adding textboxes at runtime in asp.net

i need to create textboxes dynamically as user specifies the no..actually there are two textboxes in a row..user specifies no of rows needed.. as s开发者_StackOverflow社区pecified textboxes(two per row) should be added to the form and also i need to read the text entered later....what is the best method??

If the number of textboxes is constant but the number of rows is dynamic, then use a GridView. Then bind the gridview to a list or array of the length that the user specified. The gridview will then render the specified rows and you can get the values from the textboxes on postback.

Control.Controls.Add(new TextBox());

Notes:

• "Control" will obviously be the parent control of where the textboxes go in your case, e.g. an control.
• You'll need to add the controls on CreateChildControls or on Page_Init so they are added at the right point in the page lifetime.

To add controls to an aspx page dynamically, follow these steps.

First, add a placeholder on the ASPX page:

<asp:PlaceHolder runat="server" id="AssessCanvas" />

Mine is called "AssessCanvas". Next, add the controls themselves. Here is code that I use in methods called by Page_Load to create a label and a text box. The label is a prompt for "Weight:" and the text box is used to enter a weight value (in the example, I am also including a value for weight when I create the box):

Label aLbl = new Label { Text = "Weight: ", ID = ("WSLabel" + counter) };
counter++;
AssessCanvas.Controls.Add(aLbl);

TextBox aBox = new TextBox { ID = "XTest1", Columns = 5, Text = weight.ToString("##0.0"), Width = 50 };
AssessCanvas.Controls.Add(aBox);

I use "WSLabelN" (where N is a number) to give a unique ID to each label. Because I'll want to scan all of my text boxes to pull their contents when the form is submitted, I give each of them an ID of the form "XTestN" (where N is a unique identifier for each field - here the "XTest1" tells me that this is the weight field).

When I'm ready to handle the form submit, I do this:

// Look at each key submitted with the form - *some* of these will be my input text boxes
foreach (string aStr in form.AllKeys)
{
    // Is this an input text box?  Yes if it has "XTest" in it somewhere.
    int position = aStr.IndexOf("XTest");
    if (position > 0)
    {
        // The data entry fields for each input box follows the format: <ASP.NET Prefix>XTest<TID>
        // Here I get the tid so I know what to do with the value that was entered 
        short tid = BSDIUtil.StrToIntDef(aStr.Substring(position + 5));
        switch (tid)
        {
            case 1: SaveWeight(BSDIUtil.StrToFloatDef(form.Get(aStr))); break;
            case 2: SaveJP3P1(BSDIUtil.StrToFloatDef(form.Get(aStr))); break;
            ... etc...
         }
     }
}

In my system, I often have to place several fields on the page to collect values for one testing item (the system here comes from a fitness testing page). For example, "SaveJP3P1" above isn't called as shown because it actually pulls data from nine different fields. I simplified it for the example for obvious reasons.

This approach gives you a great deal of flexibility. In my full page, I have check-boxes, header labels (e.g. a label with HTML/CSS formatting in addition to the label text), and even several DIVS for fitness tests with multiple panels for their input. And all of it is done dynamically. Obviously, a grid wouldn't work and neither would just adding a control to the control tree as others have suggested.