I want to create dynamic text boxes during run time.
Suppose im gettng a text from a database as "# is the capital of India" now i want to replace that "#" by text box while it is rendered to user as below
<asp:TextBox runat="server" id = "someid"></asp:TextBox> is the capital of India
Im able to get the textbox and text as combination. However I cannot access the textboxes with the given id and when any event occurs on the page the textboxes are lost as they logically does not exist untill their state is stored.
I also went through the concepts of place holder and Viewstate to store the dynamically created controls and make their id's available for the methods, but as far as I tried I could not meet the textbox and text combination requirement.
Im looping over the entire text recieved from database and checking if there is any"#". Is yes then i want to replace it with a textbox on which i can call methods to take back the value entered in the text box to database and store it.
eg: text is "#" is the capital of India
for (int i = 0; i < que.Length; j++) //que holds the text
{
if (que[i] == '#')
{
//Textbox should be created
}
else
{
//the texts should be appended before or after the textbox/textboxes as text demands
}
}
On button click I'm passing request to database, which will send me necessary details i.e. question text, options and also saves the current checked value etc.
protected void BtnLast_Click(object sender, EventArgs e)
{
CheckBox1.Checked = false;
CheckBox2.Checked = false;
CheckBox3.Checked = false;
CheckBox4.Checked = false;
QuestionSet q = new QuestionSet();
StudentB b = new StudentB();
q = b.GetQuestion(1, 1, qid, 'L', 0, Checked, date);
qid = Convert.ToInt32(q.Question_Id);
Checked = q.Checked;
if (q.Question_Type == 11) //indicates its objective Question
{
//ill bind data to checkboxes
}
else if (q.Question_Type == 12) // indicate its fill in the blanks question
{
for (int j = 0; j < que.Length; j++)
{
if (que[j] == '#')
{
count++;
string res = "<input type = 'text' runat = 'server' id ='TxtBoxFillUp" + count + "'/>";
htm = htm.Append(res);
}
else
{
htm = htm.Append(que[j]);
}
}
}
}
Any help will be greatly appreciated, thanks in advance.
Adding control in the way you do it won't create control as asp.net creates it. You do have to create controls as usual .net object.
TextBox myNewTextBox = new TextBox() {};
// Set all initial values to it
And add this cotrol to placeholder or panel, whatever you use. Keep in mind that asp.net page events fire even if you use update panel, so in order to maintain state and events of newly created controls you have take care of creating such controls long before page's Load event fires. Here is my answer to another simialiar question.
Seeing the requirements you have:
1.) You need to use JavaScript. Since the ASP.NET will not recreate controls which are dynamically added. Dynamically added controls need to be recreated after every postback. This is the reason why your TextBoxes are Lost after every postback.
2.) You can write JavaScript code to Hide and show the textboxes for blank texts since at every button click you can call Client side functions using: OnClientClick() property of buttons.
3.) Also to Get the TextBoxes using ID property, add them in Markup( .aspx ) portion itself.
Related
i have created dynamic listboxes (4 to 10) in ASP.NET.
and my question is , How do i find the dynamically created listboxes using c#?
