WebView混合开发模式二（实现网页的放大，输小等功能）

package com.example.webview_backforward;import android.annotation.SuppressLint;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.webkit.WebView;import android.widget.Button;public class MainActivity extends Activity implements OnClickListener{    private Button buttonback,buttonforward,ZoonmIn,ZoomOut;    private WebView webview;    //private static String URL="http://www.sina.com";    private static String URL="http://www.hao123.com";    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        buttonback=(Button)findViewById(R.id.button1);        buttonforward=(Button)findViewById(R.id.button2);        ZoonmIn=(Button)findViewById(R.id.button3);        ZoomOut=(Button)findViewById(R.id.button4);        webview=(WebView)findViewById(R.id.webView1);        buttonback.setOnClickListener(this);        buttonforward.setOnClickListener(this);        ZoonmIn.setOnClickListener(this);        ZoomOut.setOnClickListener(this);        webview.loadUrl(URL);       // webview.clearView();    }    @SuppressLint("NewApi") @Override    public void onClick(View v) {        switch(v.getId()){        case R.id.button1:            if(webview.canGoBack()){                webview.goBack();            }            break;        case R.id.button2:            if(webview.canGoForward()){                webview.goForward();            }            break;        case R.id.button3:            if(webview.canZoomIn()){                webview.zoomIn();            }            break;        case R.id.button4:            if(webview.canZoomOut()){                webview.zoomOut();            }            break;        }    } }

<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"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >    <Button        android:id="@+id/button1"        style="?android:attr/buttonStyleSmall"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentTop="true"        android:text="后退" />    <Button        android:id="@+id/button2"        style="?android:attr/buttonStyleSmall"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignTop="@+id/button1"        android:layout_toRightOf="@+id/button1"        android:text="前进" />    <Button        android:id="@+id/button3"        style="?android:attr/buttonStyleSmall"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignTop="@+id/button2"        android:layout_toRightOf="@+id/button2"        android:text="放大" />    <Button        android:id="@+id/button4"        style="?android:attr/buttonStyleSmall"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignTop="@+id/button3"        android:layout_toRightOf="@+id/button3"        android:text="输小" />    <WebView        android:id="@+id/webView1"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_alignLeft="@+id/button2"        android:layout_below="@+id/button2"        android:layout_marginLeft="18dp"        android:layout_marginTop="116dp" /></RelativeLayout>

访问网络需要加权限

<uses-permission android:name="android.permission.INTERNET"/>