Validate fields with OnClientClick

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Validate fields with OnClientClick

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#1 by (2 votes)

1

I'm trying to call a JavaScript function through OnClientClick .

The problem is that when running in the browser it does not validate the fields, it is as if the function was simply not called.

JavaScript:

function VerificaCampos() {
   //verifica processo    
   var ddlprocesso = document.getElementById("<%=ddlProcesso.ClientID%>")
   if (ddlempresa.options[ddlprocesso.selectedIndex].value == ""){
      alert("Favor preencher processo!");
      ddlprocesso.focus();
      return false;

Button:

<asp:Button ID="btnBuscar" runat="server" CssClass="botao" 
  Text="Gerar" OnClientClick="if(VerificaCampos()) return false;" 
  OnClick="btnBuscar_Click"/>

javascript c# asp.net

asked by anonymous 18.04.2018 / 14:56

1 answer

GET FORM DATA JS [closed] How do logical operators work in PHP and how to add a GET and POST method differing?

score 2 · Accepted Answer

One of the problems is that in your javascript you are instantiating the ddlProcesso and after and after checking another object that has not been declared ddlEmpresa

function VerificaCampos() {
   //verifica processo    
   var ddlprocesso = document.getElementById("<%=ddlProcesso.ClientID%>")
   //if (ddlempresa.options[ddlprocesso.selectedIndex].value == ""){
   if (ddlprocesso.options[ddlprocesso.selectedIndex].value == ""){
      alert("Favor preencher processo!");
      ddlprocesso.focus();
      return false;
    }
}

Then as your colleague commented, if your javascript is in a js file separate from aspx, Response.Write() will not work, but you can work around this in a simple way. Just put in your dropdown the ClientIDMode="Static" attribute so your id in the DOM will be "ddlProcesso" too

<asp:DropDownList ID="ddlProcesso" runat="server" ClientIDMode="Static"></asp:DropDownList>

And in javascript you can select it without the help of ASP.Net

var ddlprocesso = document.getElementById("ddlProcesso");

And finally, change the event of your button to OnClientClick="return VerificaCampos();"

<asp:Button ID="btnBuscar" runat="server" CssClass="botao" 
  Text="Gerar" OnClientClick="return VerificaCampos();" OnClick="btnBuscar_Click"/>