="btnRead_Click" />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</form>
Code Behind
protected int NumberOfControls
{
get { return Convert.ToInt32(Session["noCon"]); }
set { Session["noCon"] = value.ToString(); }
}
private void Page_Init(object sender, System.EventArgs e)
{
if (!Page.IsPostBack)
//Initiate the counter of dynamically added controls
this.NumberOfControls = 0;
else
//Controls must be repeatedly be created on postback
this.createControls();
}
private void Page_Load(object sender, System.EventArgs e)
{
}
protected void btnCreate_Click(object sender, EventArgs e)
{
TextBox tbx = new TextBox();
tbx.ID = "txtData"+NumberOfControls;
NumberOfControls++;
PlaceHolder1.Controls.Add(tbx);
}
protected void btnRead_Click(object sender, EventArgs e)
{
int count = this.NumberOfControls;
for (int i = 0; i < count; i++)
{
TextBox tx = (TextBox)PlaceHolder1.FindControl("txtData" + i.ToString());
//Add the Controls to the container of your choice
Label1.Text += tx.Text + ",";
}
}
private void createControls()
{
int count = this.NumberOfControls;
for (int i = 0; i < count; i++)
{
TextBox tx = new TextBox();
tx.ID = "txtData" + i.ToString();
//Add the Controls to the container of your choice
PlaceHolder1.Controls.Add(tx);
}
}
store the id in a ViewState something like this
First initialise a count variable similiar to this.
in your class write this
protected int replyCount //declare the variable
{
get { return (int)ViewState["replyCount"]; }
set { ViewState["replyCount"] = value; }
}
In your page Load write this to initialise the replyCount if its not a postback;
protected void Page_Load(object sender, EventArgs e)
{
if(!page.IsPostBack)
{
replyCount = 0; //initialise the variable
}
}
then while creating dynamic textboxes
protected void Button_Click(Object sender, EventArgs e)
{
TextBox tb = new TextBox();
tb.id = "tb" + replycount; //use the variable
replycount++; // and after using increment it.
form.controls.add(tb); // assuming your form name is "form"
}
Thats it you should do.
I have a problem with my dynamic updatepanel that I've created.
The problem is that i want to add a validator,i.e RequriedFieldValidator, to every element that i'm creating on the serverside.
This above works fine.
But when i'm clicking the submit button it does nothing. I can see in the htmlShellcode that a span element is there showing the error, but it has the "style="visibility=hidden".
How do i solve this issue? i'm not really sure i'm doing it right from the beginning either(very new to programming).
MARKUP:
<asp:Panel ID="UpdatepanelWrapper" CssClass="Updatepanelwrapper" runat="server">
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:PlaceHolder runat="server" ID="WholeWrapper">
<asp:PlaceHolder runat="server" ID="QuestionWrapper">
<asp:PlaceHolder runat="server" ID="LabelQuestion"><asp:PlaceHolder>
<asp:PlaceHolder runat="server" ID="Question"></asp:PlaceHolder>
</asp:PlaceHolder>
</asp:PlaceHolder>
</asp:PlaceHolder>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnAdd" EventName="Click" />
<asp:AsyncPostBackTrigger ControlID="btnDelete" EventName="Click" />
</Triggers>
</asp:UpdatePanel>
<asp:Panel ID="ButtonPanel" CssClass="ButtonPanel" runat="server">
<asp:ImageButton ID="btnDelete" runat="server" ImageUrl="~/Images/Deleteicon.png" CssClass="DeleteButton" OnClientClick="btnDelete_Click" />
<asp:ImageButton ID="btnAdd" runat="server" ImageUrl="~/Images/Addicon.png" CssClass="AddButton" OnClientClick="btnAddQuestion_Click" />
</asp:Panel>
</asp:Panel>
SERVERSIDE CODE: (Override method OnInit is the important one)
public partial class _Default : Page
