我最终创建了一个基本片段，并使我的应用程序中的所有片段扩展它

public class BaseFragment extends Fragment {

    private boolean mStateSaved;

    @CallSuper
    @Override
    public void onSaveInstanceState(Bundle outState) {
        mStateSaved = true;
        super.onSaveInstanceState(outState);
    }

    /**
     * Version of {@link #show(FragmentManager, String)} that no-ops when an IllegalStateException
     * would otherwise occur.
     */
    public void showAllowingStateLoss(FragmentManager manager, String tag) {
        // API 26 added this convenient method
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            if (manager.isStateSaved()) {
                return;
            }
        }

        if (mStateSaved) {
            return;
        }

        show(manager, tag);
    }
}

然后，当我试图显示一个片段时，我使用showAllowingStateLoss而不是show

是这样的:

MyFragment.newInstance()
.showAllowingStateLoss(getFragmentManager(), MY_FRAGMENT.TAG);

我从这个PR上找到了这个解决方案:https://github.com/googlesamples/easypermissions/pull/170/files

如果你继承FragmentActivity，你必须调用onActivityResult()中的超类:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    super.onActivityResult(requestCode, resultCode, intent);
    ...
}

如果你不这样做，并试图在该方法中显示一个片段对话框，你可能会得到OP的IllegalStateException。(说实话，我不太明白为什么超级调用可以解决这个问题。onActivityResult()在onResume()之前被调用，所以它仍然不允许显示片段对话框。

不要使用commitAllowingStateLoss()，它只应该用于用户的UI状态可以意外改变的情况。

https://developer.android.com/reference/android/app/FragmentTransaction.html commitAllowingStateLoss ()

如果事务发生在parentFragment的ChildFragmentManager中，则使用 在外面检查parentFragment.isResume()。

if (parentFragment.isResume()) {
    DummyFragment dummyFragment = DummyFragment.newInstance();
    transaction = childFragmentManager.BeginTransaction();
    trans.Replace(Resource.Id.fragmentContainer, startFragment);
}

异常在这里抛出(在FragmentActivity中):

@Override
public void onBackPressed() {
    if (!mFragments.getSupportFragmentManager().popBackStackImmediate()) {
        super.onBackPressed();
    }
}

在FragmentManager.popBackStatckImmediate()中，FragmentManager.checkStateLoss()首先被调用。这就是IllegalStateException的原因。参见下面的实现:

private void checkStateLoss() {
    if (mStateSaved) { // Boom!
        throw new IllegalStateException(
                "Can not perform this action after onSaveInstanceState");
    }
    if (mNoTransactionsBecause != null) {
        throw new IllegalStateException(
                "Can not perform this action inside of " + mNoTransactionsBecause);
    }
}

我通过使用一个标志来标记Activity的当前状态来解决这个问题。以下是我的解决方案:

public class MainActivity extends AppCompatActivity {
    /**
     * A flag that marks whether current Activity has saved its instance state
     */
    private boolean mHasSaveInstanceState;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        mHasSaveInstanceState = true;
        super.onSaveInstanceState(outState);
    }

    @Override
    protected void onResume() {
        super.onResume();
        mHasSaveInstanceState = false;
    }

    @Override
    public void onBackPressed() {
        if (!mHasSaveInstanceState) {
            // avoid FragmentManager.checkStateLoss()'s throwing IllegalStateException
            super.onBackPressed();
        }
    }
}

我最终创建了一个基本片段，并使我的应用程序中的所有片段扩展它

public class BaseFragment extends Fragment {

    private boolean mStateSaved;

    @CallSuper
    @Override
    public void onSaveInstanceState(Bundle outState) {
        mStateSaved = true;
        super.onSaveInstanceState(outState);
    }

    /**
     * Version of {@link #show(FragmentManager, String)} that no-ops when an IllegalStateException
     * would otherwise occur.
     */
    public void showAllowingStateLoss(FragmentManager manager, String tag) {
        // API 26 added this convenient method
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            if (manager.isStateSaved()) {
                return;
            }
        }

        if (mStateSaved) {
            return;
        }

        show(manager, tag);
    }
}

然后，当我试图显示一个片段时，我使用showAllowingStateLoss而不是show

是这样的:

MyFragment.newInstance()
.showAllowingStateLoss(getFragmentManager(), MY_FRAGMENT.TAG);

我从这个PR上找到了这个解决方案:https://github.com/googlesamples/easypermissions/pull/170/files

我得到这个异常时，我按下后退按钮取消意图选择器在我的地图片段活动。 我通过替换onResume(在那里我初始化片段)的代码来解决这个问题，onstart()和应用程序工作正常。希望能有所帮助。