ExtAspNet应用技巧（二）

ExtAspNet应用技巧（二）

在ExtAspNet应用中，如何获取FCKEditor的值以及如何设置FCKEditor的值？

首先把例子的截图放上来：
点击“设置FCKEditor的值”后的界面效果：

点击获取FCKEditor的值后的效果：

示例的Asp.Net代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="fckeditor_run.aspx.cs"
    ValidateRequest="false" Inherits="ExtAspNet.Examples.aspnet.fckeditor_run" %>

<%@ Register Assembly="FredCK.FCKeditorV2" Namespace="FredCK.FCKeditorV2" TagPrefix="FCKeditorV2" %>
<!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></title>
</head>
<body>
    <form id="form1" runat="server">
    <ext:PageManager ID="PageManager1" runat="server" />
    <ext:ContentPanel ID="ContentPanel1" runat="server" BodyPadding="5px" EnableBackgroundColor="true"
        ShowBorder="true" ShowHeader="true" Title="ContentPanel">

        <FCKeditorV2:FCKeditor ID="FCKeditor1" BasePath="../fckeditor/"  runat="server">
        </FCKeditorV2:FCKeditor>

    </ext:ContentPanel>
    <ext:Button ID="Button1" runat="server" Text="获取FCKEditor的值" OnClick="Button1_Click">
    </ext:Button>
    <br />
    <ext:Button ID="Button2" runat="server" Text="设置FCKEditor的值" OnClick="Button2_Click">
    </ext:Button>
    </form>
</body>
</html>

后台代码：
protected void Button1_Click(object sender, EventArgs e)
{
    Alert.Show(FCKeditor1.Value);
}

protected void Button2_Click(object sender, EventArgs e)
{
    FCKeditor1.Value = "哈哈，不错哦<strong>这是黑体</strong>";

    PageManager1.AddAjaxUpdateControl(FCKeditor1);
}

你可以从　http://extaspnet.codeplex.com/SourceControl/ListDownloadableCommits.aspx 下载最新的源代码，
示例页面在 trunk\ExtAspNet.Examples\aspnet\fckeditor_run.aspx

=====================================================================
以下内容属于高级部分，涉及部分内部实现机制。
为了达到以上目的，我们对FredCK.FCKeditorV2中的FCKeditor.cs进行了修改，原来的代码：
protected override void OnPreRender( EventArgs e )
{
    base.OnPreRender( e );

    _IsCompatible = this.CheckBrowserCompatibility();

    if ( !_IsCompatible )
        return;

    object oScriptManager = null;

    // Search for the ScriptManager control in the page.
    Control oParent = this.Parent;
    while ( oParent != null )
    {
        foreach ( object control in oParent.Controls )
        {
            // Match by type name.
            if ( control.GetType().FullName == "System.Web.UI.ScriptManager" )
            {
                oScriptManager = control;
                break;
            }
        }

        if ( oScriptManager != null )
            break;

        oParent = oParent.Parent;
    }

    // If the ScriptManager control is available.
    if ( oScriptManager != null )
    {
        try
        {
            // Use reflection to check the SupportsPartialRendering
            // property value.
            bool bSupportsPartialRendering = ((bool)(oScriptManager.GetType().GetProperty( "SupportsPartialRendering" ).GetValue( oScriptManager, null )));

            if ( bSupportsPartialRendering )
            {
                string sScript = "(function()\n{\n" +
                    "\tvar editor = FCKeditorAPI.GetInstance('" + this.ClientID + "');\n" +
                    "\tif (editor)\n" +
                    "\t\teditor.UpdateLinkedField();\n" +
                    "})();\n";

                // Call the RegisterOnSubmitStatement method through
                // reflection.
                oScriptManager.GetType().GetMethod( "RegisterOnSubmitStatement", new Type[] { typeof( Control ), typeof( Type ), typeof( String ), typeof( String ) } ).Invoke( oScriptManager, new object[] {
                    this,
                    this.GetType(),
                    "FCKeditorAjaxOnSubmit_" + this.ClientID,
                    sScript } );

                // Tell the editor that we are handling the submit.
                this.Config[ "PreventSubmitHandler" ] = "true";
            }
        }
        catch { }
    }
}

