Cocoa application contains no menu bars, according to AppleScript

问题

I am creating a mac app that needs to start dictation (OSX 10.8) by itself. Because there is no way to initiate dictation "directly" the best way to do this is through the menu bar "Edit"/"Start Dictation" because a user may have different keyboard shortcuts for it.

Here's the simple script my app calls (using an NSAppleScript object):

tell application "System Events"
    tell application process "MyApp"
        tell menu bar 1
            tell menu bar item "Edit"
                tell menu "Edit"
                    click menu item "Start Dictation"
                end tell
            end tell
        end tell
    end tell
end tell

Here are the results (NSLog'd the error from the AppleScript)

Error:-1719 System Events got an error:
Can’t get menu bar 1 of application process "MyApp". Invalid index.

I did a basic test to see what was going on

My App:

tell application "System Events"
    tell application process "MyApp"
        set x to menu bars
        return x
    end tell
end tell

result: <NSAppleEventDescriptor: [ ]>

Finder:

tell application "System Events"
    tell application process "Finder"
        set x to menu bars
        return x
    end tell
end tell

result: <NSAppleEventDescriptor: [ 'obj '{ 'form':'indx', 'want':'mbar', 'seld':1, 'from':'obj '{ 'form':'name', 'want':'pcap', 'seld':'utxt'("Finder"), 'from':null() } } ]>

So basically AppleScript is telling me my app has no menu bars? I run Accessibility Inspector and sure enough there is in fact a menu bar (plus I can see it...).

What's going wrong here?

回答1:

I was after something similar, I wanted to activate a service from within Emacs which had otherwise overridden the global keyboard shortcut to the service - A different question which I will ask in another thread.

Running your examples above I did discover that I had to have added the application (Emacs and for testing Automator) to the Accessibility applications (System Preferences -> Security & Privacy -> Privacy -> Accessibility). Further information regarding that on select-a-menu-item-in-applescript-without-using-system-events-in-10-9-maverick and also AppleScript - uiscripting.

With that access in place I am able to see the menu items under services:

tell application "Emacs"
    activate
end tell
tell application "System Events"
    tell application process "Emacs"
        tell menu bar 1
            tell menu "Emacs"       
                tell menu item "Services"
                    tell menu "Services"
                        set x to menu items
                        click menu item "XXX"
                        return x
                    end tell
                end tell
            end tell
        end tell
    end tell
end tell

But the action is not activated!

Using the example above an error is returned that 'XXX' does not exist. Replacing the string with the correct string means no error occurs, but the action does not take place.

回答2:

Have you tried activating your app with a short delay before running the system events stuff? You're also missing some other stuff. Here's how you would do it in Safari...

tell application "Safari" to activate
delay 1

tell application "System Events"
    tell process "Safari"
        tell menu bar item "Edit" of menu bar 1
            click
            delay 0.5
            tell menu item "Speech" of menu 1
                click
                delay 0.5
                click menu item "Start Speaking" of menu 1
            end tell
        end tell

    end tell
end tell

A second point. If you are creating the application yourself then you do not need to do as you are suggesting. You state "Because there is no way to initiate dictation directly" but why do you say that? Every menu item is hooked up to a command, so in essence you can hook into that command if this is your own application. Just create a button or something in your interface and connect it to the same command that the menu item is connected to. For example I can see in Xcode that the "Start Speaking" menu item is connected to First Responder's startSpeaking command. As such you can create a button or some other item and connect it to startSpeaking of First Responder in Interface builder yourself.

来源：https://stackoverflow.com/questions/17007846/cocoa-application-contains-no-menu-bars-according-to-applescript