WebView加载网页

//添加权限

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

//布局

<WebView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/webview"
    ></WebView>

import android.annotation.SuppressLint;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    private WebView webview;

    @SuppressLint("SetJavaScriptEnabled")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        webview = (WebView) findViewById(R.id.webview);


        WebSettings webSettings = webview.getSettings();
        //设置WebView属性，能够执行Javascript脚本
        webSettings.setJavaScriptEnabled(true);
        //设置可以访问文件
        webSettings.setAllowFileAccess(true);
        //设置支持缩放
        webSettings.setBuiltInZoomControls(true);
        //加载需要显示的网页
        webview.loadUrl("http://www.baidu.com");
        //设置Web视图
        webview.setWebViewClient(new webViewClient ());

    }

    @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;
    }

    @Override
    //设置回退
    //覆盖Activity类的onKeyDown(int keyCoder,KeyEvent event)方法
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if ((keyCode == KeyEvent.KEYCODE_BACK) && webview.canGoBack()) {
            webview.goBack(); //goBack()表示返回WebView的上一页面
            return true;
        }
        finish();//结束退出程序
        return false;
    }
    //Web视图
    private class webViewClient extends WebViewClient {
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }
    }

}

import android.webkit.WebView;
import android.webkit.WebViewClient;



public class webViewClient extends WebViewClient{
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        view.loadUrl(url);
        return true;
    }
}