Trigger a keyboard key press event without pressing the key from keyboard

Question

How can I trigger a key press event without pressing the key from Keyboard? I tried with the solution from here, but I got the following exception:

The best overloaded method match for 'System.Windows.PresentationSource.FromVisual(System.Windows.Media.Visual)' has some invalid arguments.

Consider Shift+A contains 2 key press event from keyboard,how can I do it without keyboard pressing?(let, just print capital A in a textbox on a button click)

My code

var key = Key.A;                    // Key to send
var target = Keyboard.FocusedElement;    // Target element
var routedEvent = Keyboard.KeyDownEvent; // Event to send

target.RaiseEvent(new System.Windows.Input.KeyEventArgs(Keyboard.PrimaryDevice, System.Windows.PresentationSource.FromVisual(target), 0, key) { RoutedEvent = routedEvent });

Solution 1

System.Windows.Forms.SendKeys.Send() has done the trick for me.

For advanced instructions and the list of available codes, consult the docs for the method.

For example, to send Shift+A I used SendKeys.Send("+(a)").

Solution 2

You need to cast to Visual :

var key = Key.A;                    // Key to send
var target = Keyboard.FocusedElement;    // Target element
var routedEvent = Keyboard.KeyDownEvent; // Event to send

target.RaiseEvent(new System.Windows.Input.KeyEventArgs(Keyboard.PrimaryDevice,
 System.Windows.PresentationSource.FromVisual((Visual)target), 0, key) { RoutedEvent = routedEvent });

You could also specify that your target is a specific textbox for example :

var target = textBox1;    // Target element

What the code actually does is trigger the keydown event for a specific element. So it makes sense to have a keydown handler for it :

private void textBox1_KeyDown(object sender, System.Windows.Input.KeyEventArgs e)
{

}

Comments

[ridoy]

But a get a new exception while trying your above code,Value cannot be null.Parameter name: v ...

[ridoy]

I put this code into a button click event(is this a problem?).And the full exception was that what i mentioned.

[Sami Franka]

@ridoy I also have it in a button click, but I'm not using this line var target = Keyboard.FocusedElement; because the focused element would be the button, you need to specify the target as the name of your textbox. e.g : var target = YourTextBox;

[ridoy]

I see,thanks for pointing the error.But i need to do it for any case,not for a single textbox.Assume,i have 10 textboxes in a form,then what should be the criteria?

[Sami Franka]

You can set the button Focusable="False". And you can use var target = Keyboard.FocusedElement; This way the textbox will be focused even if you click the button.

[ridoy]

Thanks for your effort. System.Windows.Forms.SendKeys.Send("A") has done the trick for me :)