Develop Reference

Combobox specific item c#

I have many items in my combobox
one of them is a item called "Alert"
i want the code to know that when the selected item is "Alert" it launches an event
i work with c# and visual studio 2019 winform

Add the SelectedIndexChanged event to the Combobox.
You can get the details like below.
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
ComboBox comboBox = (ComboBox)sender;
int selectedIndex = comboBox.SelectedIndex;
int selectedValue = (int)comboBox.SelectedValue;
string selectedItem = (string) comboBox.SelectedItem;
}

How to get Row Id in RepositoryLookupEdit_ValueChanged event

I have gridcontrol that has a RepositoryLookupEdit in one of the columns. I can get the value of RepositoryLookupEdit after changed, but I dont know how to get the which row's RepositoryLookupEdit value changed. How can I get the Row ID?
With the code below, I can get the RepositoryLookupEdit value.
private void repositoryItemLookUpEdit1_EditValueChanged(object sender, EventArgs e)
{
LookUpEdit edit = sender as LookUpEdit;
var row = edit.Properties.GetDataSourceRowByKeyValue(edit.EditValue);
}

Since repositoryItemLookUpEdit isn't restricted to GridControls you cannot get the row handle from this event. You however have other possibilities.
First, if the edit is done by the user, you can use the ColumnView.GetFocusedRow() method to get the current grid row.
If however the edit value is changed via code it will also be changed in the grid so you can now use the ColumnView.CellValueChanged event.
private void repositoryItemLookUpEdit1_EditValueChanged(object sender, EventArgs e)
{
LookUpEdit edit = sender as LookUpEdit;
var row = edit.Properties.GetDataSourceRowByKeyValue(edit.EditValue);
gridRow = gridView.GetFocusedRow() as MyDataRow
}

How to get EditValue from RepositoryItemsLookUpEdit

How to get EditValue which is unique and Binded using DataSource ValueMember with RepositoryItemLookUpEdit in gridColumn and on changing value fill the other fields retrieved from database.

You can handle the RepositoryItemLookUpEdit's EditValueChanged event, in which you can obtain the current editor's value
private void repositoryItemLookUpEdit1_EditValueChanged(object sender, EventArgs e)
{
object value = (sender as LookUpEdit).EditValue;
/// your code here
}

access to property on selection winforms combobox

One article has Name and Price properties. I use Name property to display articles inside combobox cmbDataList like this
public Form1()
{
InitializeComponent();
cmbDataList.DataSource = GetData();
cmbDataList.DisplayMember = "Name";
}
After user selected the preffered article I want to use it's Price property to assign to textbox on the same form. So, how to access to that Price property?
private void cmbDataList_SelectedIndexChanged(object sender, EventArgs e)
{
//var sel = cmbDataList.SelectedItem;
}

You have to cast SelectedItem to proper object.
private void cmbDataList_SelectedIndexChanged(object sender, EventArgs e)
{
var sel = (YourObject)cmbDataList.SelectedItem;
txt.Text = sel.Price.ToString();
}

Unless all names are unique, you're going to need a unique identifier to reference, for example an articleID.
From here, set the ComboBox's ValueMember like so;
cmbDataList.ValueMember = "ID";
then you can get your value on the event handler;
private void cmbDataList_SelectedIndexChanged(object sender, EventArgs e)
{
var sel = cmbDataList.SelectedValue;
//From here you're going to need to find your article with that particular ID.
}
Alternatively. You could have your DisplayMember as the article name, and the price as the ValueMember, then get it in the event handler for SelectedIndexChanged in the same way i put above. SelectedValue will then return the price;
cmbDataList.ValueMember = "Price";
private void cmbDataList_SelectedIndexChanged(object sender, EventArgs e)
{
var yourSelectedPrice = cmbDataList.SelectedValue;
}

Assuming GetData() returns a table, you need to write the ValueMember also... like this:
InitializeComponent();
cmbDataList.DataSource = GetData();
cmbDataList.DisplayMember = "Name";
cmbDataList.ValueMember = "Price";
Now, your selected display will be synced with the value and you will be able to use it..
Get more info in here:
Populate combobox

You Need to set ValueMember You can set in this way
cmbDataList.ValueMember = "ID";
then you write the code on cmbDataList_SelectedIndexChanged Event
May be this will help you
var sel = cmbDataList.SelectedValue

FormView Data Binding

I have for fields in my datasource that I want to combine and display in one label field. I have added a procedure to capture the databinding action but I don't how to get the data out of the datasource. I am displaying this information on a FormView is that makes anly difference. Can I get an example in c#?
For example -
protected void DisplayPayOut(object sender, EventArgs e)
{
Label Payout = FormView1.FindControl("PayoutLabel") as Label;
Payout.Text = datasource.field1 + datasource.field2;
}

I'm not fully sure but it seems like you're looking for something like the following:
protected void DisplayPayOut(object sender, EventArgs e)
{
Label Payout = FormView1.FindControl("PayoutLabel") as Label;
object dataItem = DataBinder.GetDataItem(FormView1);
Payout.Text = DataBinder.Eval(dataItem, "field1NameHere").ToString() + DataBinder.Eval(dataItem, "field2Namehere").ToString();
}