<Window.Resources>

        <RoutedUICommand x:Key="F3" Text="查找内容"/>

        <RoutedUICommand x:Key="Search" Text="查找内容"/>

    </Window.Resources>

<Window.InputBindings>

    <KeyBinding Gesture="F3" Command="{StaticResource Search}" />

    <KeyBinding Gesture="Ctrl+F" Command="{StaticResource Search}"/>

</Window.InputBindings>

<Window.CommandBindings>

    <CommandBinding Command="{StaticResource Search}" Executed="CommandBindingSearch_Executed"/>

    <CommandBinding Command="{StaticResource F3}" Executed="CommandBindingSearch_Executed"/>

</Window.CommandBindings>

 <MenuItem Header="查找" InputGestureText="Ctrl+F" Click="CommandBindingSearch_Executed" />

private void CommandBindingSearch_Executed(object sender, ExecutedRoutedEventArgs e)

{

    //执行查找

}