Android - 優化WebView頁面

WebView包含基礎的HTML顯示功能, 使用時, 需要進行多方面的優化.
(1) 常用設置
(2) 網頁客戶端
(3) 浏覽器客戶端
(4) 滾動條
(5) 獲取網頁內容

Code:

package me.chunyu.Pedometer.base;

import android.annotation.SuppressLint;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.webkit.JavascriptInterface;
import android.webkit.JsResult;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

/**
 * 用於控制WebView的View
 * 由於使用WebView的類型太多，如Activity，Fragment，DialogFragment等
 * 因此將WebView的功能獨立出來作為一個View
 *
 * @author MasaWong
 * @author wangchenlong
 */
@SuppressWarnings({unused, WeakerAccess})
public class PedoWebView extends WebView {

    private static final String TAG = DEBUG-WCL:  + PedoWebView.class.getSimpleName();

    @SuppressWarnings(SpellCheckingInspection)
    private static final String JS_PROCESS_TAG = HTMLOUT; // 用於獲得HTML的內容

    // 用於獲得HTML的內容, 固定格式{@link MyJavaScriptInterface}
    private static final String HTML_CONTENT = javascript：window. + JS_PROCESS_TAG
            + .processHTML('

'+document.getElementsByTagName('html')[0].innerHTML+'');; private ReceivedTitleListener mReceivedTitleListener; private PageFinishedListener mPageFinishedListener; private ReceivedErrorListener mReceivedErrorListener; private UrlLoadingListener mUrlLoadingListener; private JsAlertListener mJsAlertListener; public PedoWebView(Context context) { super(context); if (!isInEditMode()) init(); } public PedoWebView(Context context, AttributeSet attrs) { super(context, attrs, 0); if (!isInEditMode()) init(); } public PedoWebView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); // 資源顯示 if (!isInEditMode()) init(); } /** * 構造函數，配置WebView */ @SuppressLint(AddJavascriptInterface) public void init() { // clearView() is deprecated, but onBackPressed returns to about:blank //noinspection deprecation clearView(); setWebViewClient(); setWebChromeClient(); setWebViewSettings(); setHorizontalScrollBarEnabled(false); // 滾動條不占位 setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY); addJavascriptInterface(new MyJavaScriptInterface(), JS_PROCESS_TAG); } /** * 配置WebView參數 */ @SuppressLint(SetJavaScriptEnabled) protected void setWebViewSettings() { WebSettings settings = getSettings(); // User settings settings.setJavaScriptEnabled(true); // 允許彈窗 settings.setLoadsImagesAutomatically(true); settings.setUseWideViewPort(true); settings.setLoadWithOverviewMode(false); // Technical settings settings.setSupportMultipleWindows(true); // 支持多窗口 settings.setAppCacheEnabled(true); settings.setDatabaseEnabled(true); settings.setDomStorageEnabled(true); // 優先使用緩存 settings.setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK); } /** * 配置WebViewClient來處理網頁加載的各種狀態 */ protected void setWebViewClient() { WebViewClient webClient = new WebViewClient() { // 重定向會加載多次 @Override public void onPageFinished(WebView view, String url) { getSettings().setBlockNetworkImage(false); if (mPageFinishedListener != null) { mPageFinishedListener.overridePageFinished(view, url); } loadUrl(HTML_CONTENT); // 加載JS內容 } @Override public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) { if (mReceivedErrorListener != null) { mReceivedErrorListener.overrideReceivedError(view, errorCode, description, failingUrl); } } @Override public boolean shouldOverrideUrlLoading(WebView view, String url) { return mUrlLoadingListener != null && mUrlLoadingListener.overrideUrlLoading(view, url); } }; setWebViewClient(webClient); } /** * 獲得JS的內容 */ class MyJavaScriptInterface { @JavascriptInterface @SuppressWarnings(unused) public void processHTML(String html) { Log.d(TAG, 咨詢醫生的H5頁面: + html); } } /** * 配置WebChromeClient來處理JsAlert，用於從網頁取得一些復雜的數據 */ protected void setWebChromeClient() { WebChromeClient webChromeClient = new WebChromeClient() { @Override public void onReceivedTitle(WebView view, String title) { if (mReceivedTitleListener != null) { mReceivedTitleListener.onReceivedTitle(view, title); } } @Override public boolean onJsAlert(WebView view, String url, String message, JsResult result) { return mJsAlertListener != null && mJsAlertListener.overrideJsAlert(view, url, message, result); } }; setWebChromeClient(webChromeClient); } /** * 加載Url * * @param url 需要加載的url */ @Override public void loadUrl(String url) { // 把圖片加載放在最後來加載渲染 getSettings().setBlockNetworkImage(true); super.loadUrl(url); } public void setReceivedTitleListener(ReceivedTitleListener receivedTitleListener) { mReceivedTitleListener = receivedTitleListener; } public void setPageFinishedListener(PageFinishedListener pageFinishedListener) { mPageFinishedListener = pageFinishedListener; } public void setReceivedErrorListener(ReceivedErrorListener receivedErrorListener) { mReceivedErrorListener = receivedErrorListener; } public void setUrlLoadingListener(UrlLoadingListener urlLoadingListener) { mUrlLoadingListener = urlLoadingListener; } public void setJsAlertListener(JsAlertListener jsAlertListener) { mJsAlertListener = jsAlertListener; } public interface ReceivedTitleListener { void onReceivedTitle(WebView view, String title); } public interface PageFinishedListener { void overridePageFinished(WebView view, String url); } public interface ReceivedErrorListener { void overrideReceivedError(WebView view, int errorCode, String description, String failingUrl); } public interface UrlLoadingListener { boolean overrideUrlLoading(WebView view, String url); } public interface JsAlertListener { boolean overrideJsAlert(WebView view, String url, String message, JsResult result); } }