你需要監(jiān)聽(tīng)button的PreviewGotKeyboardFocus事件，在這個(gè)事件處理函數(shù)中拿到Keyboard.FocusedElement并變量保存，然后在button的Click事件中就可以使用該變量了，代碼大概類似如下：

        private IInputElement focusedControl;        private void btn_Click(object sender, RoutedEventArgs e)
        {            if(focusedControl != null && focusedControl is TextBox)
            {
                TextBox tb = (TextBox)focusedControl;
                tb.Text = DateTime.Now.ToString();
            }
        }        private void btn_PreviewGotKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
        {
            focusedControl = Keyboard.FocusedElement;
        }