Question

I am aware that there other questions like this, but their solutions do not work for me.

I have the following code:

     lueSizes.Properties.DataSource = new BindingSource(PS.PaperSizes, null);
     lueSizes.Properties.Columns.Add(new LookUpColumnInfo("PaperName", "Größe"));
     lueSizes.Properties.DisplayMember = "PaperName";
     lueSizes.Properties.ValueMember = "PaperName";

     //PS is a regular System PrinterSettings object
     foreach (PaperSize size in PS.PaperSizes)

         //I confirmed with debugging that this actually happens correctly
         if (size.RawKind == binSettings.SizeRawKind)
          {
              lueSizes.EditValue = size;
              break;
          }

Populating the LookupEdit with the DataSource works fine, the user can select the desired PaperSize from the dropdown, and

lueSizes.GetSelectedDataRow() as PaperSize

then returns a PaperSize object as expected.

The problem I have is setting the EditValue, it simply does nothing. I have verified that at runtime, the DataSource contains all the PaperSize objects in PS.PaperSizes, including the one that is found in the foreach loop. But setting EditValue = size does not cause the selected data row to update accordingly.

Other variations I have tried are:

lueSizes.EditValue = size.PaperName;

lueSizes.EditValue = lueSizes.Properties.GetKeyValueByDisplayText(size.PaperName);

lueSizes.EditValue = lueSizes.Properties.GetKeyValueByDisplayValue(size.PaperName);

lueSizes.EditValue = lueSizes.Properties.GetKeyValueByDisplayValue(size);

lueSizes.EditValue = 0;

None of these do anything, the selected datarow remains NULL and displays nothing to the user.

What else can I try to set the selected DataRow by code?

Edit:

    private void lueSizes_EditValueChanged(object sender, EventArgs e)
    {
        object o = lueSizes.EditValue;
        object p = lueSizes.GetSelectedDataRow();
        PaperSize size = o as PaperSize;
        UpdateSize(size);
    }

Object o is the item I have set earlier, the PaperSize size that Ive found in the loop, but object p is null.

Answer 1

I think I have at least found a workaround:

---

BindingSource bindingSource = new BindingSource(PS.PaperSizes, null);
lueSizes.Properties.DataSource = bindingSource;
lueSizes.Properties.Columns.Add(new LookUpColumnInfo("PaperName", "Größe"));
lueSizes.Properties.DisplayMember = "PaperName";

foreach (PaperSize size in bindingSource)
    if (size.RawKind == BinSettings.SizeRawKind)
    {
        lueSizes.EditValue = size;
        break;
    }

---

private void lueSizes_EditValueChanged(object sender, EventArgs e)
{
    PaperSize size = lueSizes.EditValue as PaperSize;
    Update(size);
}

---

So first, I let the loop search in the BindingSource, which I have to define explicitely now, instead of the Printersettings object.

Next, I may not set the DisplayValue property.

Finally, I avoid looking up the DataRow and go for the edit value directly. Don’t know what limitations

I don’t know what else that breaks, if anything, but for now it works.