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Dynamically change the Body for a component in Blazor

I'm trying to achive a search functionality for Blazor-server where the idea is to use it anytime on the site by typing on a search box which causes the page to change the #Body for a component that shows the results of the search.
Currently I'm able to do the search well on the MainLayout but this is by having already a list there and the Body component either below or on top. What I need is to only show the List AFTER I input something on the search bar and to replace it with the Body.
Here is what works but whithout the issue I am having.
<input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search" #oninput="(ChangeEventArgs e)=>SearchHandler(e)" />
<BrowseListShared #ref="BrowseListShared" />
#Body
code{
public string Searched { get; set; }
protected BrowseListShared BrowseListShared;
public void SearchHandler(ChangeEventArgs e)
{
Searched = e.Value.ToString();
BrowseListShared.UpdadeMe(Searched);
}
}
And this is my attempt at trying to make the replacement which gives me the error "Object reference not set to an instance of an object.", the Error shows when I type something in the search box.
<input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search" #oninput="(ChangeEventArgs e)=>SearchHandler(e)" />
#if (setVisible){
<BrowseListShared #ref="BrowseListShared" />
}else{
#Body
}
code{
public string Searched { get; set; }
protected BrowseListShared BrowseListShared;
private bool setVisible=false;
public void SearchHandler(ChangeEventArgs e)
{
if (e != null && e.Value.ToString() != ""){
setVisible = true;
}else{
setVisible=false;
}
Searched = e.Value.ToString();
BrowseListShared.UpdadeMe(Searched);
}
}
Hope someone can give me some direction to deal with this, thank you.
Edit:
Adding if(BrowseLit != null) to avoid error does make it work with some issues.
1- the first character makes so it shows just the list without the search because on the first character the code doesnt have the reference yet for the BrowseListShared so it skips the BrowseListShared.UpdateMe for the first tipe.
2- On deleting the text in the box completely until its blank and typing again will cause this error 'Cannot access a disposed object.'

There shouldn't be an issue to add a small if-block, the following is a basic concept that works for me:
<button #onclick="#( () => test = !test )">test</button>
#if (!test)
{
#Body
}
else
{
<span>some other search content - use a component here
and pass the data as a parameter to it, and its OnParametersSetAsync
can fetch needed data: #test</span>
}
#code{
bool test { get; set; }
}
I would also suggest you try using parameters for the search details instead of a reference.
If you want to show a particular page with search results, you can consider navigating the user to that page (e.g., pass the search query as a route parameter to it) - then it will render only what you want in the #Body - which can range from nothing, to search results, to a lot of other things.

Textbox.text always returns empty string in code behind c#

Well, I'm trying to do a simple command: get the text from TextBox. I've searched for that, but every answer failed for me.
In my code aspx:
<form id="form1" runat="server" method="post">
<div class="form">
<div class="form-search ngen-search-form">
<span id="search-trigger" class="form-search-submit">
<img src="Imagens/Lupa_Icon 2.png" id="lupa"/>
</span>
<asp:TextBox ID="txtBoxSearch" runat="server" CssClass="form-search-input" placeholder="Pesquise..." ViewStateMode="Enabled"/>
</div>
</div>
</form>
I have a Javascript function that verifies what key my client pressed:
$(document).keypress(function(e) {
if(e.which == 13){
if( document.getElementById("txtBoxSearch").value == "" ) return true;
else {
<% setSearch(); %>
document.getElementById("testeArv").innerHTML='<%=search.ToString()%>';
return false;
}
}// First if
});
And finally, my function setSearch() in code behind is:
public void setSearch( )
{
if( !Page.IsPostBack ) {
search = txtBoxSearch.Text;
}
}

Main mistake is about how to call codebehind method in jQuery. Take a look here
to know how to do it. Summary: you need ajax
Then you will have to keep in mind that it does Page.IsPostBack.
With !Page.IsPostBack you are saying "first page access" but when you press the button !Page.IsPostBack will be false. If you try the same example so:
public void setSearch( )
{
if(!Page.IsPostBack) {
// First page access
search = txtBoxSearch.Text;
} else {
// The page has been reloaded
search = txtBoxSearch.Text;
}
}
It will work. (The else will run)
I am not sure but I have tried it (without jQuery) with a button and the same error occurs. You want to run the function when the Enter is pressed so the page will do the reload. Take a look here.
Maybe it helps you in some way.

