Is SearchString acting like a property? - asp.net

Is SearchString acting as property of Page class?
Here is code,
<%# 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 string SearchString
{
get { return txtSearch.Text; }
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Button Search Typed</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label
id="lblSearch"
Text="Search:"
Runat="server" />
<asp:TextBox
id="txtSearch"
Runat="server" />
<asp:Button
id="btnSearch"
Text="Go!"
PostBackUrl="ButtonSearchResultsTyped.aspx"
Runat="server" />
</div>
</form>
</body>
</html>

It is a property of your page class. This is not the page class. Your class inherits from the main page class.
Also, you need to be careful how you use thist kind of thing. Remember, ASP.Net pages are stateless, just like with other platforms. That means every time you do a postback, including just to handle simple server events like button clicks, you are working with a new instance of the class. Any previous SearchString value was lost.

It's a property of the class generated for your ASPX file, which inherits from System.Web.UI.Page. It's not added to that class itself, of course.

Related

Compiler Error Message: CS0103: The name 'Test1' does not exist in the current context

I am completely new to programming in ASP.NET and do not understand why the error "Compiler Error Message: CS0103: The name 'Test1' does not exist in the current context" occurs on this basic piece of code.
Below is the code that I am trying to compile -
<%# Page Language="C#" AutoEventWireup="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label ID="Test1"/></asp>
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
Test1.Text = "Hello World; the time is now" + DateTime.Now.ToString();
}
</script>
</div>
</form>
</body>
</html>
Any assistance on why I'm receiving this error message would be greatly appreciated.
You need to include the runat="server" attribute on your asp control, otherwise your code-behind does not recognize it.
Note, you can add this attribute to plain html elements as well.
<label id="myLabel" runat="server">text</label>
myLabel.InnerText = "stuff";
In addition to including the runat tag, you didn't close the tag correctly
<asp:Label runat="server" ID="Test1"></asp:Label>
or
<asp:Label runat="server" ID="Test1"/>

Problem reseting a form on client side with ASP.NET

I'm trying to reset my form using javascript on client side. The code looks like this:
<%# Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script type="text/javascript" >
function Reset() {
TextBox1.text = "";
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Button" OnClientClick="Reset()" />
</div>
</form>
</body>
</html>
This of course isn't working, I get the error that Button1 is undefinded. I tried looking control's name within browser (by viewing page source) and using that instead of its ID but that didn't work either.
you need to get the value using getElementById
var mybutton= document.getElementById('Button1');
mybutton.value = ""
I advise you to use jQuery for your javascript code. It's a standard anyway.
After you reference jQuery, you may rewrite your JavaScript as follows:
<script type="text/javascript" >
function resetForm() {
$("#<%=TextBox1.ClientID %>").val("");
}
</script>
If you still do not want to use jQuery, then you need to access your element using its client ID like following:
<script type="text/javascript" >
function resetForm() {
document.getElemenyById("<%=TextBox1.ClientID %>").value = "";
}
</script>
Also, as #Jon pointed out, you need to either rename your OnClientClick value to resetForm() or rename your JavaScript function.

UserControl Raise Events

I add an onfocus event to a web user control (.ascx) expection it to raise event when it gets focus but it doesn't. Is it not intended to work this way and how can I get it to raise the event? Here is sample below, but it doesn't work.
<%# Control Language="vb" AutoEventWireup="false" CodeBehind="WebUserControl1.ascx.vb"
Inherits="RaiseEventUserControl.WebUserControl1" %>
<div style="padding: 5px; background-color: #C0C0C0">
TB1:
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<br />
<br />
TB2:
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
</div>
<%# Register Src="WebUserControl1.ascx" TagName="WebUserControl1" TagPrefix="uc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script type="text/javascript">
function RaiseEvent(obj) {
alert("Event was raised for: " + obj.id)
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<uc1:WebUserControl1 ID="WebUserControl11" runat="server" onfocus="RaiseEvent(this)" />
<br />
<uc1:WebUserControl1 ID="WebUserControl12" runat="server" onfocus="RaiseEvent(this)" />
</div>
</form>
</body>
</html>
This can be achieved using jquery. In your head element, add the following:
<script type="text/javascript" src="http://code.jquery.com/jquery-1.5.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$('input[name^="WebUserControl"]').focusin(function () {
$(this).val("i have focus");
});
});
</script>
What this does is, grabs the input elements whose name starts with "WebUserControl" and adds a "got focus" event. The handler for that event places "i have focus" as the value for that input element.
The way that this would be rendered to the page is that a "onFocus" attribute would be added to the div that represents the control. This is not something that supports focus. You might add the "onFocus" item to say your first text field in the control or something similar to be able to raise the event if needed.