可以看到其中有支持Asp.Net AJAX的代码，大概的意思是：
如果页面中启用了Asp.Net AJAX，也就是存在 System.Web.UI.ScriptManager 控件，并且的控件的属性SupportsPartialRendering为true.
此时调用此控件的RegisterOnSubmitStatement方法注册一段脚本 sScript ，在提交表单之前更新FCKEditor隐藏的input的值，只有这样才能
讲FCKEditor的值传递到服务器处理程序。
我们看下页面中生成的HTML代码就更清楚了：
<div>
<input type="hidden" id="ContentPanel1_FCKeditor1" name="ContentPanel1$FCKeditor1" value="" />
<input type="hidden" id="ContentPanel1_FCKeditor1___Config" value="PreventSubmitHandler=true&HtmlEncodeOutput=true" />
<iframe id="ContentPanel1_FCKeditor1___Frame" src="../fckeditor/editor/fckeditor.html?InstanceName=ContentPanel1_FCKeditor1&Toolbar=Default" width="100%" height="200px" frameborder="no" scrolling="no"></iframe>
</div>

然后我们就照葫芦画瓢，也提供对ExtAspNet AJAX的支持，如下所示：
protected override void OnPreRender(EventArgs e)
{
    base.OnPreRender(e);

    _IsCompatible = this.CheckBrowserCompatibility();

    if (!_IsCompatible)
        return;

    object oScriptManager = GetPageControl("System.Web.UI.ScriptManager");

    // If the ScriptManager control is available.
    if (oScriptManager != null)
    {
        try
        {
            // Use reflection to check the SupportsPartialRendering
            // property value.
            bool bSupportsPartialRendering = ((bool)(oScriptManager.GetType().GetProperty("SupportsPartialRendering").GetValue(oScriptManager, null)));

            if (bSupportsPartialRendering)
            {
                string sScript = "(function()\n{\n" +
                    "\tvar editor = FCKeditorAPI.GetInstance('" + this.ClientID + "');\n" +
                    "\tif (editor)\n" +
                    "\t\teditor.UpdateLinkedField();\n" +
                    "})();\n";

                // Call the RegisterOnSubmitStatement method through
                // reflection.
                oScriptManager.GetType().GetMethod("RegisterOnSubmitStatement", new Type[] { typeof(Control), typeof(Type), typeof(String), typeof(String) }).Invoke(oScriptManager, new object[] {
                    this,
                    this.GetType(),
                    "FCKeditorAjaxOnSubmit_" + this.ClientID,
                    sScript });

                // Tell the editor that we are handling the submit.
                this.Config["PreventSubmitHandler"] = "true";
            }
        }
        catch { }
    }

    object extPageManager = GetPageControl("ExtAspNet.PageManager");
    if (extPageManager != null)
    {
        try
        {
            bool enableAjax = ((bool)(extPageManager.GetType().GetProperty("EnableAjax").GetValue(extPageManager, null)));

            if (enableAjax)
            {
                string sScript = "(function()\n{\n" +
                    "\tvar editor = FCKeditorAPI.GetInstance('" + this.ClientID + "');\n" +
                    "\tif (editor)\n" +
                    "\t\teditor.UpdateLinkedField();\n" +
                    "})();\n";

                extPageManager.GetType().GetMethod("RegisterOnAjaxPostBack", new Type[] { typeof(String), typeof(String) }).Invoke(extPageManager, new object[] {
                    "FCKeditorAjaxOnSubmit_" + this.ClientID,
                    sScript });

                // Tell the editor that we are handling the submit.
                this.Config["PreventSubmitHandler"] = "true";
            }
        }
        catch { }
    }
}

private object GetPageControl(string fullName)
{
    object oScriptManager = null;

    // Search for the ScriptManager control in the page.
    Control oParent = this.Parent;
    while (oParent != null)
    {
        foreach (object control in oParent.Controls)
        {
            // Match by type name.
            if (control.GetType().FullName == fullName)
            {
                oScriptManager = control;
                break;
            }
        }

        if (oScriptManager != null)
            break;

        oParent = oParent.Parent;
    }
    return oScriptManager;
}

还有我们还对Render函数进行了修正（为了使用PageManager1.AddAjaxUpdateControl(FCKeditor1);），
具体就不讲解了，有兴趣的话可以看下源代码。
happy coding.
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原文地址：https://www.cnblogs.com/sanshi/p/1528219.html