webView简易浏览器

package com.dream.myapplication;

import android.app.ProgressDialog;import android.content.Intent;import android.net.Uri;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.KeyEvent;import android.webkit.WebChromeClient;import android.webkit.WebSettings;import android.webkit.WebView;import android.webkit.WebViewClient;import android.widget.Toast;

public class MainActivity extends AppCompatActivity {    private String url = "https://www.baidu.com";    private WebView webView;    private ProgressDialog dialog;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);       // Uri uri = Uri.parse(url);       // Intent intent = new Intent(Intent.ACTION_VIEW,uri);        //startActivity(intent);        init();    }    private void init() {        webView = (WebView) findViewById(R.id.web_view);        webView.loadUrl(url);        //webview中打开网页        webView.setWebViewClient(new WebViewClient() {            @Override            public boolean shouldOverrideUrlLoading(WebView view, String url) {                //返回值为true的时候，控制网页在webView中打开，false调用系统/第三方浏览器                view.loadUrl(url);                return true;            }        });       WebSettings settings = webView.getSettings();        settings.setJavaScriptEnabled(true);        //webview使用缓存加载        settings.setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);        webView.setWebChromeClient(new WebChromeClient() {            @Override            public void onProgressChanged(WebView view, int newProgress) {                if (newProgress == 100) {                    //网页加载完毕，关闭                    closeDialog();                } else {                    //网页加载中，打开Dialog                    openDialog(newProgress);                }            }        });    }    private void openDialog(int newProgress) {        if(dialog==null){            dialog = new ProgressDialog(this);            dialog.setTitle("正在加载");            dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);            dialog.setProgress(newProgress);            dialog.show();        }else{            dialog.setProgress(newProgress);        }    }    private void closeDialog() {        if (dialog != null && dialog.isShowing()) {            dialog.dismiss();            dialog=null;        }    }    //改写物理键返回的逻辑    @Override    public boolean onKeyDown(int keyCode, KeyEvent event) {        if (keyCode==KeyEvent.KEYCODE_BACK){            //Toast.makeText(this,webView.getUrl(),Toast.LENGTH_SHORT).show();            if(webView.canGoBack()){                webView.goBack();                return true;            }else {                System.exit(0);            }        }        return super.onKeyDown(keyCode, event);    }}