Android WebView的使用

WebView可以使得网页轻松的内嵌到app里，还可以直接跟js相互调用。

webview有两个方法：setWebChromeClient 和 setWebClient

setWebClient：主要处理解析，渲染网页等浏览器做的事情

setWebChromeClient：辅助WebView处理Javascript的对话框，网站图标，网站title，加载进度等

WebViewClient就是帮助WebView处理各种通知、请求事件的。

使用WebView：可以在代码中和布局中使用。

代码中：创建WebView的实例加入到Activity view tree中

WebView webview = new WebView(this);  
setContentView(webview); 

布局中：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

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

</WebView>

</LinearLayout>

对WebView的设置

        wvShop.loadUrl("http://demo3.tp-shop.cn");
        WebSettings webSettings = wvShop.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setSupportZoom(true);
        wvShop.setWebViewClient(mWebViewClientBase);
        wvShop.setWebChromeClient(mWebChromeClientBase);

         private WebViewClientBase mWebViewClientBase = new WebViewClientBase();

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

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            super.onPageStarted(view, url, favicon);
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);
        }

        @Override
        public void onReceivedError(WebView view, int errorCode,
                                    String description, String failingUrl) {
            super.onReceivedError(view, errorCode, description, failingUrl);
        }

        @Override
        public void doUpdateVisitedHistory(WebView view, String url,
                                           boolean isReload) {
            super.doUpdateVisitedHistory(view, url, isReload);
        }
    }

    private WebChromeClientBase mWebChromeClientBase = new WebChromeClientBase();

    private class WebChromeClientBase extends WebChromeClient {

        @Override
        public void onProgressChanged(WebView view, int newProgress) {
            TpShopActivity.this.setProgress(newProgress * 1000);
        }

        @Override
        public void onReceivedTitle(WebView view, String title) {
            super.onReceivedTitle(view, title);
        }

        @Override
        public void onReceivedTouchIconUrl(WebView view, String url,
                                           boolean precomposed) {
            super.onReceivedTouchIconUrl(view, url, precomposed);
        }

        @Override
        public boolean onCreateWindow(WebView view, boolean isDialog,
                                      boolean isUserGesture, Message resultMsg) {
            return super.onCreateWindow(view, isDialog, isUserGesture, resultMsg);
        }

    }

对返回键的处理：

    @Override
    public void onBackPressed() {
//        super.onBackPressed();
        if (wvShop.canGoBack()){
            wvShop.goBack();
        }else{
            finish();
        }
    }

参考文章：1.http://blog.youkuaiyun.com/yaodong379/article/details/51960451 使用方法详细。
2.http://blog.youkuaiyun.com/typename/article/details/39030091 有对webview方法的介绍。
3.http://zouhuajian01.blog.163.com/blog/static/117698772012111511449668/ 关于WebView的缩放