Bagikan melalui

HtmlTextArea.OnPreRender(EventArgs) Metode

  • Referensi

Definisi

Ruang nama:
System.Web.UI.HtmlControls
Rakitan:
System.Web.dll

Memunculkan kejadian PreRender.

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

Objek EventArgs yang berisi data peristiwa.

Contoh

Contoh kode berikut menunjukkan cara mengganti OnPreRender metode untuk selalu menampilkan 5 baris dan 75 kolom dalam kontrol server kustom HtmlTextArea .

<%@ 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)
  {

    HtmlTextArea1.Value = "Hello Html Text Area World.";

  }
</script>

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

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

      <h3>Custom HtmlTextArea OnPreRender Example</h3>

      <aspSample:CustomHtmlTextAreaOnPreRender 
        id="HtmlTextArea1" 
        name="HtmlTextArea1" 
        runat="server" 
        rows="4" 
        cols="50" />
        
    </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(ByVal sender As Object, ByVal e As EventArgs)

    HtmlTextArea1.Value = "Hello Html Text Area World."

  End Sub
  
</script>

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

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

      <h3>Custom HtmlTextArea OnPreRender Example</h3>

      <aspSample:CustomHtmlTextAreaOnPreRender 
        id="HtmlTextArea1" 
        name="HtmlTextArea1" 
        runat="server" 
        rows="4" 
        cols="50" />
        
    </form>
  </body>
</html>

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

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomHtmlTextAreaOnPreRender : System.Web.UI.HtmlControls.HtmlTextArea
    {
        protected override void OnPreRender(System.EventArgs e)
        {
            // Call the base class's OnPreRender method.
            base.OnPreRender(e);
            
            // Always display this control with 5 rows and 75 columns.
            this.Rows = 5;
            this.Cols = 75;
        }
    }
}

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomHtmlTextAreaOnPreRender
        Inherits System.Web.UI.HtmlControls.HtmlTextArea

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

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

            ' Always display this control with 5 rows and 75 columns.
            Me.Rows = 5
            Me.Cols = 75
        End Sub
    End Class
End Namespace

Keterangan

Metode ini OnPreRender memberi tahu HtmlTextArea kontrol untuk melakukan langkah-langkah yang diperlukan sebelum menyimpan status tampilan dan merender konten.

Metode OnPreRender ini digunakan terutama oleh pengembang kontrol yang memperluas fungsionalitas HtmlTextArea kontrol.

Catatan Bagi Inheritor

Saat mengambil alih metode di kelas turunan OnPreRender(EventArgs) , pastikan untuk memanggil metode kelas OnPreRender(EventArgs) dasar sehingga HtmlTextArea kontrol terdaftar dengan benar di halaman.

Berlaku untuk

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