Android网页浏览器的开发

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
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" > <LinearLayout
android:layout_width="fill_parent"
android:layout_height="40dp"
android:gravity="center" > <Button
android:id="@+id/btnEar"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="<<" /> <Button
android:id="@+id/btnPre"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="<" /> <Button
android:id="@+id/btnNext"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text=">" /> <Button
android:id="@+id/btnLast"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text=">>" /> </LinearLayout> <LinearLayout
android:layout_width="fill_parent"
android:layout_height="40dp" > <EditText
android:id="@+id/edtUrl"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="5"
android:ems="10"
android:singleLine="true" > <requestFocus />
</EditText> <Button
android:id="@+id/btnGo"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:text="GO" /> </LinearLayout> <WebView
android:id="@+id/webMain"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1" /></LinearLayout>

package com.hzhi.mybrowser;import android.os.Bundle;
import android.app.Activity;
import android.graphics.Bitmap;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;
import android.widget.EditText;public class MainActivity extends Activity implements OnClickListener{// 控件
Button btnEar;
Button btnPre;
Button btnNext;
Button btnLast;
EditText edtUrl;
Button btnGo;
WebView webMain;// URL
String strUrl;@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 获得控件
getCon();
webMain.setWebViewClient(new MyWebViewClient());
}@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}// 获得控件
public void getCon(){
btnEar = (Button) findViewById(R.id.btnEar);
btnPre = (Button) findViewById(R.id.btnPre);
btnNext = (Button) findViewById(R.id.btnNext);
btnLast = (Button) findViewById(R.id.btnLast);
edtUrl = (EditText) findViewById(R.id.edtUrl);
btnGo = (Button) findViewById(R.id.btnGo);
webMain = (WebView) findViewById(R.id.webMain);btnEar.setOnClickListener(this);
btnPre.setOnClickListener(this);
btnNext.setOnClickListener(this);
btnLast.setOnClickListener(this);
edtUrl.setOnClickListener(this);
btnGo.setOnClickListener(this);// 设置JavaScript可用
webMain.getSettings().setJavaScriptEnabled(true);
webMain.setScrollBarStyle(View.SCROLLBAR_POSITION_DEFAULT);
}@Override
public void onClick(View v) {
if (v==btnEar)
{
if (webMain.canGoBackOrForward(-2)){
webMain.goBackOrForward(-2);
}
}
else if (v==btnPre)
{
if (webMain.canGoBack()){
webMain.goBack();
}
}
else if (v==btnNext)
{
if (webMain.canGoForward()){
webMain.goForward();
}
}
else if (v==btnLast)
{
if (webMain.canGoBackOrForward(2)){
webMain.goBackOrForward(2);
}
}
else if (v==edtUrl)
{}
// 下载网页
else if (v==btnGo)
{
strUrl = edtUrl.getText().toString();
webMain.loadUrl("http://" + strUrl);
}
}// WebViewClient的处理类
class MyWebViewClient extends WebViewClient {
@Override
public void doUpdateVisitedHistory(WebView view, String url, boolean isReload) {
btnPre.setEnabled(webMain.canGoBack());
btnNext.setEnabled(webMain.canGoForward());
}
@Override
public void onPageFinished(WebView view, String url) {
if (webMain.getTitle() != null) {
MainActivity.this.setTitle(webMain.getTitle());
}
}
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
MainActivity.this.setTitle(url);
edtUrl.setText(url);
btnPre.setEnabled(webMain.canGoBack());
btnNext.setEnabled(webMain.canGoForward());
}
}}