thanks
Sure... and i appreciate your help . below code i am using for creating dynamic LB
protected void btndyfilter_Click(object sender, EventArgs e)
{
int numberOfListBox = lbFilter.GetSelectedIndices().Length;
string lbname = lbFilter.SelectedValue;
for (int i = 0; i < numberOfListBox; i++)
{
ListBox listb = new ListBox();
ListItem lItem = new ListItem();
listb.SelectionMode = System.Web.UI.WebControls.ListSelectionMode.Multiple;
listb.Height = 150;
listb.Width = 200;
lItem.Value = i.ToString();
lItem.Text = lbname;
listb.Items.Add(lItem);
panFilter.Controls.Add(listb);
//once we created the LB dynamically i need to populate each LB with the corresponding values
connstr2 = System.Configuration.ConfigurationManager.ConnectionStrings["connstr"].ConnectionString;
conn2.ConnectionString = connstr2;
conn2.Open();
CubeCollection CubeList = conn2.Cubes;
string cb = ddlCubeList.SelectedItem.Text;
//need to remove the Hardcoded Code
foreach (Member dimem in CubeList[cb].Dimensions["Date"].Hierarchies["Calendar Date"].Levels["Date"].GetMembers())
{
ListItem Memlist = new ListItem();
Memlist.Text = dimem.UniqueName;
lbFilter.Items.Add(Memlist);
}
}
panFilter.Visible = true;
panCubeDef.Visible = true;
}
so this will create the LB i believe :)... and Inside the commented code i need to use to populate for each LB item ..perhaps it bit hardcoded which i need to remove. so i all dynamic LBs are populated then the selected items from all LBs will come into the where clause in my MDX query..hope i did not confuse you
There is 2 way either you can store dynamic control detail with dictionary or just find when you want to use it using some code like this
Control GetControlByName(string Name)
{
foreach(Control c in this.Controls)
if(c.Name == Name)
return c;
return null;
}
while generating ListBox dynamically, give ListBox ID as:
lstBoxNo1, lstBoxNo2. lstBoxNo3 etc. where 1,2,3(no) will be from count.
like
int count=1;
generate listbox control
listboxid=lastBoxNo+count;
count++
`by doing this, u have control over id's.
else use
http://stackoverflow.com/questions/3731007/using-findcontrol-to-find-control
using this link to understand findcontrol.
The points that you wont to find that dynamic controls are.
The moment you first render the page.
On every other post back.
In the case of 1, then you better keep a variable on your page that keep that creations.
In the case of 2, when you have post back, you need to store somehow the creations of your control in the page when you render it. One good place is to keep that information on the viewstate.
You can also on the post back, just to check if you have any post back valued from controls that you have named with a serial numbering starting from 1, eg You start looking if you have post back from ControlName_1, then ControlName_2, and when you not found any other value you end.
I want to set up a search functionality on my web site. The user types some information into a text box and click a search button. Upon clicking the search button, a database is searched using the text in the text box, and the results are displayed in a table. If the text in the text box matches one result from the database perfectly, rather than displaying a list of results the page is populated with detailed information about the matching result.
In order to make it easier to match a result exactly, I want to add a button next to each result which "selects" that result, filling the text box with that result's text and therefore populating the page with the details. Here's what I have.
Upon clicking the search button, after the check to see if a result is matched exactly, I create a table which contains the results and the buttons:
for(int x=0; x < res_list.Length; x++)
{
TableRow newRow = new TableRow();
TableCell textCell = new TableCell();
TableCell buttonCell = new TableCell();
buttonCell.ID = "bc" + x;
Button cellButton = new Button();
cellButton.ID = "btn" + x;
textCell.Text = res_list[x];
textCell.Attributes.Add("Width","60%");
cellButton.Text = x.ToString();
// cellButton.OnClientClick = "NameClick"; This property refers to client-side scripts, which I am not using.
cellButton.Click += new EventHandler(NameClick);
buttonCell.Controls.Add(cellButton);
newRow.Cells.Add(firstCell);
newRow.Cells.Add(buttonCell);
myTable.Rows.Add(newRow);
}
I have tried both the OnClientClick method and the Click method seen above, both of which have yielded the same results.
My NameClick function is as follows:
void NameClick(object sender, EventArgs e)
{
Button sendButton = (Button)sender;
int index = Int32.Parse(sendButton.Text);
SearchTextBox.Text = myTable.Rows[index].Cells[0].Text;
return;
}
I set up a breakpoint at the beginning of the NameClick function, and when I click one of these buttons it is never reached. Why is this function not being called by my buttons?
EDIT: I want to accomplish this without using JavaScript, if possible.
You use cellButton.OnClientClick = "NameClick";, but do you actually have a NameClick function in your javascript? If not, clicking the button will cause a JS error which will probably block the postback.
