CODEWITHSUNDEEP
javascriptc#
Hamdi
Hamdi

Reputation: 51

JavaScript function not defined in c# code

I am working with VS, a web form application, and I want to generate in the code-behind (C#) a JavaScript function defined in a JavaScript file in the project,. I have tried different ways ,such as this line of code:

Page.ClientScript.RegisterStartupScript(this.GetType(), "CallMyFunction", "Function_Name", true);

However, it can't resolve the name of my function since it's "not defined" as it's shown as a JavaScript error. But it works fine with a simple line of JavaScript code put in the Function_Name field (like alert("something")).

Any help with this please?

Upvotes: 1

Views: 1263

Answers (1)

scopolamin
scopolamin

Reputation: 574

C#

define your javascript inside the C# code as text

Type type = this.GetType();
String key = "CallMyFunction";
ClientScriptManager cs = Page.ClientScript;

if (!cs.IsClientScriptBlockRegistered(type, key))
{
  StringBuilder script = new StringBuilder();
  script.AppendLine("<script type=\"text/javascript\">");
  script.AppendLine("  function Function_Name() {");
  script.AppendLine("    frmMain.Message.value = 'Hello World';");
  script.AppendLine("  }");
  script.AppendLine("</script>");

  cs.RegisterClientScriptBlock(type, key, script.ToString(), false);
}

or read your javascript from a .js file

<script type="text/javascript">
  function Function_Name() {
    frmMain.Message.value = 'Hello World';
  }
</script>

Type type = this.GetType();
String key = "CallMyFunction";
ClientScriptManager cs = Page.ClientScript;

if (!cs.IsClientScriptBlockRegistered(type, key) && File.Exists(path))
{
  string script = File.ReadAllText(path);

  cs.RegisterClientScriptBlock(type, key, script, false);
}

HTML - Body

<body>
  <form id="frmMain" runat="server">
    <input type="text" id="Message" />
    <input type="button" value="Click!" onclick="Function_Name()" />
  </form>
</body>

If you need a one-liner:

Page.ClientScript.RegisterStartupScript(this.GetType(), "CallMyFunction", "function Function_Name() { frmMain.Message.value='Hello World'; }", true);

or

Page.ClientScript.RegisterStartupScript(this.GetType(), "CallMyFunction", "<script type=\"text/javascript\">function Function_Name() { frmMain.Message.value='Hello World'; }</script>", false);

EDIT:

Using includes

String includeKey = "MyInclude";
String includeFile = "/myInclude.js";
String scriptKey = "CallMyFunction";
String script = "Function_Name();"; //Function inside your included js file.
Type type = GetType();
ClientScriptManager cs = Page.ClientScript;

//register the js file containing the function
if (!cs.IsClientScriptIncludeRegistered(includeKey))
{
    cs.RegisterClientScriptInclude(includeKey, includeFile);
}

//register the script to call the function 
if (!cs.IsClientScriptBlockRegistered(scriptKey))
{
    cs.RegisterClientScriptBlock(type, scriptKey, script, true);
}

Upvotes: 1

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