ClientScriptManager.IsClientScriptBlockRegistered 方法

参考

定义

命名空间:: System.Web.UI

程序集:: System.Web.dll

重要

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确定 Page 对象是否注册了客户端脚本块。

重载

IsClientScriptBlockRegistered(String)	使用指定键确定 Page 对象是否注册了客户端脚本块。
IsClientScriptBlockRegistered(Type, String)	使用键和类型确定 Page 对象是否注册了客户端脚本块。

IsClientScriptBlockRegistered(String)

使用指定键确定 Page 对象是否注册了客户端脚本块。

public:
 bool IsClientScriptBlockRegistered(System::String ^ key);

public bool IsClientScriptBlockRegistered (string key);

member this.IsClientScriptBlockRegistered : string -> bool

Public Function IsClientScriptBlockRegistered (key As String) As Boolean

参数

key: String

要搜索的客户端脚本块的键。

Boolean

如果注册了客户端脚本块，则为 true；否则为 false。

示例

<%@ Page Language="C#"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  public void Page_Load(Object sender, EventArgs e)
  {
    // Define the name and type of the client scripts on the page.
    String csname1 = "PopupScript";
    String csname2 = "ButtonClickScript";
    Type cstype = this.GetType();
        
    // Get a ClientScriptManager reference from the Page class.
    ClientScriptManager cs = Page.ClientScript;

    // Check to see if the startup script is already registered.
    if (!cs.IsStartupScriptRegistered(cstype, csname1))
    {
      String cstext1 = "alert('Hello World');";
      cs.RegisterStartupScript(cstype, csname1, cstext1);
    }

    // Check to see if the client script is already registered.
    if (!cs.IsClientScriptBlockRegistered(cstype, csname2))
    {
      StringBuilder cstext2 = new StringBuilder();
      cstext2.Append("<script type=\"text/javascript\"> function DoClick() {");
      cstext2.Append("Form1.Message.value='Text from client script.'} </");
      cstext2.Append("script>");
      cs.RegisterClientScriptBlock(cstype, csname2, cstext2.ToString());
    }
  }
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>ClientScriptManager Example</title>
  </head>
  <body>
     <form id="Form1"
         runat="server">
        <input type="text" id="Message" /> <input type="button" value="ClickMe" onclick="DoClick()" />
     </form>
  </body>
</html>

<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

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

    ' Define the name and type of the client scripts on the page.
    Dim csname1 As String = "PopupScript"
    Dim csname2 As String = "ButtonClickScript"
    Dim cstype As Type = Me.GetType()
    
    ' Get a ClientScriptManager reference from the Page class.
    Dim cs As ClientScriptManager = Page.ClientScript

    ' Check to see if the startup script is already registered.
    If (Not cs.IsStartupScriptRegistered(cstype, csname1)) Then
      
      Dim cstext1 As String = "alert('Hello World');"
            cs.RegisterStartupScript(cstype, csname1, cstext1)
      
    End If
    
    ' Check to see if the client script is already registered.
    If (Not cs.IsClientScriptBlockRegistered(cstype, csname2)) Then
      
      Dim cstext2 As New StringBuilder()
            cstext2.Append("<script type=""text/javascript""> function DoClick() {")
      cstext2.Append("Form1.Message.value='Text from client script.'} </")
      cstext2.Append("script>")
            cs.RegisterClientScriptBlock(cstype, csname2, cstext2.ToString())
      
    End If
    
  End Sub
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>ClientScriptManager Example</title>
  </head>
  <body>
     <form id="Form1"
         runat="server">
        <input type="text" id="Message" /> <input type="button" value="ClickMe" onclick="DoClick()" />
     </form>
  </body>
</html>

注解

在调用该方法之前调用 RegisterClientScriptBlock 此方法以避免注册重复的脚本。如果脚本需要大量服务器资源才能创建，这一点尤其重要。

客户端脚本由其密钥及其类型唯一标识。具有相同键和类型的脚本被视为重复项。

此方法的IsClientScriptBlockRegistered此重载调用重载，该重载采用key类型集为Page对象的重载和type参数

另请参阅

适用于

IsClientScriptBlockRegistered(Type, String)

