TextBox.Columns-Eigenschaft
Ruft die Anzeigebreite des Textfelds in Zeichen ab oder legt diese fest.
Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)
Syntax
'Declaration
Public Overridable Property Columns As Integer
'Usage
Dim instance As TextBox
Dim value As Integer
value = instance.Columns
instance.Columns = value
public virtual int Columns { get; set; }
public:
virtual property int Columns {
int get ();
void set (int value);
}
/** @property */
public int get_Columns ()
/** @property */
public void set_Columns (int value)
public function get Columns () : int
public function set Columns (value : int)
Eigenschaftenwert
Die Anzeigebreite des Textfelds in Zeichen. Der Standardwert ist 0 (null) und bedeutet, dass die Eigenschaft nicht festgelegt wurde.
Ausnahmen
| Ausnahmetyp | Bedingung |
|---|---|
Der angegebene Wert ist kleiner als 0 (null). |
Beispiel
Im folgenden Codebeispiel wird veranschaulicht, wie mit der Columns-Eigenschaft eine Breite von 2 Zeichen für das TextBox-Steuerelement festgelegt werden kann.
<%@ Page Language="VB" AutoEventWireup="True" %>
<html>
<head>
<script runat="server">
Protected Sub AddButton_Click(sender As Object, e As EventArgs)
Dim Answer As Integer
Answer = Convert.ToInt32(Value1.Text) + Convert.ToInt32(Value2.Text)
AnswerMessage.Text = Answer.ToString()
End Sub
</script>
</head>
<body>
<form runat="server">
<h3> TextBox Example </h3>
<table>
<tr>
<td colspan="5">
Enter integer values into the text boxes. <br>
Click the Add button to add the two values. <br>
Click the Reset button to reset the text boxes.
</td>
</tr>
<tr>
<td colspan="5">
</td>
</tr>
<tr align="center">
<td>
<asp:TextBox ID="Value1"
Columns="2"
MaxLength="3"
Text="1"
runat="server"/>
</td>
<td>
+
</td>
<td>
<asp:TextBox ID="Value2"
Columns="2"
MaxLength="3"
Text="1"
runat="server"/>
</td>
<td>
=
</td>
<td>
<asp:Label ID="AnswerMessage"
runat="server"/>
</td>
</tr>
<tr>
<td colspan="2">
<asp:RequiredFieldValidator
ID="Value1RequiredValidator"
ControlToValidate="Value1"
ErrorMessage="Please enter a value.<br>"
Display="Dynamic"
runat="server"/>
<asp:RangeValidator
ID="Value1RangeValidator"
ControlToValidate="Value1"
Type="Integer"
MinimumValue="1"
MaximumValue="100"
ErrorMessage="Please enter an integer <br> between than 1 and 100.<br>"
Display="Dynamic"
runat="server"/>
</td>
<td colspan="2">
<asp:RequiredFieldValidator
ID="Value2RequiredValidator"
ControlToValidate="Value2"
ErrorMessage="Please enter a value.<br>"
Display="Dynamic"
runat="server"/>
<asp:RangeValidator
ID="Value2RangeValidator"
ControlToValidate="Value2"
Type="Integer"
MinimumValue="1"
MaximumValue="100"
ErrorMessage="Please enter an integer <br> between than 1 and 100.<br>"
Display="Dynamic"
runat="server"/>
</td>
<td>
 
</td
</tr>
<tr align="center">
<td colspan="4">
<asp:Button ID="AddButton"
Text="Add"
OnClick="AddButton_Click"
runat="server"/>
</td>
<td>
</td>
</tr>
</table>
</form>
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="True" %>
<html>
<head>
<script runat="server">
protected void AddButton_Click(Object sender, EventArgs e)
{
int Answer;
Answer = Convert.ToInt32(Value1.Text) + Convert.ToInt32(Value2.Text);
AnswerMessage.Text = Answer.ToString();
}
</script>
</head>
<body>
<form runat="server">
<h3> TextBox Example </h3>
<table>
<tr>
<td colspan="5">
Enter integer values into the text boxes. <br>
Click the Add button to add the two values. <br>
Click the Reset button to reset the text boxes.
</td>
</tr>
<tr>
<td colspan="5">
</td>
</tr>
<tr align="center">
<td>
<asp:TextBox ID="Value1"
Columns="2"
MaxLength="3"
Text="1"
runat="server"/>
</td>
<td>
+
</td>
<td>
<asp:TextBox ID="Value2"
Columns="2"
MaxLength="3"
Text="1"
runat="server"/>
</td>
<td>
=
</td>
<td>
<asp:Label ID="AnswerMessage"
runat="server"/>
</td>
</tr>
<tr>
<td colspan="2">
<asp:RequiredFieldValidator
ID="Value1RequiredValidator"
ControlToValidate="Value1"
ErrorMessage="Please enter a value.<br>"
Display="Dynamic"
runat="server"/>
<asp:RangeValidator
ID="Value1RangeValidator"
ControlToValidate="Value1"
Type="Integer"
MinimumValue="1"
MaximumValue="100"
ErrorMessage="Please enter an integer <br> between than 1 and 100.<br>"
Display="Dynamic"
runat="server"/>
</td>
<td colspan="2">
<asp:RequiredFieldValidator
ID="Value2RequiredValidator"
ControlToValidate="Value2"
ErrorMessage="Please enter a value.<br>"
Display="Dynamic"
runat="server"/>
<asp:RangeValidator
ID="Value2RangeValidator"
ControlToValidate="Value2"
Type="Integer"
MinimumValue="1"
MaximumValue="100"
ErrorMessage="Please enter an integer <br> between than 1 and 100.<br>"
Display="Dynamic"
runat="server"/>
</td>
<td>
 
</td
</tr>
<tr align="center">
<td colspan="4">
<asp:Button ID="AddButton"
Text="Add"
OnClick="AddButton_Click"
runat="server"/>
</td>
<td>
</td>
</tr>
</table>
</form>
</body>
</html>
Plattformen
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
Siehe auch
Referenz
TextBox-Klasse
TextBox-Member
System.Web.UI.WebControls-Namespace
Rows
MaxLength