UI Automation not working for DataGridView

Question

After trying out several solutions, I am in desperate need for help.

I tried several approaches, before finally copying and still being stuck with the solution from Getting full contents of a Datagrid using UIAutomation.

Let's talk code, please consider the comments:

// Get Process ID for desired window handle
uint processID = 0;
GetWindowThreadProcessId(hwnd, out processID);

var desktop = AutomationElement.RootElement;

// Find AutomationElement for the App's window
var bw = AutomationElement.RootElement.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ProcessIdProperty, (int)processID));

// Find the DataGridView in question
var datagrid = bw.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.AutomationIdProperty, "dgvControlProperties"));

// Find all rows from the DataGridView
var loginLines = datagrid.FindAll(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.DataItem));

// Badumm Tzzz: loginLines has 0 items, foreach is therefore not executed once 

foreach (AutomationElement loginLine in loginLines)
{
    var loginLinesDetails = loginLine.FindAll(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Custom));

    for (var i = 0; i < loginLinesDetails.Count; i++)
    {
        var cacheRequest = new CacheRequest 
        { 
            AutomationElementMode = AutomationElementMode.None,
            TreeFilter = Automation.RawViewCondition
        };

        cacheRequest.Add(AutomationElement.NameProperty);
        cacheRequest.Add(AutomationElement.AutomationIdProperty);

        cacheRequest.Push();

        var targetText = loginLinesDetails[i].FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ClassNameProperty, "TextBlock"));

        cacheRequest.Pop();

        var myString = targetText.Cached.Name;
    }

}

I can neither fetch a GridPattern, nor a TablePattern instance from datagrid, both results in an exception:

GridPattern gridPattern = null;

try
{
    gridPattern = datagrid.GetCurrentPattern(GridPattern.Pattern) as GridPattern;
}
catch (InvalidOperationException ex)
{
    // It fails!
}

TablePattern tablePattern = null;

try
{
    tablePattern = datagrid.GetCurrentPattern(TablePattern.Pattern) as TablePattern;
}
catch (InvalidOperationException ex)
{
    // It fails!
}

The rows were added to the DataGridView beforehand, like this:

dgvControlProperties.Rows.Add(new object[] { false, "Some Text", "Some other text" });

I am compiling to .Net Framework 4.5. Tried both regular user rights and elevated admin rights for the UI Automation client, both yielded the same results described here.

Why does the DataGridView return 0 rows?

Why can't I get one of the patterns?

Kudos for helping me out!

---

Update:

James help didn't to the trick for me. The following code tough returns all rows (including the headers):

var rows = dataGrid.FindAll(TreeScope.Children, PropertyCondition.TrueCondition);

Header cells can then be identified by their ControlType of ControlType.Header.

Answer 1

The code that you are copying is flawed. I just tested this scenario with an adaptation of this sample program factoring in your code above, and it works.

The key difference is that the code above is using TreeScope.Children to grab the datagrid element. This option only grabs immediate children of the parent, so if your datagrid is nested it's not going to work. Change it to use TreeScope.Descendants, and it should work as expected.

var datagrid = bw.FindFirst(TreeScope.Descendants, new PropertyCondition(AutomationElement.AutomationIdProperty, "dgvControlProperties"));

Here is a link to how the various Treescope options behave. Also, I don't know how your binding the rows to the grid, but I did it like this in my test scenario and it worked flawlessly.

Hopefully this helps.

public class DataObject
{
    public string FieldA { get; set; }
    public string FieldB { get; set; }
    public string FieldC { get; set; }
}

List<DataObject> items = new List<DataObject>();
items.Add(new DataObject() {FieldA="foobar",FieldB="foobar",FieldC="foobar"});
items.Add(new DataObject() { FieldA = "foobar", FieldB = "foobar", FieldC = "foobar" });
items.Add(new DataObject() { FieldA = "foobar", FieldB = "foobar", FieldC = "foobar" });

dg.ItemsSource = items;