Other than that, it is advisable to assign explicit ID's to controls which you create programatically. Otherwise the autogenerated ID's may change on postback, which will prevent control events from firing.
Something like the following should work (not tested):
myTable.ID = "someid";
for (int x=0; x < res_list.Length; x++)
{
TableRow newRow = new TableRow();
newRow.ID = "r" + x;
TableCell textCell = new TableCell();
TableCell buttonCell = new TableCell();
buttonCell.ID = "bc" + x;
Button cellButton = new Button();
cellButton.ID = "btn" + x;
textCell.Text = res_list[x];
textCell.Attributes.Add("Width","60%");
cellButton.Text = x.ToString();
//cellButton.OnClientClick = "NameClick"; // not needed unless you have actual JS for it
cellButton.Click += new EventHandler(NameClick);
buttonCell.Controls.Add(cellButton);
newRow.Cells.Add(firstCell);
newRow.Cells.Add(buttonCell);
myTable.Rows.Add(newRow);
}
cellButton.OnClientClick should point to a client-side function, i.e. JavaScript. Do you have a JS function somewhere?
If the answer is no, then we've found your problem. You should create one. It will be helpful to set your ClientIDMode property of your dynamically generated controls to Static or Predictable, so your JS function can easiliy access them.
Do you need assistance with the JS function?
when you click on the button, the page start the life cycle again and your control Does not exist in the page you need to create the control again or save it in the viewstate or use control state
when he call back in the life cycle
in the page life cycle event SaveControlState, loadControlState
if you want to create a javascript click event you need to make sure that the control doesnt call to server side event for this in the javascript function you need to return false
you have to add this event in your asp syntax for button.
<asp:Button runat="server " OnClick="ButtonClick"/>
The current form is here. It is not complete, and only a couple options will work.
Select "Image CD" and then any resolution and click "Add to Order." The order will be recorded on the server-side, but on the client-side I need to reset the product drop-down to "{select}" so that the user will know that they need to select another product. This is consistant with the idea that the sub-selections disappear.
I don't know whether I should be using ASP postback or standard form submittal, and most of the fields need to be reset when the user adds an item to the order.
I'd use Response.Redirect(Request.RawUrl) method to reset the form data from the server side.
A little explanation: this is PRG design pattern
Used to help avoid certain duplicate
form submissions and allow user agents
to behave more intuitively with
bookmarks and the refresh button.
A workaround for this question:
necessary data may be stored in Session for example. This means we getting the data with the first POST, putting it to the storage, performing redirect and getting it back.
In the pageload event on the form, you need to add something simalar to this:
if (IsPostBack)
{
//Proccess the order here
ProductOption.SelectedIndex = 0;
}
That will allow you to process the order, but then start over the order form.
The simplest means would be a recursive function that forks on the type of control
private void ResetControls( Control control )
{
if ( control == null)
return;
var textbox = control As TextBox;
if ( textbox != null )
textbox.Text = string.Empty;
var dropdownlist = control as DropDownList;
if ( dropdownlist != null )
dropdownlist.SelectedIndex = 0; // or -1
...
foreach( var childControl in controlControls )
ResetControls( childControl );
}
You would this call this function in your Load event by passing this. (This is presuming you want to reset more than a single control or small list of controls).
I have a listView control which is bound to an object datasource. In the ListView1_ItemDataBound event, I am generating some dynamic controls. I do this because depending on a particular column value, i might need to generate textbox, radio button, check box etc.
Some code here:
ListViewDataItem item = (ListViewDataItem)e.Item;
typez = Convert.ToInt32(DataBinder.Eval(item.DataItem,"Type").ToString());
if (typez == 1) //1 means generate radibutton
{
string[] options = DataBinder.Eval(item.DataItem, "QuestionDetail").ToString().Split(new string[] { delimiter }, StringSplitOptions.None);
questionID = Convert.ToInt32(DataBinder.Eval(item.DataItem, "Question_ID").ToString());
int optionCount = 1;
RadioButtonList rbl = new RadioButtonList();
//set ID for the radiobtnList to the questionid no.