Removing READONLY attribute from textbox using client side code

I have a multiline textbox that by default, is set to ReadOnly. I would like a button on the page to change the control to allow it to be edited. I would like this code to run on the client side because the page renders slowly and I'd like to avoid the post back.
The problem I'm having is the javascript code that I wrote to remove the readonly attribute appears to have no effect. I posted a stripped down example that illustrates the problem for your review.
<%# 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">
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Test</title>
<script type="text/javascript" language="javascript">
function EnableEditing() {
var e = document.getElementById("<%=TextBox1.ClientID%>");
var result = e.removeAttribute("readonly");
alert(result);
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div> </div>
<asp:TextBox ID="TextBox1" runat="server" ReadOnly="True" TextMode="MultiLine">test</asp:TextBox>
<input id="Button1" onclick="EnableEditing()" type="button" value="Remove RO" />
</form>
</body>
</html>
TextBox1 is the server side id,
try
var e = document.getElementById("<%=TextBox1.ClientID%>");
var result = e.removeAttribute("readonly",0);
or if you dont want the caseinsensitive search
var result = e.removeAttribute("readOnly");//note upercase Only
Use var e = document.getElementById("<%=TextBox1.ClientID%>");
Also, if you want to read the modified text on postback, you can't set the readonly attribute on the server control. You have to set it on the client only, as in: TextBox1.Attributes("readOnly") = "readOnly";

Is it possible to call a server-side event on a parent page when a child page closes?

I have a parent page with two data controls. I want to be able to open a child window, do something on it, and when it closes I want to rebind only one of the two data controls on the parent page. I have the control I want to update within an UpdatePanel so would like to call rebind it and call UpdatePanel.Update().
From a child window, you can't actually "call" a server side function for the parent page, however you can use some javascript to invoke client side functions on that page.
On the parent page:
<script language="Javascript" type="text/javascript">
function CallAlert()
{
alert("This is parent window's alert function.");
}
</script>
On the child page:
<script language="Javascript" type="text/javascript">
function CallParentWindowAlert()
{
window.opener.CallAlert();
return false;
}
</script>
In the example you provided, in particular where you have an UpdatePanel, you've actually left yourself a few options here. If the UpdatePanel is set with some form of trigger to force it to update, be it all children or just specified ones, in your parent function you can force a postback on one of those controls. Ultimately, the parent pages javascript function should have some form of a __doPostBack() call, referencing the id of a control and some (empty) parameter, however you'd probably be better off generating that javascript with codebehind via:
Page.ClientScript.GetPostBackEventReference(control, null);
Once you put that together, it's all a matter of tying the actual invocation to whatever client side event you want on your child page, be it onUnLoad() or in some custom function you call.
Try this out all you got to do is call __doPostBack on the parent page targeting the update panel or something in the update panel.
Parent Code:
<%# Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h1>Parent Window</h1>
Time:
<%= DateTime.Now.ToString() %>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
Update Panel Time<%= DateTime.Now.ToString() %>
<br />
<asp:Button ID="Button1" Text="Submit" runat="server" />
Click To Open Child Window
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
</html>
Child Code:
<%# 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">
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script type="text/javascript" language="javascript">
function UnloadMe() {
if (opener) {
opener.__doPostBack("UpdatePanel1", "");
}
}
</script>
</head>
<body onunload="UnloadMe()">
<form id="form1" runat="server">
<div>
<h1>Child Window</h1>
</div>
</form>
</body>
</html>

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