ASP.NET Tutorial/ASP.net Controls/TextBox

Материал из .Net Framework эксперт
Версия от 15:00, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
(разн.) ← Предыдущая | Текущая версия (разн.) | Следующая → (разн.)
Перейти к: навигация, поиск

asp:TextBox changed event (C#)

   <source lang="csharp">

File: Default.aspx <%@ Page language="c#" Inherits="EventTracker" CodeFile="Default.aspx.cs" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" 

"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">

<html xmlns="http://www.w3.org/1999/xhtml"> <head id="Head1" runat="server"> 

 <title>Event Tracker</title>

</head> <body> 

 <form id="Form1" runat="server">

Controls being monitored for change events:

     <asp:TextBox ID="txt" 
                  runat="server" 
                  AutoPostBack="true"
                  OnTextChanged="CtrlChanged" />
     


     <asp:CheckBox ID="chk" 
                   runat="server" 
                   AutoPostBack="true"
                   OnCheckedChanged="CtrlChanged"/>
     


     <asp:RadioButton ID="opt1" runat="server" GroupName="Sample"
      AutoPostBack="true" OnCheckedChanged="CtrlChanged"/>
     <asp:RadioButton ID="opt2" runat="server" GroupName="Sample"
      AutoPostBack="true" OnCheckedChanged="CtrlChanged"/>

List of events:

     <asp:ListBox ID="lstEvents" runat="server" Width="355px"
      Height="305px" />
      

 </form>

</body> </html>

File: Default.aspx.cs using System; using System.Collections; using System.ruponentModel; using System.Data; using System.Drawing; using System.Web; using System.Web.SessionState; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.HtmlControls;

public partial class EventTracker : System.Web.UI.Page { 

 protected void Page_Load(object sender, System.EventArgs e)
 {
    Log("<< Page_Load >>");
 }
 private void Log(string entry)
 {
   lstEvents.Items.Add(entry);
   lstEvents.SelectedIndex = lstEvents.Items.Count - 1;
 }
 protected void Page_PreRender(object sender, System.EventArgs e)
 {
   Log("Page_PreRender");
 }
 protected void CtrlChanged(Object sender, EventArgs e)
 {
   string ctrlName = ((Control)sender).ID;
   Log(ctrlName + " Changed");
 }

}</source>


Bind string value to asp:textBox (VB.net)

   <source lang="csharp">

<script runat="server"> 

  dim strName as String = "A"
  dim myArray() as String = {"Hello", "World"}
  dim myString as String = "AA"
  sub Page_Load(Sender as Object, e as EventArgs)
     Page.DataBind()
  end sub

</script> <html> 

  <form runat="server">
  My Name is <%# strName %>
  <asp:Listbox datasource="<%# myArray %>" runat="server" />
 
  <asp:Textbox text="<%# myString.ToString %>" runat="server" />
  </form>

</html></source>


Check form input value and report error in case of empty input (VB.net)

   <source lang="csharp">

<%@ Page Language="VB" %> <script runat="server"> 

  sub Submit(Sender as Object, e as EventArgs)
     lblMessage.Text = ""
     if tbName.Text = "" then
        lblMessage.Text = "You forgot your name!
"
     end if
     if tbPhone.Text = "" then
        lblMessage.Text += "You forgot your phone!
"
     end if
     if tbEmail.Text = "" then
        lblMessage.Text += "You forgot your email!
"
     end if
     
     if lblMessage.Text = "" then
        lblMessage.Text = "Your information has been " & _
           "submitted!"
     end if
     
     
  end sub

</script> <html><body> 

  Please enter the following information.
  <asp:Label id="lblMessage" runat="server"/>
  <form runat="server">
Name* 
           <asp:TextBox id="tbName" runat="server"/>
Address 
           <asp:TextBox id="tbAddress" runat="server"/>
Phone* (area code first) 
           <asp:TextBox id="tbPhone" runat="server"/>
Fax (area code first) 
           <asp:TextBox id="tbFax" runat="server"/>
Email* 
           <asp:TextBox id="tbEmail" runat="server"/>