{
static int CountOfQuestions = 1;
private RequiredFieldValidator[] ArrRequiredFieldQuestion;
private Panel[] ArrWholePanel;
private Panel[] ArrQuestionPanel;
private Label[] ArrQuestionLabel;
private TextBox[] ArrQuestionBox;
protected void Page_Load(object sender, EventArgs e)
{
}
private void LoadControls()
{
Control myControl = GetPostBackControl(this.Page);
if (myControl != null)
{
if (myControl.ID.ToString() == "btnAdd") //Ändra till btnAddQuestion om en "button" ska användas
{
CountOfQuestions++;
}
if (myControl.ID.ToString() == "btnDelete")
{
CountOfQuestions--;
}
}
}
protected override void OnInit(EventArgs e)
{
base.OnInit(e);
if (!IsPostBack)
{
CountOfQuestions = 1;
}
LoadControls();
ArrRequiredFieldQuestion = new RequiredFieldValidator[CountOfQuestions];
ArrWholePanel = new Panel[CountOfQuestions];
ArrQuestionPanel = new Panel[CountOfQuestions];
ArrQuestionLabel = new Label[CountOfQuestions];
ArrQuestionBox = new TextBox[CountOfQuestions];
for (int i = 0; i < CountOfQuestions; i++)
{
RequiredFieldValidator ReqFieldQuestion = new RequiredFieldValidator();
PlaceHolder WholeWrapper = UpdatePanel1.FindControl("WholeWrapper") as PlaceHolder;
Panel WholePanel = new Panel();
Panel QuestionPanel = new Panel();
Panel CorrectAnswerPanel = new Panel();
Label QuestionLabel = new Label();
TextBox Question = new TextBox();
QuestionLabel.Text = "Write your question";
Question.TextMode = TextBoxMode.MultiLine;
Question.Width = 550;
Question.Height = 50;
WholePanel.ID = "WholePanel" + i.ToString();
QuestionPanel.ID = "QuestionPanel" + i.ToString();
Question.ID = "tbxQuestion" + i.ToString();
ReqFieldQuestion.ID = "Validate" + i.ToString();
ReqFieldQuestion.ControlToValidate = "tbxQuestion" + i.ToString();
ReqFieldQuestion.ValidationGroup = "QuestionGroup";
ReqFieldQuestion.ErrorMessage = "Error";
ReqFieldQuestion.Attributes.Add("runat", "server");
QuestionPanel.CssClass = "QuestionEntry";
QuestionPanel.Controls.Add(QuestionLabel);
QuestionPanel.Controls.Add(Question);
QuestionPanel.Controls.Add(ReqFieldQuestion);
WholeWrapper.Controls.Add(WholePanel);
WholePanel.Controls.Add(QuestionPanel);
ArrRequiredFieldQuestion[i] = ReqFieldQuestion;
ArrQuestionPanel[i] = QuestionPanel;
ArrQuestionLabel[i] = QuestionLabel;
ArrQuestionBox[i] = Question;
}
}
protected void btnAddQuestion_Click(object sender, EventArgs e)
{
//Handeld by Pre_init and LoadControls
}
protected void btnDelete_Click(object sender, EventArgs e)
{
//Handeld by Pre_init and LoadControls
}
public static Control GetPostBackControl(Page thePage)
{
Control postbackControlInstance = null;
if (postbackControlInstance == null)
{
for (int i = 0; i < thePage.Request.Form.Count; i++)
{
if ((thePage.Request.Form.Keys[i].EndsWith(".x")) || (thePage.Request.Form.Keys[i].EndsWith(".y")))
{
postbackControlInstance = thePage.FindControl(thePage.Request.Form.Keys[i].Substring(0, thePage.Request.Form.Keys[i].Length - 2));
return postbackControlInstance;
}
}
}
return postbackControlInstance;
}
But when i'm clicking the submit button it does nothing.
Since I don't see a Submit button, I'm taking a guess that you mean the Add and Remove buttons. If this is the case, the problem is that all your RequiredFieldValidators have the ValidationGroup property set to QuestionGroup but this is not set in any of your buttons.
Modify the Buttons like this:
<asp:ImageButton ID="btnAdd" runat="server" ValidationGroup="QuestionGroup" ... />
Here is code. Its not showing any compile or run time error. I debugged also then till data binding works fine. But then also controls not shown in web page!
