如何逐个连续加载URL

Question

我想逐个加载URL.我使用String数组来存储URL.我的要求是,如果webview加载第一个url,它应该在页面启动时打印msg"page started",当页面finshes它应该显示"页面完成".第一个url加载完成后,它应该加载第二个URL并继续相同的过程.

我写的编码如下:

package com.browser;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.util.Log;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class browser extends Activity {

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        final String[] url={"http://www.yahoo.com","http://www.google.com","http://www.ibnlive.com"};
        final MyWebView mwv = new MyWebView(this); 
        mwv.setWebViewClient(new myweb()); 
        new Thread(new Runnable(){
            public void run(){
                Log.d("runThread","runthread");
                for(int i=0;i<2;i++){
                    openbrowser(url[i]);
                }

            }

            private void openbrowser(String url) {

                mwv.getSettings().setJavaScriptEnabled(true); 
                mwv.loadUrl(url);   
                Log.d("",""+url);
                setContentView(mwv);
            }
        }).start();
    }


    public class MyWebView extends WebView{

        public MyWebView(Context context) {
            super(context);

        }
    }
    public class myweb extends WebViewClient{
        @Override       
        public boolean shouldOverrideUrlLoading(WebView view, String url) { 
            System.out.println("LOADING");

            return false;
        }
        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {

            System.out.println("PageStarted: " + url);
        }

        @Override   
        public void onPageFinished(WebView view, String url){
            System.out.println("PageFinished: " + url);
        }
    }


    }
    ///indented code <--remove this

它只加载最后一个URL.

Answer 1

您可以使用以下代码在webview中逐个加载URL.此代码只是逐个加载您只能看到或不能看到所有网址的网址,但您可以看到最后一个网址.

public class WebViewsScreenActivity extends Activity {

    private WebView mwebview;
    int i =0;
    private WebViewsScreenActivity _activity;
    ProgressDialog _dilog;
    private String[] Urls = {"http://www.google.com","http://www.gmail.com","http://www.yahoo.com"}; 

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);  
         getWindow().requestFeature(Window.FEATURE_PROGRESS);  
        mwebview = new WebView(this);
        setContentView(mwebview);
        _activity = this;  
        mwebview.getSettings().setJavaScriptEnabled(true);
        mwebview.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);

        if(checkInternetConnection(_activity)){
            if(savedInstanceState==null)    
                mwebview.loadUrl(Urls[i]);
            else
                mwebview.restoreState(savedInstanceState);
        }
        else{
            //showAlert  "Unable to Connect Server"
        }
         mwebview.setWebChromeClient(new WebChromeClient() {

                @Override
       public void onProgressChanged(WebView view, int progress) {
                 if(mwebview.getVisibility()==View.VISIBLE)
                 {
                 WebViewsScreenActivity.this.setProgress(progress * 100);

                 }
                }
              });
        mwebview.setWebViewClient(new HelloWebViewClient());
    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        if(keyCode == KeyEvent.KEYCODE_BACK)
        {
            mwebview.goBack();
            return true;
        }
        else
            return super.onKeyUp(keyCode, event);
    }


    //To check whether network connection is available on device or not
    private boolean checkInternetConnection(Activity _activity) {
        ConnectivityManager conMgr = (ConnectivityManager) _activity.getSystemService(Context.CONNECTIVITY_SERVICE);
        if (conMgr.getActiveNetworkInfo() != null
                && conMgr.getActiveNetworkInfo().isAvailable()
                && conMgr.getActiveNetworkInfo().isConnected())
            return true;
        else
            return false;
    }//checkInternetConnection()



    //HelloWebViewClient class for webview
    private class HelloWebViewClient extends WebViewClient {

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            // TODO Auto-generated method stub
            super.onPageStarted(view, url, favicon);
                    Toast.makeText(getApplicationContext(), "Loading started...!"+Urls[i], Toast.LENGTH_SHORT).show();

        }
        @Override
        public void onReceivedError(WebView view, int errorCode,
                String description, String failingUrl) {
            // TODO Auto-generated method stub
            super.onReceivedError(view, errorCode, description, failingUrl);

        }
        @Override
        public void onPageFinished(WebView view, String url) {
            // TODO Auto-generated method stub
            super.onPageFinished(view, url);
                    Toast.makeText(getApplicationContext(), "Loading done...!"+Urls[i], Toast.LENGTH_SHORT).show();
            i++;
            if(i<Urls.length)
                view.loadUrl(Urls[i]);
        }
    } //HelloWebViewClient-class
}//AccountsScreenActivity-class

在manifestast文件中添加权限如下::

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.vl.agarwal"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="8" />
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".WebViewsScreenActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Answer 2

试试这个......

int position=0;

textview.setText("page started");
browser.loadUrl("your first url");
browser.setWebChromeClient(new WebChromeClient()
{
    public void onProgressChanged(WebView view, int progress) 
    {
       if(progress == 100)
       {
          textview.setText("page finished");
          if(position==0)
          {
            browser.loadUrl("your second url");
            position=1;
            textview.setText("page started");
          } 
          if(position==1)
          {
            browser.loadUrl("your third url");
            position=2;
            textview.setText("page started");
          } 
       }
    }
});

你也可以显示Toast而不是TextView ..

Answer 3

问题是您不等待 onPageStarted() 和 onPageFinished 返回任何内容。相反，您的代码只是一一加载网址，速度如此之快，以至于您只能看到最后一个。

您需要修改 for() 循环，以等待 onPagefinished() 方法返回，然后再加载另一个页面。