Cordova android emulation - Error: Cannot read pro

问题:

Trying to emulate Android app with cordova, but get this error message:

Built the following apk(s): /Users/jnj/cordova/hello/platforms/android/build/outputs/apk/android-debug.apk ANDROID_HOME=/Users/jnj/Library/Android/sdk JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_151.jdk/Contents/Home

Error: Cannot read property 'semver' of null

Any solutions?

回答1:

This is due using an emulator with an unstable Developer Preview API version.

You probably have a device using API 27 (Android 8.1).

Open your AVD, remove that device and re-run.

It's also useful to use --target <emulator_name> when launching the emulator if you have more than one.

To get a list of available names to use, call the emulate command with --list

回答2:

The Mighty Chris is right, that is the problem and he fixed it upstream (thank you Chris!). However just to add to his answer, for people like me who cannot update cordova-android to include the patch, the fix is (for cordova-android v6.4.0):

• find the path <project_root>/platforms/android/cordova/lib/emulator.js
• find the line avd.target = 'Android ' + level.semver + ' (API level ' + api_level + ')';
• replace it with avd.target = 'Android ' + (level ? level.semver : '') + ' (API level ' + api_level + ')';

Here is the relevant patch.

回答3:

This is a bug in cordova-android's list_images method, it crashes when it encounters an android version on your system that's not in its list: https://github.com/apache/cordova-android/pull/422

You can apply the fix manually in platforms/android/cordova/emulator.js within your project

回答4:

I had a similar problem and what I did was to run adb devices on the terminal to check if my device was prorprly connected or not and I found that my device was not connected properly, I think there was a problem with my USB cable and so I disconnected the cable and connected it again an ran the same command adb devices, then it showed my device as connected. My problem was solved, I hope it'll help someone else.

回答5:

For me, on a Mac, the following was required to get the sdk running in the emulator:

Open Android Studio (and open your project if it doesn't open at start up)

Select 'Tools -> AVD Manager' to open the device manager tool

Right click on the relevant image (or create one if required first)

Select 'Cold Boot Now' and wait for the emulator to boot up

In a terminal cd to the folder where your platforms and config.xml. Where cordova commands can be run

List available devices with adb devices (Install it if it says not available) to get a list of running devices, and grab your EMULATOR ID. For me on this occasion it was emulator-5554.

Run the command cordova run android --target "emulator-5554" replacing emulator-5554 with your own reference.