Sample.aspx:
<body>
<form id="form1" runat="server">
<asp:PlaceHolder ID="_placeHolder1" runat="server">
</asp:PlaceHolder>
</form>
</body>
Sample.aspx.cs:
protected void Page_Load(object sender, EventArgs e)
{
_placeHolder1.Controls.Add(CreateReapeater());
}
private Control CreateReapeater()
{
Repeater _repeater1 = new Repeater();
Stack _stack1 = new Stack();
for (int i = 0; i < 7; i++)
{
_stack1.Push(i);
}
_repeater1.DataSource = _stack1;
_repeater1.DataBind();
return _repeater1;
}
Actually repeater have no inbuild column structure as like gridview. so when we bind repeater dynamically we need to also create the item template for that.
You need to modify the createrepeater function as below.
private Control CreateReapeater()
{
Repeater _repeater1 = new Repeater();
Stack _stack1 = new Stack();
for (int i = 0; i < 7; i++)
{
_stack1.Push(i);
}
_repeater1.DataSource = _stack1;
_repeater1.DataBind();
foreach (RepeaterItem repeatItem in _repeater1.Items)
{
int index = repeatItem.ItemIndex;
RepeaterItem repeaterItem = new RepeaterItem(repeatItem.ItemIndex, ListItemType.Item);
Label lbl = new Label();
lbl.Text = "Item No :" + index.ToString() + "<br/>";
repeatItem.Controls.Add(lbl);
}
return _repeater1;
}
This will resolve your issue.
Happy Coding.....
I'm using PostBackUrl to post my control from a "firstwebpage.aspx" to a "secondwebpage.aspx" so that I would be able to generate some configuration files.
I do understand that I can make use of PreviousPage.FindControl("myControlId") method in my secondwebpage.aspx to get my control from "firstwebpage.aspx"and hence grab my data and it worked.
However, it seems that this method does not work on controls which I generated programmically during runtime while populating them in a table in my firstwebpage.aspx.
I also tried using this function Response.Write("--" + Request["TextBox1"].ToString() + "--");
And although this statement do printout the text in the textfield on TextBox1, it only return me the string value of textbox1. I am unable to cast it to a textbox control in the following format too
TextBox temptextBox = (TextBox)Request["TextBox1"];
My question is, how can I actually access the control which i generated programmically in "firstwebpage.aspx" on "secondwebpage.aspx"?
Please advice!
thanks alot!
//my panel and button in aspx
<asp:Panel ID="Panel2" runat="server"></asp:Panel>
<asp:Button ID="Button1" runat="server" Text="Generate Xml" PostBackUrl="~/WebForm2.aspx" onclick="Button1_Click" />
//this is my function to insert a line into the panel
public void createfilerow(string b, string path, bool x86check, bool x86enable, bool x64check, bool x64enable)
{
Label blank4 = new Label();
blank4.ID = "blank4";
blank4.Text = "";
Panel2.Controls.Add(blank4);
CheckBox c = new CheckBox();
c.Text = b.Replace(path, "");
c.Checked = true;
c.ID = "1a";
Panel2.Controls.Add(c);
CheckBox d = new CheckBox();
d.Checked = x86check;
d.Enabled = x86enable;
d.ID = "1b";
Panel2.Controls.Add(d);
CheckBox e = new CheckBox();
e.Checked = x64check;
e.Enabled = x64enable;
e.ID = "1c";
Panel2.Controls.Add(e);
}
//my virtual path in WebForm2.aspx
<%# PreviousPageType VirtualPath="~/WebForm1.aspx" %>
//my pageload handler
protected void Page_Load(object sender, EventArgs e)
{
if (PreviousPage != null)
{
CheckBox tempCheckbox = (CheckBox)Page.PreviousPage.FindControl("1a");
Button1.Text = tempCheckbox.Text;
}
}
//handler which will populate the panel upon clicking
protected void Button7_Click(object sender, EventArgs e)
{
//get foldername
if (!Directory.Exists(#"myfilepath" + TextBox2.Text))
{
//folder does not exist
//do required actions
return;
}
string[] x86files = null;
string[] x64files = null;
