如何防止重载Webview页面

时间:2015-04-11 14:04:49

标签: java android android-fragments webview android-studio

我创建了一个应用程序,其中我有3个选项卡,可以使用片段显示网页。每次我从选项卡1切换到选项卡2然后再返回选项卡1,选项卡1将重新加载。我搜索了谷歌和解决方案,我发现它没有工作。到目前为止,我已经尝试过这个:

 @Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
mWebView.saveState(outState);
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mWebView.restoreState(savedInstanceState); 
}

而且:

 <activity ...
      android:launchMode="singleInstance"
    android:alwaysRetainTaskState="true">

这是我的主要活动

import android.annotation.TargetApi;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;

import com.tech.slidechat.adaptor.SlidingTabLayout;
import com.tech.slidechat.adaptor.TabsPagerAdapter;

 @TargetApi(Build.VERSION_CODES.HONEYCOMB)
 public class MainActivity extends ActionBarActivity {
 SlidingTabLayout tabs;
 ViewPager viewPager;
 TabsPagerAdapter adapter;

 Toolbar toolbar;

CharSequence Titles[]={ "tab1", "tab2", "tab3" };
int Numboftabs =3;

@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

     toolbar = (Toolbar) findViewById(R.id.tool_bar);
    setSupportActionBar(toolbar);

    adapter = new TabsPagerAdapter(getSupportFragmentManager(), Titles, Numboftabs);
    // Assigning ViewPager View and setting the adapter
    viewPager = (ViewPager) findViewById(R.id.pager);
    viewPager.setAdapter(adapter);
    // Assiging the Sliding Tab Layout View
    tabs = (SlidingTabLayout) findViewById(R.id.tabs);
    tabs.setDistributeEvenly(true);
    tabs.setCustomTabColorizer(new SlidingTabLayout.TabColorizer() {
        @Override
        public int getIndicatorColor(int position) {
            return getResources().getColor(R.color.tabsScrollColor);
        }

        @Override
        public int getDividerColor(int i) {
            return 0;
        }
    });

    tabs.setViewPager(viewPager);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

这是我的Webview片段之一:

  import android.os.Bundle;
  import android.support.v4.app.Fragment;
  import android.view.KeyEvent;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.webkit.WebChromeClient;
  import android.webkit.WebView;
  import android.webkit.WebViewClient;
  import android.widget.ProgressBar;

  public class GamesFragment extends Fragment {

private ProgressBar progress;


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_games, container, false);

    String url = "http://myurl.com";
    WebView myWebView  = (WebView) rootView.findViewById(R.id.webViewGames);
    myWebView.setWebChromeClient(new myWebViewClient());
    myWebView.getSettings().setJavaScriptEnabled(true);
    progress = (ProgressBar) rootView.findViewById(R.id.progressBar);
    progress.setMax(100);
    myWebView.loadUrl(url);


    myWebView.setWebViewClient(new WebViewClient() {

        @Override
        public boolean shouldOverrideUrlLoading(WebView View, String url) {
            View.loadUrl(url);
            GamesFragment.this.progress.setProgress(0);
            return true;
        }
    });


    myWebView.setOnKeyListener(new android.view.View.OnKeyListener()

    {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {
            if (event.getAction() == KeyEvent.ACTION_DOWN) {
                WebView webView = (WebView) v;

                switch (keyCode) {
                    case KeyEvent.KEYCODE_BACK:
                        if (webView.canGoBack()) {
                            webView.goBack();
                            return true;
                        }
                        break;
                }
            }

            return false;
        }
    });
    return rootView;

}


private class myWebViewClient extends WebChromeClient {
    @Override
    public void onProgressChanged(WebView view, int newProgress) {
        GamesFragment.this.setValue(newProgress);
        super.onProgressChanged(view, newProgress);
    }
}

public void setValue(int progress) {
    this.progress.setProgress(progress);
}


}

一个有趣的事情是,无论何时我使用Tab1和Tab2,它们都没有重新加载但是当我切换到Tab3然后返回到Tab1然后只重新加载。

任何帮助都会深深感激。

1 个答案:

答案 0 :(得分:3)

你能尝试添加:

viewPager.setOffscreenPageLimit(2);

根据文档,setOffscreenPageLimit是:

  

设置应保留在页面两侧的页数   处于空闲状态的视图层次结构中的当前页面。页面超出此范围   在需要时,将从适配器重新创建限制。

     

...

     

您应该保持此限制,特别是如果您的网页具有复杂的&gt;布局。此设置默认为1.

默认值为1,因此当您转到选项卡3时,当前选项卡左侧有两个选项卡,因此将重新创建选项卡1。