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ASP.NET中的XML表单控件

 2001-03-26 10:18:10 来源:WEB开发网   
核心提示:导 读:介绍了有关asp.net中xml控件的使用,有个小BUG:在WEBFORM.ASPX中出现的XML控件,其中的transformsource属性设定了样式表文件路径,可是在文章出处没有找到这个XSL文件.:( 自己解决吧. 在这个代码中揭示了微软在ASP.NET架构中隐藏的一个WEB表单控件,即<asp:
导 读:介绍了有关asp.net中xml控件的使用,有个小BUG:在WEBFORM.ASPX中出现的XML控件,其中的transformsource属性设定了样式表文件路径,可是在文章出处没有找到这个XSL文件.:( 自己解决吧.
在这个代码中揭示了微软在ASP.NET架构中隐藏的一个WEB表单控件,即<asp:xml runat=server/>,我只给代码,不给解释,大家自己下课后去研究吧。
另外,由于是beta1,在这个控件中你使用的xslt里面不能使用<xsl:sort>,当然,亦不能使用那个order-by了,因为它支持的xsl空间是带"1999"的那个,而不是原来的那个。
另外,我从微软得到的回答就是在beta2里面,它将支持<xsl:sort>,就可以全部转向xml+xsl了,而不用再为源代码保密问题头疼了。
请看下例:
webform2.cs
                -
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.sessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Text;
using System.IO;
using System.Xml;

public class WebForm2 : Page
{
  public StringBuilder outputQ;
  public StringBuilder outputXml;
   public DocumentNavigator nav = null;
  public HtmlInputFile XmlFile;
  
  public System.Web.UI.WebControls.Xml MyXml;

  public System.Web.UI.WebControls.TextBox TextBox1;    
  public System.Web.UI.WebControls.TextBox TextBox2;
  public System.Web.UI.WebControls.TextBox TextBox3;    
  public System.Web.UI.WebControls.Button Query;
  public System.Web.UI.WebControls.Label FileLabel;
 
  public void On_KeyUp(object sender, System.EventArgs e)
  {
    Response.Write("Works");
  }

  PRotected void Page_Load(object sender, EventArgs e)
  {
    if (!IsPostBack)
    {
      //
      // Evals true first time browser hits the page
      //
    }
  }

  public void Query_Click(object sender, System.EventArgs e)
  {
    HttpPostedFile xmlfile = XmlFile.PostedFile;
     XmlDocument doc = new XmlDocument();  
     MyXml.Document = new XmlDocument();  
//    TextBox2.Text="";
//    TextBox3.Text="";

    if (xmlfile.FileName != String.Empty)
    {
      try
      {
        FileLabel.Text= xmlfile.FileName;

        MyXml.Document.Load(xmlfile.FileName);
        outputXml = new StringBuilder();
        XmlTextReader reader = new XmlTextReader (xmlfile.FileName);
        ShowDocument();
        TextBox3.Text = outputXml.ToString();

        outputQ = new StringBuilder();
        doc.Load(xmlfile.FileName);
        DocumentNavigator nav = new DocumentNavigator(doc);
        // Perform the query e.g. "descendant::book/price"
        XPathQuery(nav, TextBox1.Text);
        TextBox2.Text = outputQ.ToString();

      }
      catch (Exception exp) {
        //outputQ.Append("</xmp><font color=\"#FF6600\">"+ exp.Message+"</font><xmp>");
      }
      finally {}
    }
    else if (FileLabel.Text != String.Empty)
    {
      try
      {
        MyXml.Document.Load(FileLabel.Text);
        outputXml = new StringBuilder();
        XmlTextReader reader = new XmlTextReader (FileLabel.Text);
        ShowDocument();
        TextBox3.Text = outputXml.ToString();

        ShowDocument();

        outputQ = new StringBuilder();
        doc.Load(FileLabel.Text);
        DocumentNavigator nav = new DocumentNavigator(doc);
        // Perform the query e.g. "descendant::book/price"
        XPathQuery(nav, TextBox1.Text);
        TextBox2.Text = outputQ.ToString();

      }
      catch (Exception exp) {
        outputQ.Append("</xmp><font color=\"#FF6600\">"+ exp.Message+"</font><xmp>");
      }
      finally {}
    }
  }

  private void XPathQuery(XmlNavigator navigator, String xpathexpr )
  {
    try
    {
      // Save context node position
      navigator.PushPosition();
      navigator.Select (xpathexpr);
      FormatXml(navigator);

      // Restore context node position
      navigator.PopPosition();    
    }
    catch (Exception e)
    {
    }
  }
  
//***************************** Navigator ************************************
  private void FormatXml (XmlNavigator navigator)
  {
    while (navigator.MoveToNextSelected())
    {
      switch (navigator.NodeType)
      {
      case XmlNodeType.ProcessingInstruction:
        Format (navigator, "ProcessingInstruction");
        break;
      case XmlNodeType.DocumentType:
        Format (navigator, "DocumentType");
        break;
      case XmlNodeType.Document:
        Format (navigator, "Document");
        break;
      case XmlNodeType.Comment:
        Format (navigator, "Comment");
        break;
      case XmlNodeType.Element:
        Format (navigator, "Element");
        break;
      case XmlNodeType.Text:
        Format (navigator, "Text");
        break;
      case XmlNodeType.Whitespace:
        Format (navigator, "Whitespace");
        break;
      }
    }
    outputQ.Append("\r\n");
  }

