Checking if control exists throws an error - coded-ui-tests

Question

Really what I am after is a way to check if the control exists without throwing an error.
The code should look something like this:
Control myControl = UIMap.MyMainWindow;
if (!myControl.Exists)
{
//Do something here
}
The problem is that the control throws an error because it is invalid if it doesn't exist, essentially making the exists property useless.
What is the solution?

Answer 1

In this case I am using the tryfind method.
Like this:
HtmlDiv list = new HtmlDiv(Window.GetWebtop());
list.SearchConfigurations.Add(SearchConfiguration.AlwaysSearch);
list.SearchProperties.Add(HtmlDiv.PropertyNames.InnerText, "Processing search", PropertyExpressionOperator.Contains);
if (list.TryFind())
{
//DO Something
}

Answer 2

I am re-posting the comment kida gave as a answer, because I think its the best solution.
Control myControl = UIMap.MyMainWindow;
if (!myControl.FindMatchingControls().Count == 0)
{
//Do something here
}
The FindMatchingControls().Count is much faster then the Try Catch or the TryFind. Since it does not wait for SearchTimeoutto check if the element is now there. Default it waits 30 seconds for the element to not be there, but I like my tests to fail fast.
Alternatively its possible to lower the Playback.PlaybackSettings.SearchTimeout before the Catch or TryFind and restore it afterwards, but this is unnecessary code if you ask me.

Answer 3

You can do one of two things: Wrap your code in a try-catch block so the exception will be swallowed:
try
{
if (!myControl.Exists)
{
// Do something here.
}
}
catch (System.Exception ex)
{
}
Or, you could add more conditions:
if (!myControl.Exists)
{
// Do something here.
}
else if (myControlExists)
{
// Do something else.
}
else
{
// If the others don't qualify
// (for example, if the object is null), this will be executed.
}
Personally, I like the catch block, because if I expect the control to be there as part of my test, I can Assert.Fail(ex.ToString()); to stop the test right there and log the error message for use in bug reporting.

Answer 4

If you are sure that control will exist or enabled after some time you can use WaitForControlExist() or WaitForControlEnabled() methods with a default timeout or specified timeout.
I have a situation like this and I am looping until the control is available :
bool isSaveButtonExist = uISaveButton.WaitForControlEnabled();
while (!isSaveButtonExist )
{
try
{
uISaveButton.SearchConfigurations.Add(SearchConfiguration.AlwaysSearch);
uISaveButton.SetFocus(); // setting focus for the save button if found
isSaveButtonExist = uISaveButton.WaitForControlExist(100);
}
catch (Exception ex)
{
//Console.WriteLine(ex.Message); // exception for every set focus message if the control not exist
}
}
// do something with found save button
// Click 'Save' button
Mouse.Click(uISaveButton, new Point(31, 37));
please refer to this link for more about these Methods:
Make playback wait methods