[Wap]自定义asp.net mobile control

Device Adapter概念

按照MSDN《Walkthrough: Adding Support for Devices》的指示：

我们要想自定义MMIT(Microsoft Mobile Internet Toolkit)提供的控件，那么可以改变Adapter在最后关头的渲染工作。

首先，我们要说明render的概念，最好的动画教程就是http://www.asp.net/mobile/2514A_01A001.swf，它是Mobile Web Application Architecture的flash讲解。

所有的ASP.NET mobile device adapter都是通过text writer做render的。这些text writer均继承自MobileTextWriter。它提供了Write, WriteLine, 以及WriteBeginTag等方法。对于WML来说，这个Text Writer是System.Web.UI.MobileControls.Adapters.WmlMobileTextWriter。

第一步，下载http://go.microsoft.com/fwlink/?LinkId=6350的Device Adapter Code源代码；

       第二步，编辑其中的WmlTextBoxAdapter.cs文件；

      第三步，通过csc.exe生成出一个新的Adapter DLL；

      第四步，配置web.config；

      第五步，重新编译你的工程。

      可惜呀，MobileIt.exe下载不了。当然在ASP.NET 2.0中，是很容易地自定义Adapter的。

那么现在ASP.NET 1.1中，我们只好折衷采用下面的办法：

自定义一个Adapter类

在这里我们来定义一个继承自

System.Web.UI.MobileControls.Adapters.WmlListAdapter

的Adapter，来准备改写mobile:list控件的输出方式。

将下面的代码保存为ListAdapter.cs：

编译ListAdapter

利用下面的命令编译出一个ListAdapter.dll：

csc /t:library /r:System.Web.Mobile.dll ListAdapter.cs

将这个ListAdapter.DLL复制到你的WAP应用程序bin目录下。

修改web.config来提供control mapping

在你的web.config文件中找到mobileControls节点，修改为以下：

device节点就声明了一个新的Adapter，名为“UltraListDeviceAdapters”，这个名字是可以随便定义的。inheritsFrom属性是指。你必须提供控件的fully qualified control class name：“iUltraMobiles.ListAdapter, iUltraMobiles”，control的name属性指的是“你重载的哪一个mobile控件”。

试用新控件

现在你已经修改了mobile:list控件的最终渲染方式，在它原本输出的诸多个<a> tag之前抢先输出了你的image的符合wml规范的tag。

这样，你的aspx页面不需要做任何改动，重新编译你的工程后，新的渲染方式就生效了。

你可以在M3gate模拟器上试验。

附录A   mobileControls例子：

下面给一个比较完整的例子做示范：

<!-- Adapter configuration for mobile controls used in the portal -->

附录B   mobileControls属性定义表：

      mobileControls节点的具体各项属性定义可以参见：

      http://msdn.microsoft.com/library/default.asp?url=/library/en-us/mwsdk/html/mwlrfdevice.asp

     The <mobileControls> element has the attributes shown in the following table.

static bool EvaluatorMethod(HttpContext context)

附录C 实例代码：

        '*********************************************************************
        '
        ' HtmlTabbedPanelAdapter.Render Method
        '
        ' Renders the control. The TabbedPanel is rendered as one or more
        ' rows of tabs that the user can click on to move between tabs.
        '
        '*********************************************************************

        Public Overloads Overrides Sub Render(ByVal writer As HtmlMobileTextWriter)
        
            Dim _activePane As IPanelPane = Control.ActivePane
            Dim tabsPerRow As Integer = Control.TabsPerRow
            Dim panes As PanelPaneCollection = Control.Panes
            Dim paneCount As Integer = panes.Count

            ' Figure out the number of visible panes.
            Dim visiblePanes(paneCount) As Integer
            Dim visiblePaneCount As Integer = 0
            Dim i As Integer

            For i = 0 To paneCount - 1

                If CType(panes(i), Control).Visible Then

                    visiblePanes(visiblePaneCount) = i
                    visiblePaneCount += 1

                End If

            Next i

            ' Calculate how many rows are necessary.
            Dim rows As Integer = (visiblePaneCount + tabsPerRow - 1) / tabsPerRow

