ASP.NET FAQ - TextBox

Refer to the link ASP.NET: TextBox and EnableViewState=’False’

(I don’t understand ‘tyring to insert/update data’, ‘webcontrol is not associated with it’s property’!)
//
if you write code using parametrized query as
paramxxx.value = textbox1
it’ll show above error
to resolve it it should be
paramxxx.value =textbox1.text

//This kind of error message can occur when you are trying to insert/update data or any kind of operation which involves textbox/dropdownlist
The issue occurs if the webcontrol is not associated with its property

May be you have not associated the appropriate property of the control
i.e textBox1.Text
or dropdownlist1.SelectedItem.Value

For security reason, TextBox with TextMode=’Password’ setting cannot be assigned or populated via the Text property on Page_Load or PostBack event.

It’s not recommend for to prefill a ‘Password’ type TextBox with the(‘***’) characters, though below is the solution to achieve this.

VB.NET

ViewState('Pwd')=TextBox1.Text ;
TextBox1.Attributes.Add('value', ViewState('Pwd').ToString ()) ;

C#

ViewState['Pwd']=TextBox1.Text ;
TextBox1.Attributes.Add('value', ViewState['Pwd'].ToString ()) ;

For type Casting apply the following steps

VB.NET

dim aprtxt as string
aprtxt= CType(e.Item.FindControl('txtapr'), TextBox)

C#

string aprtxt;
aprtxt = (TextBox) e.Item.FindControl['txtapr'];

<asp:TextBox id='txtNumber' Runat='server' />
<asp:RegularExpressionValidator ID='vldNumber' ControlToValidate='txtNumber' Display='Dynamic' ErrorMessage='Not a number' ValidationExpression='(^([0-9]*|\d*\d{1}?\d*)$)' Runat='server'>
</asp:RegularExpressionValidator>

<asp:TextBox id='TextBox1' style='Z-INDEX: 101; LEFT: 0px; POSITION: absolute; TOP: 112px' runat='server' TextMode='MultiLine'></asp:TextBox>
<asp:RegularExpressionValidator id='RegularExpressionValidator1' style='Z-INDEX: 102; LEFT: 216px; POSITION: absolute; TOP: 112px'
	runat='server' ErrorMessage='MaxLength is 20' ControlToValidate='TextBox1' 	ValidationExpression='^\w{1,20}
>
</asp:RegularExpressionValidator>

<script lang='javascript'> 
function CheckFunction() 
{ 
if (document.getElementById(’<%=textbox2.ClientID%>’).value == '') 
{ 
	alert('Please enter a value'); 
	return; 
} 
} 
</script> 



<asp:textbox id='textbox2' runat='Server'></asp:textbox> 
<input type=button id='btn1' onclick='javascript:CheckFunction();' value='Click'>

<asp:TextBox id='TextBox1' dir=rtl runat='server'></asp:TextBox>

<asp:TextBox id='TextBox1' BackColor =<%#colCon.ConvertFromString(bgcolor)%> runat='server'>
</asp:TextBox>

VB.NET

Protected colCon As New System.Drawing.ColorConverter
Protected bgcolor As String = '#556600'

’In Page_Load
Page.DataBind()

C#

protected  System.Drawing.ColorConverter colCon =new System.Drawing.ColorConverter();
protected string bgcolor    = '#556600';

//In Page_Load
Page.Databind();

Product ID : <asp:TextBox id='TextBox1' style='Z-INDEX: 101; LEFT: 80px; POSITION: absolute; TOP: 64px' runat='server'></asp:TextBox>
Product Name:<asp:TextBox id='TextBox2' style='Z-INDEX: 102; LEFT: 80px; POSITION: absolute; TOP: 112px' runat='server'></asp:TextBox>

VB.NET

’Populate the DataSet
’...

’Display in TextBoxes using Column Name
TextBox1.Text = ds.Tables (0).Rows(0)('ProductId').ToString ();
TextBox2.Text =ds.Tables (0).Rows(0)('ProductName').ToString (); 

’Display in TextBoxes using Column Index
TextBox1.Text = ds.Tables (0).Rows(0)(0).ToString ();
TextBox2.Text =ds.Tables (0).Rows(0)(1).ToString (); 

C#

//Populate the DataSet
//...