           <asp:Button id="btSubmit" runat="server" Text="Submit" OnClick="Submit" />

     An asterisk (*) indicates a required field.
  </form>

</body></html></source>


Convert input in TextBox into decimal

   <source lang="csharp">

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> 

   <title>Simple Calculator</title>

</head> <body> 

   <form id="form1" runat="server">

The Simple Calculator

       First number:
       <asp:TextBox ID="txtFirst" runat="server" />  
       


       Second number:
       <asp:TextBox ID="txtSecond" runat="server" />  
       


       <asp:Button ID="btnAdd" runat="server"   
           OnClick="btnAdd_Click" Text="Add" />
       


       The answer is:
       <asp:Label ID="lblAnswer" runat="server" />  

   </form>

</body> </html> File: Default.aspx.cs using System; using System.Data; using System.Configuration; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls;

public partial class _Default : System.Web.UI.Page { 

   protected void btnAdd_Click(object sender, EventArgs e)
   {
       decimal a = decimal.Parse(txtFirst.Text);
       decimal b = decimal.Parse(txtSecond.Text);
       decimal c = a + b;
       lblAnswer.Text = c.ToString();
   }

}</source>


Extrapolate date values from the typed text

   <source lang="csharp">

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" 

   Inherits="Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> 

   <title>Extension Methods</title>

</head> <body> 

       <form id="form1" runat="server">
           <asp:TextBox ID="TextBox1" runat="server" /> 
           <asp:Button ID="Button1" runat="server" Text="Test" OnClick="Button1_Click" />

Next day is

           <asp:Label ID="Label1" runat="server" /> 
       </form>

</body> </html>

File: Default.aspx.cs using System; using System.Data; using System.Configuration; using System.Collections; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; using System.Collections.Generic; using System.Text; public static class StringExtensions 

   {
       public static bool IsInt32(this string content)
       {
           int number;
           bool result = Int32.TryParse(content, out number);
           return result;
       }
       public static bool IsDate(this string content)
       {
           DateTime date;
           bool result = DateTime.TryParse(content, out date);
           return result;
       }
       public static DateTime ToDate(this string content)
       {
           DateTime date;
           bool result = DateTime.TryParse(content, out date);
           if (result)
               return date;
           else
               return DateTime.MinValue;
       }
       public static int ToInt32(this string content)
       {
           int number;
           bool result = Int32.TryParse(content, out number);
           if (result)
               return number;
           else
               return Int32.MinValue;
       }
   }

public partial class Default : System.Web.UI.Page { 

   public void Button1_Click(object sender, EventArgs e)
   {
       string content = TextBox1.Text;
       if (content.IsDate())
       {
           DateTime date = content.ToDate();
           Label1.Text = date.AddDays(1).ToString("dd MMMM yyyy");
       }
       else
       {
           Label1.Text = "Not a valid date.";
       }
   }

}</source>


Get input value from asp:textbox (VB.net)

   <source lang="csharp">

<%@Page Language="VB" %> <script runat="server"> Sub tbMessage_Change(Sender As Object,E As EventArgs) 

   lblMessage.Text = "Hello" + tbMessage.Text

End Sub </script> <html> <body> 

    <%Response.Write("Our First Page")%>
   <form runat="server">
        Please enter your name:
        <asp:textbox id="tbMessage" OnTextChanged="tbMessage_Change" runat=server/>
        <asp:button id="btSubmit" Text="Submit" runat=server/>
        <asp:label id="lblMessage" font-size="20pt" runat=server/>
   </form>

</body> </html></source>


Important properties, method and event of TextBox control

   <source lang="csharp">

AccessKey: specify a key that navigates to the TextBox control. AutoCompleteType: associate an AutoComplete class with the TextBox control. AutoPostBack: post the form containing the TextBox back to the server automatically when the contents of the TextBox is changed. Columns: specify the number of columns to display. Enabled: disable the text box. MaxLength: specify the maximum length of data that a user can enter in a text box (does not work when TextMode is set to Multiline). ReadOnly: prevent users from changing the text in a text box. Rows: specify the number of rows to display. TabIndex: specify the tab order of the text box. Wrap: specify whether text word-wraps when the TextMode is set to Multiline. Focus: set the initial form focus to the text box. TextChange: Raised on the server when the contents of the text box are changed.

