CODEWITHSUNDEEP
c#datagridviewcheckedlistbox
roa765
roa765

Reputation: 295

Bind list to DataGridView not displaying anything and wiping out objects every time I click save

I am trying to bind a class list to a DataGridView on my WinForms application. Currently the bind code doesn't do anything. I have debugged through it and the source is correct contains the list with the correct item. But I don't see the rows in the DataGridView.

How do I display whats in the list onto my DataGridView? Also currently every time I click save it clears my class object, however I want to keep the previous values I put in the constructor. If there is already a country that exists I want a user pop up box to state whether they want to over write this or not - is this possible/ how can I best achieve this?

CountryWithDates.cs

 class CountryWithDates
{
    public string country;
    public DateTime firstDate;
    public DateTime furtherDate;
    public DateTime rolldownDate;
    public DateTime endDate;
}

On save click:

  private void Save_Click(object sender, EventArgs e)
    {

        List<CountryWithDates> countryDates = new List<CountryWithDates>();

        for (int i = 0; i < Countries_LB.Items.Count; i++)
        {
            if (Countries_LB.GetItemChecked(i))
            {         
                countryDates.Add(new CountryWithDates(){country = Countries_LB.Items[i].ToString(),
                    firstMarkdownDate = DateTime.Parse(firstDatePicker.Text),
                    furtherMarkdownDate = DateTime.Parse(furtherDatePicker.Text),
                    rolldownMarkdownDate = DateTime.Parse(rolldownDatePicker.Text),
                    endMarkdownDate = DateTime.Parse(endMarkdownPicker.Text)});
            }

        }


//THIS DOESNT DO ANYTHING - I WANT TO BIND THE SOURCE TO THE GRIDVIEW but i dont see the output in the data gridview on the form when i click save
            var bindingList = new BindingList<CountryWithDates>(countryDates);
            var source = new BindingSource(bindingList, null);
            gv_Countries.DataSource = source;

        }

Upvotes: 1

Views: 928

Answers (2)

user10216583
user10216583

Reputation:

You should create public Porperties in your class and not public Fields:

class CountryWithDates
{
    //Following the naming rule is good. I'll leave it to you.
    public string country { get; set; }
    public DateTime firstDate { get; set; }
    public DateTime furtherDate { get; set; }
    public DateTime rolldownDate { get; set; }
    public DateTime endDate { get; set; }

    public CountryWithDates() { }

    public override string ToString()
    {
        return country;
    }
}

This way you can bind a list of CountryWithDates objects to the CheckedListBox:

var lst = new List<CountryWithDates>();

//Add new objects ...
//lst.Add(new CountryWithDates { country = "Country 1", firstDate ... });

checkedListBox1.DataSource = null;
checkedListBox1.DataSource = lst;

To get and update the checked items from the list, create a new BindingSource, and bind it to the DataGridView, you just need to do:

checkedListBox1.CheckedItems
    .Cast<CountryWithDates>()
    .ToList()
    .ForEach(item =>
    {
        item.firstDate = firstDatePicker.Value;
        item.furtherDate = furtherDatePicker.Value;
        item.rolldownDate = rolldownDatePicker.Value;
        item.endDate = endMarkdownPicker.Value;
    });
dataGridView1.DataSource = null;
var bs = new BindingSource(checkedListBox1.CheckedItems.Cast<CountryWithDates>(), null);
dataGridView1.DataSource = bs;

Upvotes: 3

Caius Jard
Caius Jard

Reputation: 74605

If I were doing this I would:

  • Add a new DataSet to my project
  • Open the DataSet designer
  • Add a DataTable, call it CountryWithDates, 6 columns (Country, First, Further, Markdown, End, SaveThisRow(boolean))
  • Save the DataSet
  • Open the form designer
  • Show the datasources window
  • Drag the node representing CountryWithDates onto the designer

DataGridView appears, as does dataset, bindingsource etc. Everything is bound already.

When time comes to save to disk and you only want to save those checked items, datatable.Copy() it, then delete every row that isn't marked for save, then call WriteXml to save the cleaned up copy. Perhaps something like this (untested):

private blah SaveButton_Click(blah){

    var dt = (CountryWithDatesDataTable)_myDataset.CountryWithDates.Copy();
    for(int i = dt.Count - 1; i >= 0; i--){
      if(!dt[i].SaveThisRow)
        dt[i].Delete(); //mark row deleted
    }
    dt.WriteXml(@"C:\temp\dt.xml")

}

Upvotes: 2

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