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Error on passing data back to Dropdownlist asp .net webform

I have a dropdownlist that cannot be used for editing purpose. When button Edit is clicked inside listview where data exists, data is supposed to pass back to dropdownlist and other textboxes where the form is located outside listview. Passing data back to textboxes is ok. The problem is dropdownlist data that I want to edit was added to dropdownlist as another record. Please take a loot at picture, and I have to reselect the correct one. Otherwise, that selected data (e.g. December in picture) has no datavaluefield and it stops running if I didn't choose bottom December and click Update button. Here is my code for dropdownlist for months. Any help is appreciated for this. Thank you.
public void BindMonth()
{
ddlStartMonth.DataSource = objUIHelpers.GetAllMonths();
ddlStartMonth.DataTextField = "StartMonthName";
ddlStartMonth.DataValueField = "MonthId";
ddlStartMonth.DataBind();
ddlStartMonth.Items.Insert(0, "Select Start Month");}
Then, I put this method in page load like this.
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindMonth();
}
}
This is listview data item editing
protected void lvEducation_ItemCommand(object sender, ListViewCommandEventArgs e)
{
switch (e.CommandName)
{
//Delete Method will be fired when command name "Delete" inside Listview is clicked.
case ("Delete"):
int EducationId = Convert.ToInt32(e.CommandArgument);//pass Id of Experience to identify datarow to delete
// DeleteEducationById(ExperienceId);//Call bind to delete method and pass ExperienceId as argument
break;
//Edit Method will fired when command name "Edit" inside Listview is clicked.
case ("Edit"):
EducationId = Convert.ToInt32(e.CommandArgument); //pass Id of Experience to identify datarow to edit
BindEducationDataToEdit(EducationId);//Call bind to edit method and pass ExperienceId as argument
break;
}}
This is part of method that triggers to pass back data to edit.
public void BindEducationDataToEdit(int EducationId)
{
Education edu = objJFUserBAL.GetEducationByIdToEdit(EducationId);
txtAdditionalInfo.Text = edu.AdditionalInfo.ToString();
ddlEndMonth.SelectedItem.Text = edu.mo.EndMonthName;
}
When selected data is posted back for editing, I have extra data like this.

You should not be updating the SelectedItem.Text. This is changing the displayed text. Instead you should be updating which item is selected.
If you do not have access to the value of the month name, you can do the following:
ddlEndMonth.Items.FindByText(edu.mo.EndMonthName).Selected = true;
which will select the item with the month text assuming one exists.
If it is possible to have an edu.mo.EndMonthName which does not exist in the list of items, you will want to do some checks for null and treat accordingly.

You have to fill a list manually, because auto binding is not going to let you put a "select your month" item unless you have one in your data base :
public void BindMonth()
{
List<Month> listOfMonth = new List<Month>();
Month fakeMonth = new Month();
// you need to see your own
//code and try to make a fake month with these parameters you want
fakeMonth.StartMonthName = "Select Start Month";
fakeMonth.MonthId = 0;
listOfmounth.Add(fakeMonth);
foreach(Month m in objUIHelpers.GetAllMonths())
{
listOfMonth.Add(m)
}
ddlStartMonth.DataSource = listOfMonth;
ddlStartMonth.DataTextField = "StartMonthName";
ddlStartMonth.DataValueField = "MonthId";
ddlStartMonth.DataBind();
ddlStartMonth.Items.Insert(0, "Select Start Month");}
}

How do I select last edited row using a button

I have a project to register customers using a DataGridView and It has 3 buttons:
"add" adds the values from the textbox
"delete" deletes the selected value in the DataGridView
"new" generates the next id number (they're consecutives) and clears all the textboxes fields
I think of adding a button named "cancel" to revert changes generated by the button "new" and it has to select the last edited row and show its cells values in the textbox.
I made a "cancel" button to select the last row in the list, but the last row in the list is not always the last edited
I'm using Windows Forms, not using a database.
private void bttn_cust_cancel_Click(object sender, EventArgs e)
{
if (dgv_customer.Rows.Count > 0)
{
dgv_customer.Rows[dgv_customer.Rows.Count - 2].Selected = true;
int i;
i = dgv_customer.SelectedCells[0].RowIndex;
txt_cust_clave.Text = dgv_customer.Rows[i].Cells[1].Value.ToString();
txt_cust_name.Text = dgv_customer.Rows[i].Cells[2].Value.ToString();
txt_cust_country.Text = dgv_customer.Rows[i].Cells[3].Value.ToString();
}
int currentType = Convert.ToInt32(txt_cust_id.Text);
txt_cust_id.Text = Convert.ToString(--currentType);
}

You could create a variable or class to hold the index and/or data of the last edited row. This class would be reinitialized every time the "New" button is pressed.

