Start activity with adb

问题:

I have a simplest possible test app, developed with xamarin, deployed to a usb connected droid. With the goal of having one day a working intent url, I'm trying to call my main activity with adb shell am. Here are the first few lines of my MainActivity...

namespace DematAEAT_Android
{
    [Activity(Label = "DematAEAT_Android", MainLauncher = true, Icon = "@drawable/icon")]
    [IntentFilter(new[] { "AcquireSignedImage" },
        Categories = new[] { Intent.CategoryBrowsable, Intent.CategoryDefault })]
    public class MainActivity : Activity
    {
        int count = 1;

Here are two shell commands. In the first, the package manager successfully understands the package name and reports the apk path. In the second, the activity manager fails to resolve the class MainActivity. It fails with or without the namespace.

C:\Program Files (x86)\Android\android-sdk\platform-tools>adb -d shell pm path "fr.company.DematAEAT_Android"
package:/data/app/fr.company.DematAEAT_Android-1/base.apk

C:\Program Files (x86)\Android\android-sdk\platform-tools>adb -d shell am start -n "fr.company.DematAEAT_Android/.DematAEAT_Android.MainActivity"
Starting: Intent { cmp=fr.company.DematAEAT_Android/.DematAEAT_Android.MainActivity }
Error type 3
Error: Activity class {fr.company.DematAEAT_Android/fr.company.DematAEAT_Android.DematAEAT_Android.MainActivity} does not exist.

edit... And yet, I can launch happily using monkey. The following command works fine. Tis as if there's a problem with the way I'm naming my activity class in the adb shell am call, but I can't spot it.

C:\Program Files (x86)\Android\android-sdk\platform-tools>adb shell monkey -p fr.company.DematAEAT_Android 1
Events injected: 1
## Network stats: elapsed time=170ms (0ms mobile, 0ms wifi, 170ms not connected)

Can anyone tell me how to call this activity?

回答1:

Well who knew? I needed to grub around in my manifest.xml to discover that xamarin is appending a hash as a namespace in front of my activity name. So the adb call that works looks like this...

C:\Program Files (x86)\Android\android-sdk\platform-tools>adb -d shell am start -n fr.company.DematAEAT_Android/md5abda05033ab0415fc7a776c5d9734c74.BrowsableActivity
Starting: Intent { cmp=fr.company.DematAEAT_Android/md5abda05033ab0415fc7a776c5d9734c74.BrowsableActivity }

The story continues here. This will likely be an issue for anyone trying to start a xamarin activity via adb shell am, or trying to start a xamarin activity with an intent, or an intent url.

回答2:

This was a breaking change in Xamarin Android 5.0

Android Callable Wrapper Naming

The name mangling scheme for Android Callable Wrappers is changing. Previously, the Android Callable Wrapper package name was constructed by lowercasing the namespace name, which would result in packaging failures if more than one assembly contained a type with the same fully-qualified name.

With the 5.0 release, the default package names for Android Callable Wrappers will be based on the MD5SUM of the assembly-qualified name of the type being exported. This allows the same fully-qualified name to be provided from two different assemblies and not get a packaging error.

https://developer.xamarin.com/releases/android/xamarin.android_5/xamarin.android_5.1/#Android_Callable_Wrapper_Naming

You can override that for your Activity by specifying the name in the [Activity] attribute:

[Activity(Name = "fr.company.demeat_android.MainActivity")]
public class MainActivity : Activity {
    /* ... */
}