  // Format the output
  private void Format (XmlNavigator navigator, String NodeType)
  {
    String value = String.Empty;
    String name = String.Empty;

    if (navigator.HasChildren)
    {
      name = navigator.Name;
      navigator.MoveToFirstChild();
      if (navigator.HasValue)
      {
        value = navigator.Value;
      }
    }
    else
    {
      if (navigator.HasValue)
      {
        value = navigator.Value;
        name = navigator.Name;
      }
    }
    outputQ.Append(NodeType + "<" + name + ">" + value);
    outputQ.Append("\r\n");
  }

// ********************************** XmlReader *****************************
  public void ShowDocument ()
  {
    outputXml = new StringBuilder();
    XmlTextReader reader = new XmlTextReader (FileLabel.Text);

    while (reader.Read())
    {
      switch (reader.NodeType)
      {
      case XmlNodeType.ProcessingInstruction:
        Format (reader, "ProcessingInstruction");
        break;
      case XmlNodeType.DocumentType:
        Format (reader, "DocumentType");
        break;
      case XmlNodeType.Comment:
        Format (reader, "Comment");
        break;
      case XmlNodeType.Element:
        Format (reader, "Element");
        break;
      case XmlNodeType.Text:
        Format (reader, "Text");
        break;
      case XmlNodeType.Whitespace:
        break;
      }
    }
    TextBox3.Text = outputXml.ToString();
  }

  protected void Format(XmlReader reader, String NodeType)
  {
    // Format the output
    for (int i=0; i < reader.Depth; i++)
    {
      outputXml.Append('\t');
    }

    outputXml.Append(reader.Prefix + NodeType + "<" + reader.Name + ">" + reader.Value);

    // Display the attributes values for the current node
    if (reader.HasAttributes)
    {
      outputXml.Append(" Attributes:");

      for (int j=0; j < reader.AttributeCount; j++)
      {
        outputXml.Append(reader[j]);
      }
    }
    outputXml.Append("\r\n");
  }

  /// ************************* DOM *********************************
  protected void ShowDocument(XmlNode node)
  {
    if (node != null)
      Format (node);

    if (node.HasChildNodes)
    {
      node = node.FirstChild;
      while (node != null)
      {
        ShowDocument(node);
        node = node.NextSibling;
      }
    }
  }

  // Format the output
  private void Format (XmlNode node)
  {
    if (!node.HasChildNodes)
    {
      outputXml.Append("\t" + "<" + node.Value + ">");
    }

    else
    {
      outputXml.Append("<" + node.Name + ">");
      if (XmlNodeType.Element == node.NodeType)
      {
        XmlNamedNodeMap map = node.Attributes;
        foreach (XmlNode attrnode in map)
          outputXml.Append(" " + attrnode.Name + "<" + attrnode.Value + "> ");
      }
      outputXml.Append("\r\n");
    }
  }
}


下面就是webform2.aspx了
webform2.aspx
                ---
<%@ Import Namespace="System" %>
<%@ Import Namespace="System.IO" %>
<%@ Assembly Name="System.Xml" %>
<%@ Import Namespace="System.Xml" %>
<%@ Page Language="C#" Inherits="WebForm2" Src="WebForm2.cs" Debug="true" %>

<HTML><HEAD>

 <script runat="server" language="C#">
  // Put page script here
    public void On_KeyUp(object sender, System.EventArgs e)
  {
    Response.Write("Works");
  }

 </script>

<!--<link REL="STYLESHEET" HREF="default.CSS" TYPE="text/css">-->
<TITLE>test</TITLE>
</HEAD>

<BODY  >

  
<form method="post" action="WebForm2.aspx" runat="server" enctype="multipart/form-data">
 
<div align="left">
<table>
 <tr>
  <td>XML Document:</td>
  <td><input type=file id="XmlFile" runat=server>     FileName:</td>
  <td><asp:label id="FileLabel" runat="server"></asp:label></td>
 </tr>

 <tr>
  <td>XPath Expression</td>
  <td><asp:textbox id=TextBox1 runat="server" Height="20" Width="300" text=".//text()"
OnKey_Up="On_KeyUp"></asp:textbox></td>
  <td><asp:button type=submit OnClick="Query_Click" runat="server" Height="20" Width="91"
text="Query"></asp:button></td>
 </tr>
</table>

</br>
<table>
 <tr><td>Output from Query</td><td>XML Data</td><tr>
 <tr><td>Query Display: <asp:dropdownlist runat="server">
             <asp:listitem>Descriptive</asp:listitem>
             <asp:listitem>XML</asp:listitem>
             </asp:dropdownlist>
 </td><tr>
 <tr>
  <td width="50%" valign="top" align="left"><asp:textbox id=TextBox2 runat="server" Height="400"
Width="350" TextMode="MultiLine" Rows="10"></asp:textbox></td>
  <td width="50%" valign="top" align="left"><asp:xml id="MyXml" transformsource="test.xsl"
runat=server/></asp:xml></td>
 </tr>
</table>
</div>

  <td><asp:textbox id=TextBox3 runat="server" Height="1" Width="5" TextMode="MultiLine"
Rows="110"></asp:textbox></td>

</form>
  
</BODY>
</HTML>

Tags:ASP NET XML

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