Silverlight：使用UI自动化模拟RadioButton Click事件吗？

Question

In Silverlight, both the Button and the RadioButton controls have a Click event, since they inherit from System.Windows.Controls.Primitives.ButtonBase .

If we want to simulate this Click event for a Button , we can use the ButtonAutomationPeer class, like so (given a button called myButton ):

ButtonAutomationPeer peer = new ButtonAutomationPeer(myButton);
IInvokeProvider ip = (IInvokeProvider)peer;
ip.Invoke();

However, when we try to do the same thing for a RadioButton , we discover that the RadioButtonAutomationPeer class does not implement IInvokeProvider (so we can't call Invoke() ). Is there some other way we can cause the Click event for a RadioButton to be fired?

Answer 1

Try this:

RadioButtonAutomationPeer peer = new RadioButtonAutomationPeer(myRadioButton);
IToggleProvider tp = (IToggleProvider) peer;
while (tp.ToggleState != targetToggleState)
{
   tp.Toggle();
}

You'll need to know your desired toggle state (On, Off, or Indeterminate). Or if you just want to toggle to a different state, strike the while loop just call Toggle.

Obviously this isn't the exact same thing as a click. If you've bound the radio button to a command, you might be forced to be a little more explicit and do something like this to get your automation to work:

<RadioButton ... (don't set the Command property)>
  <i:Interaction.Triggers>
    <i:EventTrigger EventName="Checked">
      <i:InvokeCommandAction Command="{Binding MyCommand}" />
    </i:EventTrigger>
  </i:Interaction.Triggers>
</RadioButton>

Using the Blend SDK (that's the "i:" xmlns), you're invoking a command when the RadioButton is checked. Personally I'd do that approach even without automation over just binding a command to a RadioButton: it's not clear when the command executes with a binding, but the triggers add some clarity and remove the need for me to think the next time I look at the code.