Question

我正在使用ViewPager加载我的FragmentActivity中包含两个webview的相同片段。

在片段中，我在两个不同的webview中加载了两个html文件。有时我可能会使用外部JavaScript来加载webview。

所以，我的问题是，当我第一次尝试打开活动时，它会顺利加载html文件。

完成FragmentActivity并再次打开后，加载相同的html文件需要花费太多时间。

一次又一次打开时持续时间不断增加。

Answer 1

如果修复了html代码，您可以使用来自缓存选项的加载，而不是每次从网络加载。

Answer 2

I am facing the same issue. I am using multiple webviews in a viewpager to show news detail pages and user can swipe between these pages. This activity is loaded when user clicks on a list item. With every subsequent loading, the time taken is increasing. i am sure it has something to do with code but cant really understand what. Code below:

package com.samples.app.activities;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Build;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;

import android.view.Window;
import android.view.WindowManager;
import android.webkit.WebChromeClient;
import android.webkit.WebResourceError;
import android.webkit.WebResourceRequest;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import com.samples.app.R;
import com.samples.app.adapters.NewsDetailWebViewPagerAdapter;
import com.samples.app.utilities.NewsPageConstants;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class NewsDetailWebViewActivity extends AppCompatActivity {

    /**
     * The {@link android.support.v4.view.PagerAdapter} that will provide
     * fragments for each of the sections. We use a
     * {@link FragmentPagerAdapter} derivative, which will keep every
     * loaded fragment in memory. If this becomes too memory intensive, it
     * may be best to switch to a
     * {@link android.support.v4.app.FragmentStatePagerAdapter}.
     */
    private NewsDetailWebViewPagerAdapter mPagerAdapter;

    /**
     * The {@link ViewPager} that will host the section contents.
     */
    private ViewPager mViewPager;
    private List<View> mListWebViews;
    private HashMap<Integer, String> mNewsDetailUrls;

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

        setContentView(R.layout.activity_news_detail_web_view);

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        if(getSupportActionBar() != null){
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        }

        Intent intent = getIntent();
        int selectedPosition = intent.getIntExtra(NewsPageConstants.KEY_SELECTED_POSITION, 0);
        mNewsDetailUrls = getNewsDetailViewUrls();
        initializeViews();

        // Create the adapter that will return a fragment for each of the three
        // primary sections of the activity.
        mPagerAdapter = new NewsDetailWebViewPagerAdapter(mListWebViews, selectedPosition);

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.vp_news_wv_detail);
        mViewPager.setAdapter(mPagerAdapter);
        mViewPager.setCurrentItem(selectedPosition);
    }

    private void initializeViews() {
        mListWebViews = new ArrayList<>();
        for(int i = 0; i < mNewsDetailUrls.size(); i++){
            addView(mListWebViews, mNewsDetailUrls.get(i));
        }
    }

    private HashMap<Integer, String> getNewsDetailViewUrls() {
        return NewsListActivity.news.getNewsLinksMap();
    }

    private List<View> addView(List<View> viewList,String url) {
        final Activity activity = this;
        final ProgressBar progressBar = (ProgressBar) findViewById(R.id.wv_progress);
        WebView webView = new WebView(this);
        //WebView webView = (WebView) findViewById(R.id.wv_news_detail);
        webView.getSettings().setJavaScriptEnabled(true);
        /*if (Build.VERSION.SDK_INT >= 19) {
            webView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
        }
        else {
            webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        }*/
        webView.setWebChromeClient(new WebChromeClient(){
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                super.onProgressChanged(view, newProgress);
                activity.setProgress(newProgress * 100);
            }
        });
        webView.setWebViewClient(new WebViewClient() {
            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                progressBar.setVisibility(View.VISIBLE);
                super.onPageStarted(view, url, favicon);
            }

            @Override
            public void onPageFinished(WebView view, String url) {
                progressBar.setVisibility(View.GONE);
                super.onPageFinished(view, url);
            }

            @Override
            public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
                super.onReceivedError(view, request, error);
                Toast.makeText(activity, "Cannot load page", Toast.LENGTH_SHORT).show();
                progressBar.setVisibility(View.GONE);
            }
        });
        webView.loadUrl(url);
        viewList.add(webView);
        return viewList;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds the language toggle button to the action bar.
        getMenuInflater().inflate(R.menu.menu_news_detail_web_view, menu);

        return true;
    }

    @Override
    public void onBackPressed() {
        super.onBackPressed();
        finish();
    }
}

在ViewPager内的Fragment中缓慢加载WebView中的html文件

2 个答案: