HttpUtility クラスとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

索引トップ用語の索引ランキング

HttpUtility クラス

Web 要求の処理時に URL をエンコードおよびデコードするためのメソッドを提供します。このクラスは継承できません。

名前空間: System.Web
アセンブリ: System.Web (system.web.dll 内)
構文

Visual Basic (宣言)

Public NotInheritable Class
 HttpUtility

Visual Basic (使用法)

Dim instance As HttpUtility

public sealed class HttpUtility

C++

public ref class HttpUtility sealed

public final class HttpUtility

JScript

public final class HttpUtility

解説

HttpUtility クラスは、HttpServerUtility クラスによって内部的に使用されます。このクラスのメソッドとプロパティは、組み込みの ASP.NET Server オブジェクトを通じて公開されます。また、HttpUtility クラスには、Server からはアクセスできないエンコードとデコードを行うためのユーティリティメソッドが含まれています。

使用例

HttpUtility クラスの HtmlEncode、HtmlDecode、ParseQueryString の各メソッドの使用方法を次のコード例に示します。

Visual Basic

<%@ Page Language="VB" %>

<script runat="server">

  Protected Sub Page_Load(ByVal
 sender As Object, ByVal
 e As System.EventArgs)

    Dim currurl As String
 = HttpContext.Current.Request.RawUrl
    Dim querystring As String
 = Nothing
    
    ' Check to make sure some query string variables
    ' exist and if not add some and redirect.
    Dim iqs As Int32 = currurl.IndexOf("?".ToCharArray())
    If (iqs = -1) Then
      
      Dim redirecturl As String
 = currurl & "?var1=1&var2=2+2%2f3&var1=3"
      Response.Redirect(redirecturl, True)
      
      ' If query string variables exist, put them in
      ' a string.
    ElseIf (iqs >= 0) Then
      
      If (iqs < currurl.Length - 1) Then
        querystring = currurl.Substring(iqs + 1)
      End If
          
    End If

    ' Parse the query string variables into a NameValueCollection.
    Dim qscoll As NameValueCollection = HttpUtility.ParseQueryString(querystring)
    
    ' Iterate through the collection.
    Dim sb As New StringBuilder()
    For Each s As String
 In qscoll.AllKeys
      
      sb.Append(s & " - " & qscoll(s) &
 "<br>")
    
    Next s
    
    ' Write the results to the appropriate labels.
    ParseOutput.Text = sb.ToString()
    UrlRawOutput.Text = currurl
    UrlEncodedOutput.Text = HttpUtility.UrlEncode(currurl)
    UrlDecodedOutput.Text = HttpUtility.UrlDecode(currurl)
   
  End Sub
  
</script>

<html>
<head id="Head1" runat="server">
    <title>HttpUtility ParseQueryString Example</title>
</head>
<body>
    <form id="Form1" runat="server">
      The raw url is: <br />
      <asp:Label  id="UrlRawOutput"
                  runat="server" />
      <br /><br />
      The url encoded is: <br />
      <asp:Label  id="UrlEncodedOutput"
                  runat="server" />
      <br /><br />
      The url decoded is: <br />
      <asp:Label  id="UrlDecodedOutput"
                  runat="server" />
      <br /><br />
      The query string NameValueCollection is:
 <br />
      <asp:Label  id="ParseOutput"
                  runat="server" />
    </form>
</body>
</html>

<%@ Page Language="C#"%>

<script runat="server">

  protected void Page_Load(object sender, EventArgs
 e)
  {
    String currurl = HttpContext.Current.Request.RawUrl;
    String querystring = null ;

    // Check to make sure some query string variables
    // exist and if not add some and redirect.
    int iqs = currurl.IndexOf('?');
    if (iqs == -1)
    {
      String redirecturl = currurl + "?var1=1&var2=2+2%2f3&var1=3";
      Response.Redirect(redirecturl, true); 
    }
    // If query string variables exist, put them in
    // a string.
    else if (iqs >= 0)
    {
      querystring = (iqs < currurl.Length - 1) ? currurl.Substring(iqs + 1) :
 String.Empty;
    }
   
    // Parse the query string variables into a NameValueCollection.
    NameValueCollection qscoll = HttpUtility.ParseQueryString(querystring);
    
    // Iterate through the collection.
    StringBuilder sb = new StringBuilder();
    foreach (String s in qscoll.AllKeys)
    {
      sb.Append(s + " - " + qscoll[s] + "<br>");
    }
    
    // Write the results to the appropriate labels.
    ParseOutput.Text = sb.ToString();
    UrlRawOutput.Text = currurl;
    UrlEncodedOutput.Text = HttpUtility.UrlEncode(currurl);
    UrlDecodedOutput.Text = HttpUtility.UrlDecode(currurl);
  }
</script>

<html>
<head runat="server">
    <title>HttpUtility ParseQueryString Example</title>
</head>
<body>
    <form runat="server">
      The raw url is: <br />
      <asp:Label  id="UrlRawOutput"
                  runat="server" />
      <br /><br />
      The url encoded is: <br />
      <asp:Label  id="UrlEncodedOutput"
                  runat="server" />
      <br /><br />
      The url decoded is: <br />
      <asp:Label  id="UrlDecodedOutput"
                  runat="server" />
      <br /><br />
      The query string NameValueCollection is: <br />
      <asp:Label  id="ParseOutput"
                  runat="server" />
    </form>
</body>
</html>