//Display in TextBoxes using Column Name
TextBox1.Text = ds.Tables [0].Rows[0]['ProductId'].ToString ();
TextBox2.Text =ds.Tables [0].Rows[0]['ProductName'].ToString (); 

//Display in TextBoxes using Column Index
TextBox1.Text = ds.Tables [0].Rows[0][0].ToString ();
TextBox2.Text =ds.Tables [0].Rows[0][1].ToString (); 

Id : <asp:TextBox id='TextBox1' style='Z-INDEX: 102; LEFT: 128px; POSITION: absolute; TOP: 32px' runat='server'></asp:TextBox>
Name : <asp:TextBox id='TextBox2' style='Z-INDEX: 103; LEFT: 128px; POSITION: absolute; TOP: 72px' runat='server'></asp:TextBox>

VB.NET

Dim cn As SqlConnection
Dim cmd As SqlCommand
Dim rdr As SqlDataReader

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
	’ Put user code to initialize the page here
	Try
		cn = New SqlConnection('server=localhost;uid=sa;pwd=;database=northwind')
		cmd = New SqlCommand('select * from Products where productid =1', cn)
		cn.Open()
		rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection)
		rdr.Read()
		TextBox1.Text = rdr('ProductId').ToString()
		TextBox2.Text = rdr('ProductName').ToString()
	Catch ex As Exception
		Response.Write(ex.Message.ToString())
	Finally
		rdr.Close()
		cn.Close()
	End Try
End Sub 

C#

SqlConnection cn ;
SqlCommand cmd ;
SqlDataReader rdr ; 
private void Page_Load(object sender, System.EventArgs e)
{
	// Put user code to initialize the page here
	try
	{
		cn = new SqlConnection('server=localhost;uid=sa;pwd=;database=northwind');
		cmd = new SqlCommand( 'select * from Products where productid=1 ', cn);
		cn.Open();
		rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection );
		rdr.Read ();
		TextBox1.Text =rdr['ProductId'].ToString ();
		TextBox2.Text =rdr['ProductName'].ToString ();
	}
	catch (Exception ex)
	{
		Response.Write (ex.Message.ToString ());
	}
	finally
	{
		rdr.Close();
		cn.Close();
	}
}

<asp:PlaceHolder id='PlaceHolder1' runat='server'></asp:PlaceHolder>

VB.NET

Dim textboxes(5) As TextBox
Dim i As Integer
For i = 0 To 4
   	textboxes(i) = New TextBox()
	textboxes(i).ID = 'TextBox' + i
   	textboxes(i).AutoPostBack = True
   	PlaceHolder1.Controls.Add(textboxes(i))
Next 

C#

TextBox[] textboxes = new TextBox[5]; 
for (int i=0; i<5; i++) 
{ 
	textboxes[i] = new TextBox(); 
	textboxes[i].ID = 'TextBox' + i; 
	textboxes[i].AutoPostBack = true; 
	PlaceHolder1.Controls.Add(textboxes[i]); 
}

You can use the TextBox webserver control and set the TextMode = MultiLine

VB.NET

Dim dt As DateTime = DateTime.Parse(TextBox1.Text)

C#

DateTime dt  = DateTime.Parse(TextBox1.Text);

By default Date.Parse check the date as MDY format
Refer DateTime.Parse for a specified Date Format.

VB.NET

Textbox1.Text= dsData.Tables(0).Rows(0)('FieldName').ToString()

C#

TextBox1.Text=dsData.Tables[0].Rows[0]['FieldName'].ToString();

VB.NET

Int32.Parse(TextBox1.Text)

C#

Int32.Parse(TextBox1.Text);

VB.NET

TextBox1.Width = Unit.Pixel(100)

C#

TextBox1.Width = Unit.Pixel(100);

VB.NET

Dim ctl As Control
For Each ctl In Page.Controls(1).Controls
            If TypeOf ctl Is TextBox Then
                CType(ctl, TextBox).Text = ''
            End If
Next

C#

foreach (Control ctl in Page.Controls[1].Controls )
{
	TextBox tb = ctl as TextBox;
	if (tb!=null)
	{
	tb.Text = '' ;
	}
}

Note: Page.Controls[1]=> control is within the

VB.NET

TextBox1.Style('text-align')='right'

C#

TextBox1.Style['text-align']='right';