DataGridView selecting a specific row and retrieving all column values to an object array

I want to perform operation that On a button click event , Grid Currentrow entire data is passed to an object array
I have tried to search through following links :
DataGridView selecting a specific row and retrieving its values
Getting data from selected datagridview row and which event?
But they are talking about particular cell value
i tried to perform with code
DataRowView currentDataRowView = (DataRowView)grdGLSearch.CurrentRow.DataBoundItem;
DataRow row1 = currentDataRowView.Row;
But currentDataRowView is retrieving null
one of My Senior succesfully created a generic property GetSelectedRow()
it works like this :
var object =grdGLSearch.GetSelectedRow<T>();
and it has definition
public T GetSelectedRow<T>()
{
if (this.CurrentRowIndex == -1)
{
return default(T);
}
return (base.DataSource as BindingList<T>)[this.CurrentRowIndex];
}
But it is binded to only one Main grid , i also want to use this property to another Grids
I dont want data of a particular column , i want entire row data .. and dont want any iteration to be perform ...
Is there any single liner operation for this ?
Please suggest if I am missing any links

Since you are only showing 2 lines of code, I am really not sure exactly what is going on. First off, I get you want the entire row when you click some button. However, you never state how the current row is being selected.
In order to get the full selected row, you must have a selected cell. The MSDN documentation says this on the page for DataGridView.SelectedRow. So I am assuming that the user will click a cell, and you want the entire row. I would create a variable that will hold your selected row. Then when the user clicks the cell, automatically select the row and save it. Then when the button is clicked, just retrieve the the already saved row.
private DataGridViewRow selectedRow { get; set; }
Then have the event for when the user clicks a cell
private void grdGLSearch_CellClick(object sender, DataGridViewCellEventArgs e)
{
selectedRow = grdGLSearch.Rows[e.RowIndex];
}
Finally, the button click event
private void SubmitBtn_ItemClick(object sender, ItemClickEventArgs e)
{
// to target the specific data
var cellVal1 = selectedRow.Cells["SpecificCell1"].Value;
var cellVal2 = selectedRow.Cells["SpecificCell2"].Value;
}

C# List items empty after button clicked

I am trying to understand the lifecycle that is taking place here. I have a asp list view where I get item ids and write them to a list like so.
protected void ShareWith_OnItemBound(object sender, ListViewItemEventArgs e)
{
if (!IsPostBack)
{
if (e.Item.ItemType == ListViewItemType.DataItem)
{
ListViewDataItem currentItemId = (ListViewDataItem)e.Item;
System.Web.UI.WebControls.DataKey currentDataKey = this.lvShareWithPanel.DataKeys[currentItemId.DataItemIndex];
int FriendId = Convert.ToInt32(currentDataKey["SharedUserId"]);
CurrentList.Add(FriendId);
}
}
}
Where my list is defined outside the method
private List<int> CurrentList = new List<int>();
after, the user adds some new items to the list then click on an asp button to continue. I am running a comparison of the current list versus the new one but observing in debug after the button click I find that my list "CurrentList" is now empty. Why might the list, which is outside any method, be effected?
Thanks for the help understanding

The list has no state value. So you need to store the list in either ViewState, Session state or otherwise.
Every ASP.NET page loses its values between page loads and only gets them back from state or if you enter them every time. Most controls store values in ViewState, which is page specific. This link should help.

ASP.NET is stateless, therefore the data is lost during Postback. You need to keep track of your CurrentList manually e.g. in the Session/ViewState.
public List<int> CurrentList
{
get
{
return (List<int>)Session["CurrentList"] ?? new List<int>();
}
set
{
Session["CurrentList"] = value;
}
}

All page's objects will be disposed at the end of the page's life-cycle. So you need to create and fill your list on every postback (or store it in Session what i wouldn't recommend).
You could use page's PreRender event to ensure that all events are already triggered:
protected override void OnPreRender(EventArgs e)
{
// why do you need a list as field variable at all? I assume a local variable is fine
List<int> CurrentList = new List<int>();
foreach(var currentItemId in lvShareWithPanel.Items)
{
System.Web.UI.WebControls.DataKey currentDataKey = lvShareWithPanel.DataKeys[currentItemId.DataItemIndex];
int FriendId = Convert.ToInt32(currentDataKey["SharedUserId"]);
CurrentList.Add(FriendId);
}
// do something with the list
}
Note that you should not make it static as someone commented. That means you would use the same "instance" for every user and every request.
Here you can see all events:

You can store the list into ViewState and in PageLoad event, assign the List stored in ViewState to your class level List. This happens because of the Page Life Cycle where objects are disposed.

TabControl Saving on selected tab item changed

I need to save data in distinct TabItem every time when user switches to another tabitem.
I try to operate TabControl.SelectionChanged event, but there is no info about previously selected tab item.
So, how to get moment when user switches from my TabItem to another?

Use the Enter and Leave events of the individual tabs. If you need the enter event to fire on code start up then you may need to programmatically change the selected tab to one that is different than at design time.

You can make a global variable to store what is the last tab
private TabPage LastTab = null;
private void tabSelectionChanged(...)
{
if(LastTab != null)
//Do save
LastTab = tab.SelectedTabPage;// or equivalent
}

Use the below code:
private object LastTab = null;
private void tabSelectionChanged(...)
{
if(LastTab != null)
{
//Do save
}
LastTab = control.SelectedContent;
}
Here the the content will be of type object you can type cast to specific class and do the save operation

What you need exists in the parameter SelectionChangedEventArgs e:
e.AddedItems
e.RemovedItems