Incorrect variable names in overridden methods

问题:

When I let Android Studio generate override method it will generate the method with strange parameter names.

For instance according to documentation onCheckedChanged should look like this:

public void onCheckedChanged(CompoundButton buttonView, boolean isChecked){}

but i got

public void onCheckedChanged(CompoundButton compoundButton, boolean b){}

or onDateSet in DatePickerDialog i got:

onDateSet(DatePicker datePicker, int i, int i1, int i2)

instead of

onDateSet(DatePicker view, int year, int month, int dayOfMonth)

I got Android SDK set up in a project and Sources for Android 27 installed.

Any ideas?

Thanks

回答1:

It is related to the compileSdkVersion which is defined in your build.gradle file. You should install Sources for Android SDK for the API you used as compileSdkVersion. So try to install sources version equal to compileSdkVersion in SDK Manager.

I've set the compileSdkVersion 28 in build.gradle file. Here is the result before and after installing sources version 28 (Notice: You should restart AndroidStudio after that):

Before:

val textWatcher = object: TextWatcher {

    override fun afterTextChanged(p0: Editable?) {
    }

    override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
    }

    override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
    }
}

After:

val textWatcher = object: TextWatcher {

    override fun afterTextChanged(s: Editable?) {
    }

    override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
    }

    override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
    }
}

---

UPDATE: 10/23/2018

The problem about AppCompat-v28 libraries such as RecyclerView class, comes from their aar artifacts. If you use version 27.1.1 libraries, the issue will gone. It doesn't matter what distribution of version 28 you are using (Such as 28.0.0, 28.0.0-alpha1, 28.0.0-alpha3, 28.0.0-rc1, 28.0.0-rc2, etc.) In all of version 28 distributions, the parameter names for abstract methods are obfuscated.

public abstract static class Adapter<VH extends RecyclerView.ViewHolder> {

    public Adapter() {
    }

    @NonNull
    public abstract VH onCreateViewHolder(@NonNull ViewGroup var1, int var2);

    public abstract void onBindViewHolder(@NonNull VH var1, int var2);

    ...
}

So it seems that there is no way to solve, until it would be fixed in the next distributions.

回答2:

As aminography said, this is because you have not installed sources for compileSdk you are using. For installing sources follow this steps:

1. check your project's compileSdk version.(from app level build.gradle file). As you can see in below image my compileSdk version is 26. So, i have to install sources for platform 26.

2. Go to sdk manager and in SDK Platforms tab check show package details option if not checked. Then install sources for your compileSdk version(In my case it's 26). That's it. Now, you will get appropriate parameters name.