string[] x86filespath = null;
string[] x64filespath = null;
ArrayList common = new ArrayList();
if (Directory.Exists(#"myfilepath" + TextBox2.Text + "\\x86"))
x86files = Directory.GetFileSystemEntries("myfilepath" + TextBox2.Text + "\\x86");
if (Directory.Exists(#"myfilepath" + TextBox2.Text + "\\x64"))
x64files = Directory.GetFileSystemEntries("myfilepath" + TextBox2.Text + "\\x64");
//some codes to convert x64files and x86files to string[]
//The header for Panel, 4 column
Label FL = new Label();
FL.ID = "flavourid";
FL.Text = "Flavour";
Panel2.Controls.Add(FL);
Label filetext = new Label();
filetext.ID = "filenamelabel";
filetext.Text = "File(s)";
Panel2.Controls.Add(filetext);
Label label86 = new Label();
label86.ID = "label86";
label86.Text = "x86";
Panel2.Controls.Add(label86);
Label label64 = new Label();
label64.ID = "label64";
label64.Text = "x64";
Panel2.Controls.Add(label64);
//a for loop determine number of times codes have to be run
for (int a = 0; a < num; a++)
{
ArrayList location = new ArrayList();
if (//this iteration had to be run)
{
string path = null;
switch (//id of this iteration)
{
case id:
path = some network address
}
//check the current version of iternation
string version = //version type;
//get the platform of the version
string platform = //platform
if (curent version = certain type)
{
//do what is required.
//build a list
}
else
{
//normal routine
//do what is required
//build a list
}
//populating the panel with data from list
createflavourheader(a);
//create dynamic checkboxes according to the list
foreach(string s in list)
//createrow parameter is by version type and platform
createfilerow(readin, path, true, true, false, false);
}
}
}
form1.Controls.Add(Panel2);
}
Sorry can't show you the full code as it is long and I believe it should be confidential even though i wrote them all
Yes you can access, Below is an example
// On Page1.aspx I have a button for postback
<asp:Button ID="btnSubmit" runat="server" Text="Submit"
PostBackUrl="~/Page2.aspx" />
// Page1.aspx.cs
protected void Page_Load(object sender, EventArgs e)
{
TextBox t = new TextBox(); // created a TextBox
t.ID = "myTextBox"; // assigned an ID
form1.Controls.Add(t); // Add to form
}
Now on the second page I will get the value of TextBox as
// Page2.aspx.cs
protected void Page_Load(object sender, EventArgs e)
{
if (PreviousPage != null)
{
TextBox t = (TextBox) PreviousPage.FindControl("myTextBox");
string mytboxvalue = t.Text;
}
// OR
string myTextBoxValue = Request.Form["myTextBox"];
}
Updated Answer:
Panel myPanel = new Panel();
myPanel.ID = "myPanel";
TextBox t = new TextBox();
t.ID = "myTextBox";
myPanel.Controls.Add(t);
TextBox t1 = new TextBox();
t1.ID = "myTextBox1";
myPanel.Controls.Add(t1);
// Add all your child controls to your panel and at the end add your panel to your form
form1.Controls.Add(myPanel);
// on the processing page you can get the values as
protected void Page_Load(object sender, EventArgs e)
{
if (PreviousPage != null)
{
TextBox t = (TextBox) PreviousPage.FindControl("myTextBox");
string mytboxvalue = t.Text;
}
string myTextBoxValue = Request.Form["myTextBox1"];
}
I also tried using this function Response.Write("--" +
Request["TextBox1"].ToString() + "--"); And although this statement do
printout the text in the textfield on TextBox1, it only return me the
string value of textbox1. I am unable to cast it to a textbox control
in the following format too
TextBox temptextBox = (TextBox)Request["TextBox1"];
Hi lw,
I think you may try passing the type of control (e.g. 'tb') together with the content and creating a new object (e.g. TextBox) and assign it to templtexBox object.
My 20 cents.
Andy