rbl.ID = "mcq_" + questionID;
foreach (string s in options)
{
//adds the MCQ options to list item
ListItem li = new ListItem(Util.GetAlphabet(optionCount).ToUpper() + ". " + s, Util.GetAlphabet(optionCount).ToUpper(), true);
rbl.Items.Add(li);
optionCount++;
}
//PlaceHolder PlaceHolder1 = (PlaceHolder)e.Item.FindControl("PlaceHolder1");
PlaceHolder1.Controls.Add(rbl);
I have DataPager also. When I go to the next page I want to somehow capture the user response in the previous page. Otherwise, all the user response is lost. I tried using ListView1_PagePropertiesChanging event. But here I somehow do not seem to get the dynamic controls in the page.
I need to get the radio button selected value so that I can save it or put in some session variable so that when user comes back to this page he can see his previuos values.
Could someone please suggest some insight on what I am doing wrong.
Problem is that you have to create controls in OnInit, then ViewState persister can do it's job. If you do it after OnInit, in ItemDataBound, when Postback is triggered, controls doesn't exists and their's viewstate isn't deserialized.
To access values of radio buttons and get selected one, you have to look at Request.Form dictionary and find it.
I want to instantly update a status line indicating the number of checked checkboxes across all pages of an asp.net gridview. Right now I am only ably to count the number of checkboxes that are checked on the current gridview page.
Here is my code:
$(document).ready(initAll);
function initAll(){
countChecked();
$(".activeBoxes").click(countChecked);
}
function countChecked() {
var n = $(".activeBoxes input:checked").length;
$("#checkboxStatus").text(n + (n == 1 ? " vehicle is" : " vehicles are") + " selected on this page. ");
if( n == 0){
$(".activateButton").hide();
$("#checkboxStatus").hide();
}else{
$("#checkboxStatus").show();
$(".activateButton").show();
}
}
Keep a hidden text field on your page and everytime you check a box, call a javascript method that will write the 'id' of the checkbox to the hidden field. Each time you postback your page, serialise the hidden field's value to the session in your desired objects structure (be it objects, hash table, array etc).
Upon rendering the page, each checkbox can check the session object structure (that you have created before) and determine if the state of the checkbox was last checked or not.
You could use JQuery to loop through all checkboxes on the page and increment a counter if the checkbox is checked.
You can track the total selection in viewstate (or something similar) on page change. I did something similar tracking the selected row ID's in an array. In my case I had to re-check the items when they returned to the page. Additionally if you allow sorting the selection may move across pages.
Edit: Sorry this doesn't actually your Jquery question, but maybe it will help...
What you're missing is removing the ID. When checking rows and tempid is not checked make sure it is not in saveids.
Do you know that Google is your friend?
Selecting CheckBoxes Inside GridView Using JQuery
The WML Video
And without JQuery but for more perfectionist behavior (like the image below), try this link
alt text http://www.gridviewguy.com/ArticleImages/GridViewCheckBoxTwistAni.gif
I am using a viewstate to keep track of all checked items across all pages and rechecking them upon returning to the page.
I will have to add my viewstate value to the page total and somehow subtract overlapping totals. Since my jquery does not include an id, this will be tricky.
protected ArrayList savedIds;
if (ViewState["SavedIds"] == null) savedIds = new ArrayList();
else savedIds = (ArrayList)ViewState["SavedIds"];
List<int> activateList = new List<int>();
foreach (GridViewRow tt in GridView2.Rows)
{
CheckBox cb = (CheckBox)tt.FindControl("ActivateItem");
HiddenField id = (HiddenField)tt.FindControl("IdField");
if (cb.Checked)
{
int tempId = 0;
string tempId2 = id.Value.ToString();
int.TryParse(tempId2, out tempId);
activateList.Add(tempId);
}
}
foreach (int activateId in activateList)
{
if (!savedIds.Contains(activateId.ToString())) savedIds.Add(activateId.ToString());
}
ViewState["SavedIds"] = savedIds;