Develop Reference

Can't update using FindControl

I have a TextBox within my EditItemTemplate in my listview_car:
<EditItemTemplate>
<asp:TextBox ID="txt1" runat="server" Text='<%# Bind("photo1") %>' Visibile="true">
</asp:TextBox>
</EditItemTemplate>
Now in the code I have this in my ItemUpdating event:
protected void listview_car_ItemUpdating(object sender, ListViewUpdateEventArgs e)
{
var txt1 = listview_car.Items[0].FindControl("txt1") as TextBox;
txt1.Text = "newImage";
}
Now I have debugged it and the value that is showing from my DB is correct, then when I set it from the code using txt1.Text = "newImage"; it shows it has updated the textbox in the Auto's however it does not update in the DB, but the strange thing is when I type in the textbox and click the edit button it updates but doesn't update when I set the string in the code?
Does anyone know what I am doing wrong?

When ItemUpdating() is called all values were already collected in the NewValues collection. To modify any of values you should modify e.NewValues
protected void listview_car_ItemUpdating(object sender, ListViewUpdateEventArgs e)
{
e.NewValues["key"] = "newImage";
}
where "key" is a name of the key (not a name of the control) which is usually a column name. You could also use an index 0,1,2...

In listview_car_ItemUpdating, first update the database, then call whatever method you used to bind your controls to the database when the page first loaded. This will retrieve the new value of photo1 from the database and bind it to txt1.

Checkboxlist loop is not working

I have a dropdownlist control and a button in asp.net page. The dropdownlist is populated from a method. If I select any item other than the first item, after clicking the button, I lose the selected item in the DDL and it selects the first item and also I am getting the value of the first item only in the button click event. How can I fix the problem?
<asp:DropDownList ID="userDropDown" runat="server" DataTextField="CustomerName" DataValueField="CustomerId">
</asp:DropDownList>
protected void Button1_Click(object sender, EventArgs e)
{
if(!page.isPostBack)
{
userDropDown.DataSource = CC.GetCustomers();
userDropDown.DataBind();
}
}

i think you must have bind userDropDown in Page_Load event without condition
if (!IsPostBack)
Please put dropdown binding part inside if (!IsPostBack) condition then it should work

Please bind dropdownlist values inside the if(!ispostback){} or
after submitting button please bind updated field to dropdownlistname.text

It sounds like you are binding your DropdownList to your datasource at ever request. Instead bind it only if Page.IsPostBack is false like below; (You may not need ObjectDataSource)
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
//bind your datasource here (something like below)
userDropDown.DataSource = GetCustomers();
userDropDown.DataBind();
}
}
As soon as DataBind() method is called it will lose posted data of that object and the FirstItem will be selected by default.

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)";

reset selectedvalue when textbox change

I have a textbox and a dropdownlist
the textbox has
<asp:TextBox ID="TxtInizioPeriodo" runat="server"
ontextchanged="InizioPeriodo_TextChanged" AutoPostBack="true" Width="100"></asp:TextBox>
i want if it changes the dropdownlist return to default value selected
i try to pur in page load this:
SelectDestinazione[i].SelectedValue = "";
but it now works.
how can i do?
thanks

In your code you have mentioned like
Array of Dropdownlist ie.,
SelectDestinazione[i].SelectedValue = "";
in the above code "i" selects dropdownlist object from the array of dropdownlists.
Kindly check that one. If its is the single dropdownlist box then use the below solution.
Copy & paste the below code in the server side during the text content change event.
protected void InizioPeriodo_TextChanged(object sender, EventArgs e)
{
SelectDestinazione.SelectedIndex = -1;
}

I assume SelectDestinazione is your dropdownlist
SelectDestinazione.clearSelection();