使用键和类型确定 Page 对象是否注册了客户端脚本块。

public:
 bool IsClientScriptBlockRegistered(Type ^ type, System::String ^ key);

public bool IsClientScriptBlockRegistered (Type type, string key);

member this.IsClientScriptBlockRegistered : Type * string -> bool

Public Function IsClientScriptBlockRegistered (type As Type, key As String) As Boolean

参数

type: Type

要搜索的客户端脚本块的类型。

key: String

要搜索的客户端脚本块的键。

Boolean

如果注册了客户端脚本块，则为 true；否则为 false。

例外

ArgumentNullException

客户端脚本类型为 null。

示例

下面的代码示例演示了该方法 IsClientScriptBlockRegistered 的使用。请注意，如果删除了检查现有客户端脚本块的逻辑，则呈现页面的 HTML 源代码中不会有两个重复的客户端脚本，因为 RegisterClientScriptBlock 该方法会检查重复项。检查的好处是减少不必要的计算。

<%@ Page Language="C#"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  public void Page_Load(Object sender, EventArgs e)
  {
    // Define the name and type of the client scripts on the page.
    String csname1 = "PopupScript";
    String csname2 = "ButtonClickScript";
    Type cstype = this.GetType();
        
    // Get a ClientScriptManager reference from the Page class.
    ClientScriptManager cs = Page.ClientScript;

    // Check to see if the startup script is already registered.
    if (!cs.IsStartupScriptRegistered(cstype, csname1))
    {
      String cstext1 = "alert('Hello World');";
      cs.RegisterStartupScript(cstype, csname1, cstext1, true);
    }

    // Check to see if the client script is already registered.
    if (!cs.IsClientScriptBlockRegistered(cstype, csname2))
    {
      StringBuilder cstext2 = new StringBuilder();
      cstext2.Append("<script type=\"text/javascript\"> function DoClick() {");
      cstext2.Append("Form1.Message.value='Text from client script.'} </");
      cstext2.Append("script>");
      cs.RegisterClientScriptBlock(cstype, csname2, cstext2.ToString(), false);
    }
  }
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>ClientScriptManager Example</title>
  </head>
  <body>
     <form id="Form1"
         runat="server">
        <input type="text" id="Message" /> <input type="button" value="ClickMe" onclick="DoClick()" />
     </form>
  </body>
</html>

<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

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

    ' Define the name and type of the client scripts on the page.
    Dim csname1 As String = "PopupScript"
    Dim csname2 As String = "ButtonClickScript"
    Dim cstype As Type = Me.GetType()
    
    ' Get a ClientScriptManager reference from the Page class.
    Dim cs As ClientScriptManager = Page.ClientScript

    ' Check to see if the startup script is already registered.
    If (Not cs.IsStartupScriptRegistered(cstype, csname1)) Then
      
      Dim cstext1 As String = "alert('Hello World');"
      cs.RegisterStartupScript(cstype, csname1, cstext1, True)
      
    End If
    
    ' Check to see if the client script is already registered.
    If (Not cs.IsClientScriptBlockRegistered(cstype, csname2)) Then
      
      Dim cstext2 As New StringBuilder()
            cstext2.Append("<script type=""text/javascript""> function DoClick() {")
      cstext2.Append("Form1.Message.value='Text from client script.'} </")
      cstext2.Append("script>")
      cs.RegisterClientScriptBlock(cstype, csname2, cstext2.ToString(), False)
      
    End If
    
  End Sub
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>ClientScriptManager Example</title>
  </head>
  <body>
     <form id="Form1"
         runat="server">
        <input type="text" id="Message" /> <input type="button" value="ClickMe" onclick="DoClick()" />
     </form>
  </body>
</html>

注解

在调用该方法之前调用 RegisterClientScriptBlock 此方法以避免注册重复的脚本。如果脚本需要大量服务器资源才能创建，这一点尤其重要。

客户端脚本由其密钥及其类型唯一标识。具有相同键和类型的脚本被视为重复项。根据将访问资源的对象指定类型。例如，使用 Page 实例访问资源时，请指定 Page 类型。

另请参阅

适用于

通过

ClientScriptManager.IsClientScriptBlockRegistered 方法

定义

重载

IsClientScriptBlockRegistered(String)

参数

返回

示例

注解

另请参阅

适用于

IsClientScriptBlockRegistered(Type, String)

参数

返回

例外

示例

注解

另请参阅

适用于

其他资源