It's the <form> tag blocking your way to get the value in post back. Remove the <form> tag and use AutoPostBack=true for your text box. You won't need to use jQuery to catch the event and the value.

You can't call code behind code from client-side code. They execute on different machines.

Set Html Checkbox checked from code behind without runat=server

I have checkboxes in my aspx page as :
<input type="checkbox" name="daySelectors" value="monday"/>
<input type="checkbox" name="daySelectors" value="tuesday"/>
<input type="checkbox" name="daySelectors" value="wednesday"/>
I am not using CheckBoxList control as these checkboxes are at different areas in my html and i need value of only selected checkboxes.
Now, I can get the values of selected Checkboxes using
String dayselector = Request.Form["daySelectors"];
It works fine until here. The problem is how can i make the checkboxes checked from code behind i.e. my aspx.cs page. The scenario is when i come to this page i have the checkboxes values that need to be checked by default. How can i do this using the values.
One way that comes to mind is i can trigger a jquery/ Javascript function from .cs passing in the values. In that case how can i set checkbox checked using their values from jquery.

Finally i just called a Javascript method from my .cs file using
ScriptManager.RegisterClientScriptBlock(this, typeof(string), "uniqueKey","SetCheckBox('sunday');",true)
and to the JavaScript method passed in the value of CheckBox that needs to be checked :
function SetCheckBox(value) {
$("input:checkbox[value=" + value + "]").attr("checked", true);
}

You cannot. If the control is not runat=server, you don't have access to it in code behind.

If you absolutely don't want runat="server" (but I think your reason for not wanting to use it might be based on a misconception), you can always have some custom properties in your Page class and then pump attributes (like "selected") straight into your checkbox markup...
<input type="checkbox" selected="<%=SelectedAttribute%>" .... />

In the checkbox tag:
in the codebehind:
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
try
{
if (Request.Form["Archived"].ToString() == "1")
{
Session["checkboxstate"] = " checked='checked' ";
}
}
catch (Exception eee)
{
Session["checkboxstate"] = "";
}
}
}
Worked for me.

Enter Does Not Work For Submit, ASP.NET Page Refreshes and Doesn't Search

I am working with an ASP.NET site with a C# back end. There is a .Master page where the tag is, and other search pages on the site will search when you hit enter after filling out the form. However we have one page that has a few text boxes and when you hit enter to search, it appears to just refresh and reload the page without searching. In order to search you have to hit the search button (which is an igtxt:WebImageButton ). All of the solutions I have found to this issue so far involve people using javascript to call some kind of function on submit. As far as I know there is no javascript being called when you hit the search button, it is all in the C# code. Once again I find myself searching SO and other sites for an answer but none of the solutions seem to fit my situation. The form tag is as follows:
<form id="form1" runat="server">
The web image buttons call a btn_SearchClick function that runs the search code. But since the form is started in the .Master file I can't edit that as it would effect all other pages as well. Is there any way to have enter call the btn_SearchClick from the form without having to put it in the form tag? I'm not sure what would've changed to cause this behavior on one page and none of the others.

if (!IsPostBack)
{
TextBox1.Attributes.Add("onKeyPress",
"doClick('" + btnSearch.ClientID + "',event)");
}
<SCRIPT type=text/javascript>
function doClick(buttonName,e)
{
//the purpose of this function is to allow the enter key to
//point to the correct button to click.
var key;
if(window.event)
key = window.event.keyCode; //IE
else
key = e.which; //firefox
if (key == 13)
{
//Get the button the user wants to have clicked
var btn = document.getElementById(buttonName);
if (btn != null)
{ //If we find the button click it
btn.click();
event.keyCode = 0
}
}
}
</SCRIPT>
or u can use default button.it's work while cursor's in this box
protected void Page_Load(object sender, EventArgs e)
{
this.Form.DefaultButton = this.btnSubmit.UniqueID;
}

