Develop Reference

Which link is clicked in asp.net gridview row

I am adding two links and some plain text in same cell of gridview, I also have gridview_SelectedIndexChanged function which is called when any of the link is clicked and based of the value from grid I am running my db queries. gridview is also created dynamically so can have different number of rows.
Is there a way to know Link1 or Link2 is clicked in gridview_SelectedIndexChanged function?
protected void gridview_SelectedIndexChanged(object sender, EventArgs e)
{
if (Link1.Clicked)
{do this}
elseif (Link2.Clicked)
{do this}
}

You would want to track which link is clicked by using an ASP.NET control
<asp:LinkButton ID="Link1" runat="server" Click="Link1_Click" />
in your html
Then add an event handler in your backend like
public void Link1_Click(object sender, EventArgs e)
{
//add variable marking this link was clicked
link1_clicked = true;
Response.Redirect("Link1Destination.aspx");
}
and do the same for link2
<asp:LinkButton ID="Link2" runat="server" Click="Link2_Click" />
public void Link2_Click(object sender, EventArgs e)
{
//add variable marking this link was clicked
link2_clicked = true;
Response.Redirect("Link2Destination.aspx");
}
Add the boolean variables link1_clicked and link2_clicked to the top of you backend code. Then when you need to check what has been clicked you can filter though your boolean variables to see what is marked true as clicked with a for-loop.
Basically the Event handlers are your if clicked statements.

Hide button on drop down selection -1

I need my create button to be hidden unless a facility is selected in my dropdown. When it is at -1 message i need my button to be hidden.
Code for button
<asp:Button ID="btnCreate" runat="server" Text="Create New" Width="89px" Font-Size="X-Small" OnClick="btnCreate_Click" />
Drop down code
private void ResetForm()
{
try
{
//facility dropdown
ddlFacility2.Items.Clear();
ddlFacility2.DataSource = this.DataLayer.model.MS_spGetFacilityInfo(null).OrderBy(x => x.FacilityName);
ddlFacility2.DataTextField = "FacilityName";
ddlFacility2.DataValueField = "FacilityID";
ddlFacility2.DataBind();
ddlFacility2.Items.Insert(0, new ListItem("All Facility Records..", "-1"));
BindGrid();
}
catch (Exception ex)
{
this.SetMessage(ex.ToString(), PageMessageType.Error);
AISLogger.WriteException(ex);
}
}

in first time page load if the default value selected is -1 you can set your button visible false as default.
in your droupdown list selected index change event you can enable/dissable button based on droupdown list selected value.

Add a OnSelectedIndexChange event to your dropdown list or add a clientside event to your dropdownlist. Double Click on your ddl you will see a function named ddlFacility2_OnSelectedIndexChanged in you code behind and add the below code to it.
Add AutoPostBack=true to you ddl
protected void ddlFacility2_OnSelectedIndexChanged(object sender, EventArgs e)
{
if(ddlFacility2.SelectedIndex>-1)
{
btnCreate.Enabled = true;
}
else
{
btnCreate.Enabled = false;
}
}

You can wire up a JQuery script that can bind to your DropDownList's selected value...
In this example, the button's visibility is bound on a click from another button:
$('#Button1').bind("click", function() {
$("#Button2").hide();
});
I dont know the exact syntax to use for the binding to selected value, but the above code should be a good place to start.

Change the value of a textbox in a template field from event outside of GridView

I need to be able to change the value of a TextBox(s) in a GridView template field from a TextChanged event. So the user can enter some text in a TextBox outside of the Gridview and then the TextBox(s) in the GridView gets updated to what the user entered.
This is what I need to do:
protected void TextBox1_TextChanged(object sender, EventArgs e)
{
template_text_box1.Text( in template field ) = TextBox1.Text << (TextBox1)( outside of gridview )
}
I have tried FindControl. This needs to happen without using any of the GridView events. I am just stumped. Could someone point me in the right direction? Maybe some JavaScript?

I believe that you would want to define a separate TextBox for the display and do something like the following:
double value1;
private void template textBox1_TextChanged(object sender, TextChangedEventArgs e)
{
if textBox1.Text (Double.TryParse(textBox1.Text, out value1))
{
textBox15 = value1.ToString();
}
}
This way you can make your other TextBox outside the grid and be able to call it and set to the value that is inputted.

