Question

我正在尝试将webview后退按钮实现到我的应用程序中，因此当用户单击后退按钮时，webview会将其返回到previos页面。但当我按下后退按钮它退出应用程序？这是webview的代码：

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.actionbarsherlock.app.SherlockFragment;
import com.actionbarsherlock.app.SherlockFragmentActivity;
import com.emirnp.next.press.R;

@SuppressLint("SetJavaScriptEnabled")
public class VestiActivity extends SherlockFragmentActivity {

    private static WebView webview;
    private static ProgressBar bar;
    private static String url;

    public static class WebviewFragment extends SherlockFragment {

        @Override
        public void onActivityCreated(Bundle savedInstanceState) {
            super.onActivityCreated(savedInstanceState);
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            try {
                View v = inflater.inflate(R.layout.activity_webview, container,
                        false);
                webview = (WebView) v.findViewById(R.id.webView1);
                webview.setWebChromeClient(new MyWebChromeClient());
                bar = (ProgressBar) v.findViewById(R.id.load);

                url = "http://www.server.se/test/"
                        + getResources().getString(R.string.vesti_id);
                loadUrl();
                return v;
            } catch (Exception e) {
                e.printStackTrace();
            }

            return null;
        }

        private void loadUrl() {

            WebSettings webSettings = webview.getSettings();
            webSettings.setJavaScriptEnabled(true);
            webSettings.setDomStorageEnabled(true);

            final SherlockFragmentActivity activity = getSherlockActivity();
            webview.setWebChromeClient(new WebChromeClient() {
                @Override
                public void onProgressChanged(WebView view, int progress) {
                    if (progress == 100) {
                        bar.setVisibility(View.GONE);
                        webview.setVisibility(View.VISIBLE);
                    }

                }

            });
            webview.setWebViewClient(new WebViewClient() {
                @Override
                public void onReceivedError(WebView view, int errorCode,
                        String description, String failingUrl) {
                    Toast.makeText(activity, description, Toast.LENGTH_SHORT)
                            .show();
                }

            });

            webview.loadUrl(VestiActivity.url);
        }
    }

    @Override
    public void onBackPressed() {
        if (webview.canGoBack())
            webview.goBack();
        else
            super.onBackPressed();
    }
}

WebviewActivity：

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.actionbarsherlock.app.SherlockFragment;
import com.actionbarsherlock.app.SherlockFragmentActivity;
import com.emirnp.next.press.R;

public class WebviewActivity extends SherlockFragmentActivity {

    private static WebView webview;
    private static ProgressBar bar;
    private static String url = null;

    protected static void setUrl(String url) {
        WebviewActivity.url = url;
    }

    public static class WebviewFragment extends SherlockFragment {

        @Override
        public void onActivityCreated(Bundle savedInstanceState) {
            super.onActivityCreated(savedInstanceState);
            // getSherlockActivity().requestWindowFeature(Window.FEATURE_PROGRESS);
            // getSherlockActivity().getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            try {
                View v = inflater.inflate(R.layout.activity_webview, container,
                        false);
                webview = (WebView) v.findViewById(R.id.webView1);
                bar = (ProgressBar) v.findViewById(R.id.load);

                loadUrl();
                return v;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }

        public void loadUrl() {

            WebSettings webSettings = webview.getSettings();
            webSettings.setJavaScriptEnabled(true);
            webSettings.setDomStorageEnabled(true);

            final SherlockFragmentActivity activity = getSherlockActivity();
            webview.setWebChromeClient(new WebChromeClient() {
                @Override
                public void onProgressChanged(WebView view, int progress) {
                    /*
                     * activity.setSupportProgress((Window.PROGRESS_END -
                     * Window.PROGRESS_START) / 100 * progress);
                     */
                    if (progress == 100) {
                        bar.setVisibility(View.GONE);
                        webview.setVisibility(View.VISIBLE);
                    }

                }

            });
            webview.setWebViewClient(new WebViewClient() {
                @Override
                public void onReceivedError(WebView view, int errorCode,
                        String description, String failingUrl) {
                    Toast.makeText(activity, description, Toast.LENGTH_SHORT)
                            .show();
                }
            });

            webview.loadUrl(url);
        }
    }

    @Override
    public void onBackPressed() {
        if (webview.canGoBack())
            webview.goBack();
        else
            super.onBackPressed();
    }

}

activity_webview.xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".AboutActivity" >

    <WebView
        android:id="@+id/webView1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"        
        android:visibility="gone" />

    <ProgressBar
        android:id="@+id/load"
        style="?android:attr/progressBarStyleLarge"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:visibility="visible" />

</RelativeLayout>

Answer 1

你设置onBackPressed，但你必须这样做webView：

`webView.setOnKeyListener( new OnKeyListener()
            {
                @Override
                public boolean onKey( View v, int keyCode, KeyEvent event )
                {
                    if( keyCode == KeyEvent.KEYCODE_BACK && webView.canGoBack())
                    {
                        webView.goBack();
                        return true;
                    }else if( keyCode == KeyEvent.KEYCODE_FORWARD && webView.canGoForward()){
                        webView.goForward();
                        return true;
                    }

                    return false;
                }
            } );`

亲切的问候！

Answer 2

只需将一个WebviewClient对象添加到webview

Webview后退按钮不会返回（退出应用程序）

2 个答案: