android - onSaveInstanceState 不工作

Question

从其他选项卡返回时最后一个链接没有打开而且 onPause() 也不起作用。它显示空指针异常并且应用程序在单击除第一个选项卡之外的其他选项卡时自动关闭。 fragment 标签代码

public class FragmentTab extends Fragment {
    protected WebView myWebView;
    @Override
    public void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_layout, container, false);
        WebView myWebView = (WebView) v.findViewById(R.id.webview);
        WebSettings webSettings = myWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        myWebView.setWebViewClient(new WebViewClient() {
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                view.loadUrl(url);
                return false;
            }
        });
        if(savedInstanceState != null)
            myWebView.restoreState(savedInstanceState);
        else
            myWebView.loadUrl("http://www.example.com");
        return v;
    }
    @Override
public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        myWebView.saveState(outState);
    }
}

这是 MainActivity

public class MainActivity extends FragmentActivity {
    private FragmentTabHost mTabHost;

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

        setContentView(R.layout.activity_main);
        mTabHost = (FragmentTabHost) findViewById(android.R.id.tabhost);
        mTabHost.setup(this, getSupportFragmentManager(), android.R.id.tabcontent);
            mTabHost.addTab(
                    mTabHost.newTabSpec("tab1").setIndicator(null,ContextCompat.getDrawable(this,R.drawable.home)),
                    FragmentTab.class, null);
            mTabHost.addTab(
                    mTabHost.newTabSpec("tab2").setIndicator(null,ContextCompat.getDrawable(this,R.drawable.deals_offers)),
                    FragmentTab.class, null);
            mTabHost.addTab(
                    mTabHost.newTabSpec("tab3").setIndicator(null,ContextCompat.getDrawable(this,R.drawable.profile)),
                    FragmentTab.class, null);
            mTabHost.addTab(
                    mTabHost.newTabSpec("tab4").setIndicator(null, ContextCompat.getDrawable(this, R.drawable.menu)),
                    FragmentTab.class, null);
    }
}

Answer 1

使用这个库:https://github.com/frankiesardo/icepick

从 WebView 中移除保护

@State 
WebView myWebView; // This will be automatically saved and restored

在您的 Activity 方法中添加以下行，Rest 将被处理。

在 OnCreate 方法中

@Override public void onCreate(Bundle savedInstanceState) 
   {
       super.onCreate(savedInstanceState);
       Icepick.restoreInstanceState(this, savedInstanceState);
   }

在onSaveInstanceState中

@Override public void onSaveInstanceState(Bundle outState) 
   {
       super.onSaveInstanceState(outState);
       Icepick.saveInstanceState(this, outState);
   }