通过

Page.IsStartupScriptRegistered(String) 方法

  • 参考

定义

命名空间:
System.Web.UI
程序集:
System.Web.dll

注意

The recommended alternative is ClientScript.IsStartupScriptRegistered(string key). http://go.microsoft.com/fwlink/?linkid=14202

确定 Page 对象是否注册了客户端启动脚本。

public:
 bool IsStartupScriptRegistered(System::String ^ key);
public bool IsStartupScriptRegistered (string key);
[System.Obsolete("The recommended alternative is ClientScript.IsStartupScriptRegistered(string key). http://go.microsoft.com/fwlink/?linkid=14202")]
public bool IsStartupScriptRegistered (string key);
member this.IsStartupScriptRegistered : string -> bool
[<System.Obsolete("The recommended alternative is ClientScript.IsStartupScriptRegistered(string key). http://go.microsoft.com/fwlink/?linkid=14202")>]
member this.IsStartupScriptRegistered : string -> bool
Public Function IsStartupScriptRegistered (key As String) As Boolean

参数

key
String

要搜索的启动脚本的字符串关键字。

返回

Boolean

如果注册了启动脚本，则为 true；否则为 false。

属性
ObsoleteAttribute

示例

下面的代码示例演示如何 RegisterStartupScript 将该方法与 IsStartupScriptRegistered 该方法结合使用。 如果代码声明块中编写的 ECMAScript 尚未注册，则调用由确定IsStartupScriptRegisteredRegisterStartupScript。

<%@ 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)
  {
    String csname1 = "PopupScript";
    String csname2 = "ButtonClickScript";

    if (!IsClientScriptBlockRegistered(csname1))
    {
        String cstext1 = "<script type=\"text/javascript\">" +
            "alert('Hello World');</" + "script>";
        RegisterStartupScript(csname1, cstext1);
    }

    if (!IsClientScriptBlockRegistered(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>");
      RegisterClientScriptBlock(csname2, cstext2.ToString());
    }
  }
</script>
<html  >
  <head>
    <title>RegisterClientScriptBlock 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 EventArgs)
        Dim csname1 As String = "PopupScript"

        Dim csname2 As String = "ButtonClickScript"
    
        If Not IsClientScriptBlockRegistered(csname1) Then
            Dim cstext1 As String = "<script type=""text/javascript"">" & _
                "alert('Hello World');</" & "script>"
            RegisterStartupScript(csname1, cstext1)
        End If
    
        If Not IsClientScriptBlockRegistered(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>")
            RegisterClientScriptBlock(csname2, cstext2.ToString())
        End If
    End Sub
</script>
<html  >
  <head>
    <title>RegisterClientScriptBlock 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

在调用之前调用 Page.RegisterStartupScript 此方法，以避免不必要的组装客户端脚本。 如果脚本需要大量服务器资源来创建，则这一点尤其重要。

IsStartupScriptRegistered 方法已弃用。 使用 IsStartupScriptRegistered 类中的 ClientScriptManager 方法。

适用于

另请参阅