WebView

<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=".MainActivity" >

<EditText

android:id="@+id/editText1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentTop="true"

android:layout_centerHorizontal="true"

android:layout_marginTop="22dp"

android:hint="请输入网址"

android:ems="10" >

</EditText>

<WebView

android:id="@+id/webview"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_alignParentBottom="true"

android:layout_alignParentLeft="true"

android:layout_below="@+id/button1" />

<Button

android:id="@+id/button1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_below="@+id/editText1"

android:layout_centerHorizontal="true"

android:layout_marginTop="22dp"

android:text="搜索" />

<ProgressBar

android:id="@+id/progressBar1"

style="?android:attr/progressBarStyleHorizontal"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_alignParentRight="true"

android:layout_alignParentTop="true" />

</RelativeLayout>

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

public class MainActivity extends Activity {

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

find();

WebSettings webSettings = webview.getSettings();

// load_default 只要有缓存，就用缓存

// load_cache_else_network 当缓存失效时，加载网络

// LOAD_DEFAULT, LOAD_CACHE_ELSE_NETWORK, LOAD_NO_CACHE or

// LOAD_CACHE_ONLY. The default value is LOAD_DEFAULT.

webSettings.setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);

// 设置是否展示一个缩放的控制器

webSettings.setBuiltInZoomControls(true);

// 最高缩放的级别

webSettings.setDefaultZoom(ZoomDensity.FAR);

// 设置默认的字体大小

webSettings.setDefaultFontSize(20);

// 设置只在当前页面展示

// webview.setWebViewClient(new WebViewClient());

// 设置有关网页加载进度的客户端

webview.setWebChromeClient(new WebChromeClient(){

@Override

public void onProgressChanged(WebView view, int newProgress) {

// TODO Auto-generated method stub

super.onProgressChanged(view, newProgress);

//显示进度条

progressBar1.setVisibility(View.VISIBLE);

progressBar1.setProgress(newProgress);

//当进度==100，隐藏进度条

if(newProgress==100){

progressBar1.setVisibility(View.GONE);

}

}

});

button1.setOnClickListener(new OnClickListener() {

public void onClick(View v) {

String trim = editText1.getText().toString().trim();

webview.loadUrl(trim);

}

});

}

private void find() {

button1=(Button)findViewById(R.id.button1);

editText1=(EditText)findViewById(R.id.editText1);

webview=(WebView)findViewById(R.id.webview);

progressBar1=(ProgressBar)findViewById(R.id.progressBar1);

}

//返回键监听

@Override

public boolean onKeyDown(int keyCode, KeyEvent event) {

if(keyCode==KeyEvent.KEYCODE_BACK){

//如果webview可以后退

if(webview.canGoBack()){

webview.goBack();

}else{

finish();

}

}

return true;

}