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我知道有很多与此相关的问题，我已经阅读了很多。这就是为什么我有这样的代码：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    mWrapperFragment = WrapperFragment.newInstance();

    getSupportFragmentManager()
        .beginTransaction()
        .add(R.id.layout_content, mWrapperFragment, WrapperFragment.TAG)
        .hide(mWrapperFragment)
        .commitNow();
}

@Override
protected void onResume() {
    super.onResume();

    mIsInstanceStateSaved = false;
}

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);

    mIsInstanceStateSaved = true;
}

@Override
public void onWebApplicationReady() {
    if (shouldShowWrapperWebView()) {
        getSupportFragmentManager()
            .beginTransaction()
            .setCustomAnimations(android.R.anim.fade_in, 0)
            .show(mWrapperFragment)
            .commitNow();
    }
}

/**
 * Indicates whether the {@code WrapperFragment} instance should be shown or not.
 * <p>
 * This method will return {@code false} in the following scenarios:
 * <ul>
 * <li>The {@code WrapperFragment} is already visible to the user.</li>
 * <li>The {@link #onSaveInstanceState} method has not yet been called.</li>
 * <li>The activity is not in the process of finishing.</li>
 * </ul>
 *
 * @return {@code true} if the {@code WrapperFragment} can be shown, {@code false} otherwise.
 */
private boolean shouldShowWrapperWebView() {
    return !mWrapperFragment.isVisible() && !mIsInstanceStateSaved && !isFinishing();
}

这里需要注意的重要一点是onWebApplicationReady，将由加载在WebView该WrapperFragment extends WebViewFragment主机上的 Web 应用程序调用的回调。

鉴于我的shouldShowWrapperWebView()，我不明白为什么我仍然会收到这个异常，这会使某些用户的应用程序崩溃：

Fatal Exception: java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
       at android.support.v4.app.FragmentManagerImpl.checkStateLoss(SourceFile:1832)
       at android.support.v4.app.FragmentManagerImpl.ensureExecReady(SourceFile:1954)
       at android.support.v4.app.FragmentManagerImpl.execSingleAction(SourceFile:1965)
       at android.support.v4.app.BackStackRecord.commitNow(SourceFile:614)
       at com.companyname.wrapper.WrapperActivity.showWrapperWebView(SourceFile:336)
       at com.companyname.wrapper.WrapperActivity.onWebApplicationReady(SourceFile:197)
       at com.companyname.wrapper.js.NativeApi$1.run(SourceFile:61)
       at android.os.Handler.handleCallback(Handler.java:739)
       at android.os.Handler.dispatchMessage(Handler.java:95)
       at android.os.Looper.loop(Looper.java:148)
       at android.app.ActivityThread.main(ActivityThread.java:5441)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:738)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:628)
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0 回答 0