Add some jquery to control the Enter key behavior on your textbox. Something like this:
$(function() {
$('#<%=txtTextbox.ClientID%>').keypress(function (e) {
if (e.which == 13) {
e.preventDefault();
$('#<%=btn_SearchClick.ClientID%>').click();
}
});
});

How to make textbox visible when previous textbox contains text

I have a WebForm in which i need to place around 30 textboxes mainly to enter barcode scanned data. I am making only the first textbox visible and i want the next textbox to be visible only when the previous textbox is filled with some text. I tried using 'If' condition as well in the textbox on selected change but it doesn't work. Any solutions?

You should use java-script for this because if you will use server side function for this then It will go to server so many times by this your application performance also will decrease.
So create a java-script function that will accept one argument. This argument will take next text box id (text box u want to display).
call this javascript function like this:- onkeyup="calgrid(this,"TextBox2");"
pass nexttextbox id in place of TextBox2...
<script type="text/javascript" language="javascript">
function calgrid(firsttextbox,nexttextbox)
{
var id=firsttextbox.id;
var lastindex= id.lastIndexOf("_");
var strclnt=id.slice(0,lastindex+1);
var txtboxvalue=document.getElementById(firsttextbox).value;
if(txtboxvalue!="")
{
document.getElementById(strclnt+nexttextbox).style.visibility='visible';
}
else
{
document.getElementById(strclnt+nexttextbox).style.display = "none";
}
}
</script>
note:- If you will do visible=false from textbox property then we cannt do visible=true from javascript. So Set style for all textbox style="display:none"

You can resolve your problem by Jquery.
I have make a sample code where i have take four Textbox. Initially only first text box is visible in Web form, when user enter some values in first TextBox next Textbox is automatically display if Previous textbox have a value if not next textbox is not visible.
Sample code is given below :
<input type="text" />
<input type="text" />
<input type="text" />
<input type="text" />
$('input:text:not(:eq(0))').hide()
$('input').on("change paste keyup", function () {
if ($(this).val().length > 0) {
$(this).next().show();
}
else
{
$(this).next().hide();
}
});
I have made sample application for same ,please click on given link for Demo
See Demo application
It's at Client side code so its performance is so fast rather than Server Side.
Please vote me if you feel your problem is resolved by my idea.

I'd name these text boxes similarly like "textbox1", "textbox2", "textbox3" so you can easily find the index of current text box. Then you can use KeyDown event to control what will be shown and what not. This is not a working example but it should give you a good direction.
int currentIndex = 1;
private void TextBox1_KeyDown(object sender, KeyEventArgs e)
{
TextBox t = Controls["TextBox" + (currentIndex + 1).ToString()] as TextBox;
t.Visible = true;
currentIndex +=1;
}

Use can use Keydown event in your first textbox

try this code
initially set flag=1 as first textbox is going to be by default visible
private void visibleTextBox(Control c)
{
int flag = 1;
foreach (Control c1 in c.Controls)
{
if (c1.GetType() == typeof(TextBox))
{
if (flag == 1)
{
((TextBox)c1).Visible = true;
}
else
{
((TextBox)c1).Visible = false;
}
if (((TextBox)c1).Text != "")
{
flag = 1;
}
else
{
flag = 0;
}
}
}
}

Comparatively simple solution in JavaScript. The code should be somehow like this.
Define onchange event on text boxes like this:
<asp:TextBox ID="txt1" runat="server" onchange="show('txt1', 'txt2');"></asp:TextBox>
<asp:TextBox ID="txt2" runat="server" onchange="show('txt2', 'txt3');" Style="visibility: hidden;"></asp:TextBox>
Then use this JavaScript code to show the next TextBox conditionally. Put this code in the head tag of the page:
<script type="text/javascript">
function show(txtCurrent, txtNext) {
var valueCurrent = document.getElementById(txtCurrent).value;
//alert(valueCurrent);
if (valueCurrent.length > 0) {
document.getElementById(txtNext).style.visibility = 'visible';
}
else {
document.getElementById(txtNext).style.visibility = 'hidden';
}
}
</script>