My app supports minSdkVersion=10 and targeting 16. I want to call methods specific to API level >= 14 if a specific device supports them. I could check running OS version at runtime and whether call or not higher API methods but when I specify min SDK version, methods that exist only in versions higher than 10 are not visible.
Is there any way to use higher API methods than minSdkVersion?
You can test the device's API with this:
if(android.os.Build.VERSION.SDK_INT >= 14) {
// Do something fancy
}
else {
// Do something regular
}
In addition of checking the current version you should also add #SuppressLint("NewApi")to your method so the compiler want yell about it.
Methods from higher API are invisible and inaccessible because project's target SDK is lower than SDK which methods are going to be used. For example: if you want to use methods from API 14 Android project target SDK should be at least 14 or even better the latest (currently 16). That is kind of obvious but I missed it. After that the solution Sam gave a reference to is in use.
Related
does TargetApi mean that code must be called under a specific version or
must be called greater than or equal specific version?for example
TargetApi(23) means that use for (23 and below ) or (23 and above)?
Target Api 23 means that the annotated method should run only on api 23+ devices. You should use it with IF check for api level of the device. If your app's minimum api level is lower than 23 consider providing a method for older devices.
From TargetApi docs:
Indicates that Lint should treat this type as targeting a given API level, no matter what the project target is.
It's used purely for the linter. Instead of using targetSdkVersion specified in your build.gradle, it will use this API.
When should you use this?
Perhaps when you're using a deprecated API, but you don't want the linter to continue warning you. You explicitly tell the linter, I know that this is deprecated but I don't care, I am using it as if I was on an older API level. You might (should) also add a comment nearby.
If I specify the minimum SDK as 2.0 and the target SDK as 4.1,will I have to write explicit code to ensure backward compatibility. Like if I want to use a gesture detection feature introduced in SDK level 7 and I set the target as 7 and minimum to 3. I am asking will I need to write explicit code(which doesn't include the gesture detection features) so that it runs in targets less than 7 but greater than 3?
Yes, you will have to avoid calling future APIs when running on older versions of Android. You can organize your code to select an appropriate code path at runtime, depending on the version of your OS.
An example of how to preserve backwards-compatibility when using a new API.
Yes, you will need to, but I don't see any logical reason to still support any API before 8 (2.2).
It's literally 1.6% of the market. It's not worth the effort to maintain and support such early versions any more.
That said, if you need to do version specific code, this is the way to handle it:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ECLAIR) {
//Use API 7+ code
} else {
//Use backwards compatible code
}
You should check out the Android official site on how to guarantee backwards compatibility to minimum level 4 (which is negligible up until api level 7 anyway. The slightly more significant share is usually api level 8 upwards), and always use the latest support library.
Of course there are some minor code changes (such as getSupportFragmentManager() in replace of getFragmentManager(),etc). The worst you it can happen is NoSuchMethodException so you have to be real careful not to call API's that does not exist in lower platforms. The sdk should be very clearly advising that when it happens.
Is there any way to detect the current version of android and use one code path for one version, and another code path for a later version?
Something like ClipboardManager, there is a new version in API level 11, but the only way of accessing this new class is by telling mono for android that the minimum requirements is API level 11.
I "think" you can get around this using java reflection, but I imagine this wouldn't work when using Mono for Android. Has anyone got any advice on how you can use both ClipboardManager's, the early one on earlier versions, the later one on later versions, without setting the API level as 11 or higher.
This is a generic example, not limited to ClipboardManager. I am sure I will come across more classes that I could optionally use if it is available.
Sure there is. Just make sure to set your target API level in the manifest.
When wanting to use API 11 for instance you could do something like this:
if ((int)Build.VERSION.SdkInt >= 11)
{
//Execute API 11 and up code here
}
However if you are using methods and classes that are only present in API 11, VS might complain that it cannot find them, so you can surround them with a pre-processor symbol like:
#if __ANDROID_11__
// your API 11 and up code here
#endif
Even though I have done some app on android, I am still confused. Is it possible to use functions in SDK 4.0, and run the app on android 2.1 or lower?
I tried methods you guys mentioned but got an error -
Field requires API level 11 (current min is 7): android.os.AsyncTask#THREAD_POOL_EXECUTOR, if I change min to 11, the app can't install on android 2.1, so even I can use higher API, but it still can't run on android lower version...how to fix that?
From Kzinch's advice, set TargetApi to 11, then it's working!
If you want a program that runs on both SDK4 and SDK 2.1 you have two possibilities. One is to provide alternative implementations on your code when they are needed i.e., if some function from SDK4 is not available in the SDK2.1 then you add a conditional block to your code that check the SDK version and provide code for each branch.
The other possibility is to use the Android Support Libaries in order to use the same code for both SDKs (no conditional blocks required). If you need a function provided by the SDK4 but not for the SDK2.1 you can check if that function is provided by a support library. If it is you can use it and your code will run fine on both SDK4 and SDK2.1 without requiring any version checking. For instance, if you need to use the LruCache class which is available since API level 12 (and so not available on SDK2.1) you can use the v4 support library which provide that function and works on SDK2.1 and SDK4. So in your code you would use
import android.support.v4.util.LruCache;
instead of
import android.util.LruCache;
Yes, you can use functions from the higher API in your code, but you must make sure they are never called on the lower API in runtime.
You should make checks for API level in runtime and provide alternative implementation that exists for that API level.
Let me provide some simple example:
SharedPreferences.Editor edit = PreferenceManager
.getDefaultSharedPreferences(getActivity()).edit();
edit.putInt(KEY, VALUE);
if (Build.VERSION.SDK_INT >= 9) {
edit.apply();
} else {
edit.commit();
}
apply() method is a faster (asynchronous) implementation of commit() method, but it not supported on the API level less than 9. With the help of API version check it all works perfect for all devices.
Update #TargetApi annotaion may be used to suppress Lint warnings/errors for API checks.
it doesn't matter what SDK level you compile your code against. Important is which methods/classes are you calling/instantiating.
If you use any newer classes or methods your code WILL crash running on older devices.
The suggested method to deal with it is Lazy Loading: http://android-developers.blogspot.co.uk/2010/07/how-to-have-your-cupcake-and-eat-it-too.html
and remember, I'm saying this about the SDK.
The compatibility pack is a library developed by google that you can add to any project and use the functions of the library without issues.
Furthermore, there're 3rd party libraries (such as the ActionBar Sherlock http://actionbarsherlock.com/ that aims to bring higher SDK level functionalities to lower SDK levels)
No. You cannot use methods from higher API, because the code to handle it is simply not present on lower version of API. You can, however target as high API version as possible, but you may take care to call these methods on right API. You can easily check that at runtime with. i.e.
f( Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ) {
// code to be run on Honeycomb and higher versions
}
If you are using the API which are specific to higher version, then the app wont work in older version.As those are not defined in the older version it will throw an error.That is the reason we restrict apps before uploading into market using minSDK in AndroidManifest.xml.
My Question: Can I support an older api and use functions of a newer api if available?
My Situation: I'm building a simple app that I want to support some advanced functions with the UI if available. But the API level I'm supporting is 13 so I can support Android 3.2. Specifically, I want to use the View.SYSTEM_UI_FLAG_* variables, but those are not available in api level 13.
Yes, you can check that at runtime:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
// my code using HC API
} else {
// code that works on older API
}
and you have to set android:targetSdkVersion of your app's Manifest to highest API version you want to support, otherwise you will not be able to build it.
Please see this <uses-sdk> related article.