HtmlInputText.OnPreRender(EventArgs) Methode

Referenz

Definition

Namespace:: System.Web.UI.HtmlControls

Assembly:: System.Web.dll

Wichtig

Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.

Löst das PreRender-Ereignis aus.

protected:
 override void OnPreRender(EventArgs ^ e);

protected public:
 override void OnPreRender(EventArgs ^ e);

protected override void OnPreRender (EventArgs e);

protected internal override void OnPreRender (EventArgs e);

override this.OnPreRender : EventArgs -> unit

Protected Overrides Sub OnPreRender (e As EventArgs)

Protected Friend Overrides Sub OnPreRender (e As EventArgs)

Parameter

e: EventArgs

Ein EventArgs, das die Ereignisdaten enthält.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie die OnPreRender -Methode überschrieben wird, sodass die MaxLength -Eigenschaft in einem benutzerdefinierten HtmlInputText Serversteuerelement auf 30 Zeichen festgelegt wird.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" AutoEventWireup="True" %>

<!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(Object sender, EventArgs e) 
  {
    if (!Page.IsPostBack)
    {
      HtmlInputText1.Value = "Hello HtmlInputText World.";
    }
  }

  void HtmlInputText1_ServerChange(object sender, System.EventArgs e)
  {

    // Diplay the value of the selected HtmlInputText control.
    System.Web.UI.HtmlControls.HtmlInputText htmlInputText1 = (System.Web.UI.HtmlControls.HtmlInputText) sender;
    Div1.InnerHtml = "Change the preceding text to:<br />" + htmlInputText1.Value;

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>Custom HtmlInputText OnPreRender Example</title>
  </head>

  <body>
    
    <form id="Form1" method="post" runat="server">

      <h3>Custom HtmlInputText OnPreRender Example</h3>

      <p>Make a change to the text, and then press the ENTER.<br />

      <aspSample:CustomHtmlInputTextOnPreRender 
        id="HtmlInputText1" 
        name="HtmlInputText1" 
        runat="server" 
        type="text"
        size="45"
        style="WIDTH: 305px; HEIGHT: 22px" 
        onserverchange="HtmlInputText1_ServerChange">

      </p>
      <br />
      <div 
        id="Div1" 
        runat="server" 
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
          
    </form>
  </body>
</html>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" AutoEventWireup="True" %>

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

  Sub Page_Load(sender As Object, e As EventArgs)

    If Not Page.IsPostBack Then

      HtmlInputText1.Value = "Hello HtmlInputText World."

    End If

  End Sub

  Sub HtmlInputText1_ServerChange(sender As Object, e As System.EventArgs)

    Dim htmlInputText1 As System.Web.UI.HtmlControls.HtmlInputText = CType(sender, System.Web.UI.HtmlControls.HtmlInputText)
    Div1.InnerHtml = "Change the preceding text to:<br />" & htmlInputText1.Value

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>Custom HtmlInputText OnPreRender Example</title>
  </head>

  <body>
    <form id="Form1" method="post" runat="server">

      <h3>Custom HtmlInputText OnPreRender Example</h3>

      <p>Make a change to the text, and then press the ENTER.<br />

      <aspSample:CustomHtmlInputTextOnPreRender 
        id="HtmlInputText1" 
        name="HtmlInputText1" 
        runat="server" 
        type="text"
        size="45"
        style="WIDTH: 305px; HEIGHT: 22px" 
        onserverchange="HtmlInputText1_ServerChange">

      </p>
      <br />
      <div 
        id="Div1" 
        runat="server" 
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
          
    </form>
  </body>
</html>

using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomHtmlInputTextOnPreRender : System.Web.UI.HtmlControls.HtmlInputText
    {
        protected override void OnPreRender(System.EventArgs e)
        {
            // Call the base class's OnPreRender method.
            base.OnPreRender(e);

            // Set the HtmlInputText object's MaxLength property to 30 characters.
            this.MaxLength = 30;
        }
    }
}

<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomHtmlInputTextOnPreRender
    Inherits System.Web.UI.HtmlControls.HtmlInputText

    Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)

        ' Call the base class's OnPreRender method.
        MyBase.OnPreRender(e)

        ' Set the HtmlInputText object's MaxLength property to 30 characters.
        Me.MaxLength = 30
    End Sub
End Class

Hinweise

Die OnPreRender -Methode wird kurz vor dem Rendern des Steuerelements HtmlInputText aufgerufen. Die OnPreRender -Methode wird in erster Linie von Steuerelemententwicklern verwendet, die die Funktionalität des Steuerelements HtmlInputText erweitern.

Gilt für:

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