<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> 

   protected void txtSearch_TextChanged(object sender, EventArgs e)
   {
       lblSearchResults.Text = "Search for: " + txtSearch.Text;
   }

</script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server"> 

   <title>TextBox AutoPostBack</title>

</head> <body> 

   <form id="form1" runat="server">

   <asp:Label
       id="lblSearch"
       Text="Search:"
       Runat="server" />
   <asp:TextBox
       id="txtSearch"
       AutoPostBack="true"
       OnTextChanged="txtSearch_TextChanged"
       Runat="server" />

   <asp:Label
       id="lblSearchResults"
       Runat="server" />

   </form>

</body> </html></source>


Set AutoCompleteType

   <source lang="csharp">

<%@ Page Language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server"> 

   <title>Show AutoComplete</title>

</head> <body> 

   <form id="form1" runat="server">

   <asp:Label
       id="lblFirstName"
       Text="First Name:"
       AssociatedControlID="txtFirstName"
       Runat="server" />
   

   <asp:TextBox
       id="txtFirstName"
       AutoCompleteType="FirstName"
       Runat="server" />    
   

    
   <asp:Label
       id="lblLastname"
       Text="Last Name:"
       AssociatedControlID="txtLastName"
       Runat="server" />
   

   <asp:TextBox
       id="txtLastName"
       AutoCompleteType="LastName"
       Runat="server" />    
   


   <asp:Button
       id="btnSubmit"
       Text="Submit"
       Runat="server" />    
   

   </form>

</body> </html></source>


Set textbox text value in button action

   <source lang="csharp">

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="MyPage" %> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> 

   <title>Untitled Page</title>

</head> <body> 

   <form id="form1" runat="server">

       <asp:Label ID="Label1" runat="server" Text="The city name"></asp:Label>
       <asp:Label ID="note" runat="server" Text="Label"></asp:Label>
       <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
       <asp:Button ID="Button1" runat="server" Text="Display" />

   </form>

</body> </html>

File: Default.aspx.vb

Partial Class MyPage 

   Inherits System.Web.UI.Page
   Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
       If Me.TextBox1.Text = "" Then
           Me.note.Text = "Please input the city name"
       Else
           Me.note.Text = "The input is:" & Me.TextBox1.Text
       End If
   End Sub

End Class</source>


Set the focus to a TextBox

   <source lang="csharp">

<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> 

   void Page_Load()
   {
       txtFirstName.Focus();
   }

</script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server"> 

   <title>TextBox Focus</title>

</head> <body> 

   <form id="form1" runat="server">

   <asp:Label
       id="lblFirstName"
       Text="First Name:"
       AssociatedControlID="txtFirstName"
       Runat="server" />
   

   <asp:TextBox
       id="txtFirstName"
       AutoCompleteType="FirstName"
       Runat="server" />
   


   <asp:Label
       id="lblLastname"
       Text="Last Name:"
       AssociatedControlID="txtLastName"
       Runat="server" />
   

   <asp:TextBox
       id="txtLastName"
       AutoCompleteType="LastName"
       Runat="server" />
   


   <asp:Button
       id="btnSubmit"
       Text="Submit"
       Runat="server" />

   </form>

</body> </html></source>


Show AutoComplete

   <source lang="csharp">

<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server"> 

   <title>Show AutoComplete</title>

</head> <body> 

   <form id="form1" runat="server">

   <asp:Label
       id="lblFirstName"
       Text="First Name:"
       AssociatedControlID="txtFirstName"
       Runat="server" />
   

   <asp:TextBox
       id="txtFirstName"
       AutoCompleteType="FirstName"
       Runat="server" />
   


   <asp:Label
       id="lblLastname"
       Text="Last Name:"
       AssociatedControlID="txtLastName"
       Runat="server" />
   

   <asp:TextBox
       id="txtLastName"
       AutoCompleteType="LastName"
       Runat="server" />
   


   <asp:Button
       id="btnSubmit"
       Text="Submit"
       Runat="server" />

   </form>

</body> </html></source>


TextBox can display different types of input fields depending TextMode property

   <source lang="csharp">

The TextMode property accepts the following three values: SingleLine: Displays a single-line input field. MultiLine: Displays a multi-line input field. Password: Displays a single-line input field in which the text is hidden. <%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server"> 