On the .Aspx page, in the GridView column template TextBox add a CSS class.
<asp:TextBox ID="TextBox1" runat="server" CssClass="box-to-change" Text=""></asp:TextBox>
Also on the .Aspx page add a JavaScript function that uses jQuery:
<script type="text/javascript">
function updateAllTextboxes(value)
{
$('input.box-to-change').val(value);
}
</script>
In the code-behind add the JavaScript function as a client OnChange event (will not require PostBack).
otherTextBox.Attributes["onchange"] = "updateAllTextboxes(this.value)";

Disable Postback on button ASP.NET c#

here is an example of what I am doing
Page Load
{
//Adds items to a panel (not an updatepanel just a normal panel control)
}
protected void btnNexMod_Click(object sender, EventArgs e)
{
// Calls DoWork() and Appends more items to the same panel
}
My problem is that the asp:button is doing a postback as well as calling DoWork()
Therefore, re-calling my page load, re-initializing my panel :(
I want my items that I have added to the panel to stay there!
All help appreciated, not looking for a hand you the answer kind-of deal. Any steps are appreciated thanks!
Here is an exact example of my problem.
protected void Page_Load(object sender, EventArgs e)
{
CheckBox chkbox = new CheckBox();
chkbox.Text = "hey";
chkbox.ID = "chk" + "hey";
// Add our checkbox to the panel
Panel1.Controls.Add(chkbox);
}
protected void Button1_Click(object sender, EventArgs e)
{
CheckBox chkbox = new CheckBox();
chkbox.Text = "hey";
chkbox.ID = "chk" + "hey";
// Add our checkbox to the panel
Panel1.Controls.Add(chkbox);
}
Only thing on the page is a empty panel and a button with this click even handler.
I have also tried this and it still doesn't work. Now its clearing the initial item appended to the panel.
if (!Page.IsPostBack) // to avoid reloading your control on postback
{
CheckBox chkbox = new CheckBox();
chkbox.Text = "Initial";
chkbox.ID = "chk" + "Initial";
// Add our checkbox to the panel
Panel1.Controls.Add(chkbox);
}

If you're adding controls to the Panel dynamically, then you'll have to recreate the controls at every postback, and make sure to assign the same IDs to the controls so that ViewState can populate the values. It's usually best to recreate dynamic content during OnInit, but this can be difficult in some situations.
One of my favorite tools is the DynamicControlsPlaceHolder, because you can add dynamic controls to it and it will persist them automagically, without any additional coding required on the page. Just add controls to it, and it will do the rest.
Here's the link:
http://www.denisbauer.com/Home/DynamicControlsPlaceholder
As for preventing your button from performing a postback, use OnClientClick and return false.
OnClientClick="return false;"

You could use
<asp:LinkButton OnClientClick="javascript:addItemsToPanel();return false;"
thus using a javascript function to add them. That's how I've got around that problem.

You can also try this:
Page Load
{
if (!this.IsPostBack) // to avoid reloading your control on postback
{
//Adds items to a panel (not an updatepanel just a normal panel control)
}
}

you can do like this...
ASPX code:
<asp:LinkButton ID="someID" runat="server" Text="clicky"></asp:LinkButton>
Code behind:
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
someID.Attributes.Add("onClick", "return false;");
}
}
What renders as HTML is:
<a onclick="return false;" id="someID" href="javascript:__doPostBack('someID','')">clicky</a>

You are correct, you will have to add the new items to the Panel after a PostBack. That is the nature of the .NET pipeline.
If you use a data bound control, like a Repeater, to display the panel contents, then the button click handler just needs to rebind the control and it will all work out correctly.

Changing the asp:Button to a asp:LinkButton solved my issue.

I think, it is better use the Ajax Update panel. And put your button in to that.
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button1" />
</ContentTemplate>
</asp:UpdatePanel>

End user add values to a dropdownlist?

I'm populating a dropdownlist in c# asp.net-MVC from a SQL table using Linq2Sql. I'd like for the user to be able to enter something that isn't in the list into the drop down and have it add to the table. Is this possible?

Sounds like you need to add a radio button labeled "Other". When the user clicks the radio button a text box would appear that allows the user to input a new value that you can save to your DB and display in the drop down.
EDIT:
Quick snippet to enable the control using JavaScript:
<script language="javascript" type="text/javascript">
function radioclicked() {
textObj = document.getElementById('<NAME OF TEXT BOX');
textObj.disabled = false;
}
</script>
You can use a check box instead of a radio button so that the enabled property can be toggled.
To completely hide the text box then you will have to look into jQuery/Ajax.

Why can't we use a lightweight Add-on like www.combodropdown.info for this purpose? You can even consider AutoComplete plugin from jQuery, if your app already references jQuery.

Also a combobox will allow a user to enter a value in addition to picking from a list.

My MVC is not so so, but I assume this still applies as MVC is just model view controller.
What if you throw a drop down on your form visible=true, and a textbox on your form visible =false.
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True"
onselectedindexchanged="DropDownList1_SelectedIndexChanged">
</asp:DropDownList>
<asp:TextBox ID="TextBox1" runat="server" Visible="False"></asp:TextBox>
Fill your drop down:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
List<int> s = Enumerable.Range(1, 10).ToList();
DropDownList1.DataSource = s;
DropDownList1.DataBind();
DropDownList1.Items.Add("Other");
}
}
Add an event to handle if someone selects other. If they do make the textbox visible:
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
switch (this.DropDownList1.SelectedItem.Text)
{
case "Other":
this.TextBox1.Visible=true;
break;
default:
this.TextBox1.Visible=false;
break;
}
}
Now you can enter your value and re-store back to the db.