            ' make sure tabsPerRow doesn't exceed the number of visible panes
            If Control.TabsPerRow > visiblePaneCount Then
                tabsPerRow = visiblePaneCount
            Else
                tabsPerRow = Control.TabsPerRow
            End If

            ' Open the table.
            writer.WriteBeginTag("table")
            writer.WriteAttribute("cellspacing", "0")
            writer.WriteAttribute("cellpadding", "2")
            writer.WriteAttribute("border", "0")
            writer.WriteLine(">")

            Dim row As Integer

            For row = rows - 1 To 0 Step -1

                writer.WriteFullBeginTag("tr")
                writer.WriteLine()

                Dim col As Integer

                For col = 0 To tabsPerRow - 1
                    writer.WriteBeginTag("td")
                    writer.WriteAttribute("width", "0")
                    writer.Write(">")
                    writer.WriteEndTag("td")

                    i = row * tabsPerRow + col
                    If row > 0 And i >= visiblePaneCount Then

                        writer.WriteFullBeginTag("td")
                        writer.WriteEndTag("td")
                        Goto ContinueNextCol

                    End If

                    Dim index As Integer = visiblePanes(i)
                    Dim child As IPanelPane = panes(index)

                    If child Is _activePane Then

                        writer.WriteBeginTag("td")
                        writer.WriteAttribute("bgcolor", GetColorString(Control.ActiveTabColor, "#333333"))
                        writer.Write(">")

                        writer.WriteBeginTag("font")
                        writer.WriteAttribute("face", "Verdana")
                        writer.WriteAttribute("size", "-2")
                        writer.WriteAttribute("color", GetColorString(Control.ActiveTabTextColor, "#000000"))
                        writer.Write(">")

                        writer.WriteFullBeginTag("b")
                        writer.Write(" ")
                        writer.WriteText(child.Title, True)
                        writer.Write(" ")
                        writer.WriteEndTag("b")

                        writer.WriteEndTag("font")

                        writer.WriteEndTag("td")
                        writer.WriteLine()
                    Else
                        writer.WriteBeginTag("td")
                        writer.WriteAttribute("bgcolor", GetColorString(Control.TabColor, "#cccccc"))
                        writer.Write(">")

                        writer.WriteBeginTag("font")
                        writer.WriteAttribute("face", "Verdana")
                        writer.WriteAttribute("size", "-2")
                        writer.WriteAttribute("color", GetColorString(Control.TabTextColor, "#000000"))
                        writer.Write(">")

                        writer.Write(" ")
                        writer.WriteBeginTag("a")
                        RenderPostBackEventAsAttribute(writer, "href", index.ToString())
                        writer.Write(">")
                        writer.WriteText(child.Title, True)
                        writer.WriteEndTag("a")
                        writer.Write(" ")

                        writer.WriteEndTag("font")

                        writer.WriteEndTag("td")
                        writer.WriteLine()
                    End If
ContinueNextCol:
                Next col
                writer.WriteEndTag("tr")
                writer.WriteLine()

                If row > 0 Then
                    writer.WriteFullBeginTag("tr")
                    writer.WriteBeginTag("td")
                    writer.WriteAttribute("height", "1")
                    writer.Write(">")
                    writer.WriteEndTag("td")
                    writer.WriteEndTag("tr")
                    writer.WriteLine()
                End If
            Next row

            writer.WriteEndTag("table")
            writer.WriteLine()

            writer.WriteBeginTag("table")
            writer.WriteAttribute("width", "100%")
            writer.WriteAttribute("height", "2")
            writer.WriteAttribute("border", "0")
            writer.WriteAttribute("cellspacing", "0")
            writer.WriteAttribute("bgcolor", "#000000")
            writer.Write(">")
            writer.WriteFullBeginTag("tr")
            writer.WriteFullBeginTag("td")
            writer.WriteEndTag("td")
            writer.WriteEndTag("tr")
            writer.WriteEndTag("table")
            writer.WriteBreak()

            CType(_activePane, Control).RenderControl(writer)

        End Sub