   <title>Show TextBox</title>

</head> <body> 

   <form id="form1" runat="server">

   <asp:TextBox
       id="txtUserName"
       TextMode="SingleLine"
       Runat="server" />
   


   <asp:TextBox
       id="txtPassword"
       TextMode="Password"
       Runat="server" />
   


   <asp:TextBox
       id="txtComments"
       TextMode="MultiLine"
       Runat="server" />

   </form>

</body> </html></source>


Use Cint to convert input value in asp:textbox to integer (VB)

   <source lang="csharp">

<%@ Page Language="VB" %> <script runat="server"> 

  Sub btSubmit_Click(Sender As Object, E As EventArgs)
    lblMessage.Text = Cint(tbNumber1.Text) * Cint(tbNumber2.Text)
  End Sub

</script> <HTML> <HEAD> </HEAD> <BODY> <form runat="server"> 

   Number 1: <asp:textbox id="tbNumber1" runat=server/>
   Number 2: <asp:textbox id="tbNumber2" runat=server/>
   <asp:button id="btSubmit" Text="Submit" OnClick="btSubmit_Click" runat=server/>
   <asp:label id="lblMessage" font-size="20pt" runat=server/>

</form> </BODY> </HTML></source>


Use Convert.ToInt32 to convert input value in asp:textbox to integer (C#)

   <source lang="csharp">

<%@ Page Language="C#" %> <script runat="server"> 

 void btSubmit_Click(Object Sender, EventArgs e) {
    lblMessage.Text = (Convert.ToInt32(tbNumber1.Text) * Convert.ToInt32(tbNumber2.Text)).ToString();
 }

</script> <HTML> <HEAD> </HEAD> <BODY> <form runat="server"> 

   Number 1: <asp:textbox id="tbNumber1" runat=server/>
   Number 2: <asp:textbox id="tbNumber2" runat=server/>
   <asp:button id="btSubmit" Text="Submit" OnClick="btSubmit_Click" runat=server/>
   <asp:label id="lblMessage" font-size="20pt" runat=server/>

</form> </BODY> </HTML></source>


Use if statement to check form input data (VB.net)

   <source lang="csharp">

<script runat="server"> 

  sub Submit(Sender as Object, e as EventArgs)
     if tbFName.Text <> "" and not IsNumeric(tbFName.Text) then
        lblMessage.Text = "First name is incorrect!"
     end if
     if tbLName.Text <> "" and not IsNumeric(tbLName.Text) then
        lblMessage.Text = "Last name is incorrect!"
     end if
     if tbAddress.Text <> "" then
        lblMessage.Text = "Address is incorrect!"
     end if

     if tbCity.Text <> "" and not IsNumeric(tbCity.Text) then
        lblMessage.Text = "City is incorrect!"
     end if

     if tbState.Text <> "" and not IsNumeric(tbState.Text) then
       lblMessage.Text = "State is incorrect!"
     end if
 
     if tbZIP.Text <> "" and IsNumeric(tbZIP.Text) then
       lblMessage.Text = "ZIP is incorrect!"
     end if
 
     if tbPhone.Text <> "" then
       lblMessage.Text = "Success!"
     else
       lblMessage.Text = "Phone is incorrect!"
     end if
  end sub

</script> <html><body> 

  <form runat="server">
     <asp:Label id="lblMessage" runat="server" />

     <asp:Panel id="Panel1" runat="server">
              First and last name:
              <asp:TextBox id="tbFName" runat="server" />
              <asp:TextBox id="tbLName" runat="server" />
              Email:
              <asp:TextBox id="tbEmail" 
                 runat="server" />
              Address:
              <asp:TextBox id="tbAddress" 
                 runat="server" />
              City, State, ZIP:
              <asp:TextBox id="tbCity" 
                 runat="server" />,
              <asp:TextBox id="tbState" runat="server"
                 size=2 /> 
              <asp:TextBox id="tbZIP" runat="server"
                 size=5 />
              Phone:
              <asp:TextBox id="tbPhone" runat="server"
                 size=11 />
              <asp:Button id="btSubmit" runat="server" 
                 text="Add" OnClick="Submit"/>
     </asp:Panel>
  </form>

</body></html></source>

Источник — «http://nfex.ru/index.php?title=ASP.NET_Tutorial/ASP.net_Controls/TextBox&oldid=3375»