WebView
WebView常用方法
public void loadUrl (String url)
//打开本包内asset目录下的test.html文件 loadUrl("file:///android_asset/test.html"); //打开本地sd卡内的kris.html文件 loadUrl("content://com.android.htmlfileprovider/sdcard/malinkang.html"); //打开指定URL的html文件 loadUrl("http://malinkang.com/"); //使用loadUrl调用javascript方法 loadUrl("javascript:test()"); //调用javascript方法传入参数 loadUrl("javascript:test(\"hello\")");有时候html可能需要从资源文件中加载图片
<img src="file:///android_res/drawable/a.png">loadData(String data, String mimeType, String encoding)
loadDataWithBaseURL(String baseUrl, String data, String mimeType, String encoding, String historyUrl)
//加载字符串 4.0+没有问题，2.3下乱码
loadData(htmlStr, "text/html;charset=utf-8",null);
//4.0+和2.3都没有问题
loadDataWithBaseURL(null, htmlStr,"text/html", "utf-8", null);public String getTitle()：获取当前页面的title
WebChromeClient
WebChromeClient是辅助WebView处理Javascript的对话框,网站图标,网站title等。常用方法如下：
public void onProgressChanged(WebView view, int newProgress) {}：告诉应用网页加载进度
WebView源码分析
//WebView的所有操作都是通过调用Provider相应的方法
private WebViewProvider mProvider;
//创建WebViewProvider
private void ensureProviderCreated() {
checkThread();
if (mProvider == null) {
// As this can get called during the base class constructor chain, pass the minimum
// number of dependencies here; the rest are deferred to init().
mProvider = getFactory().createWebView(this, new PrivateAccess());
}
}
//获取WebViewFactoryProvider
@UnsupportedAppUsage
private static WebViewFactoryProvider getFactory() {
//内部通过反射获取WebViewFactoryProvider，不同的版本可能
//创建不同的WebViewFactoryProvider，
return WebViewFactory.getProvider();
}WebViewFactory
//类的路径
private static final String CHROMIUM_WEBVIEW_FACTORY =
"com.android.webview.chromium.WebViewChromiumFactoryProviderForQ";5.0版本的WebView创建的WebViewFactoryProvider对象为WebViewChromiumFactoryProvider。
@Override
public WebViewProvider createWebView(WebView webView, WebView.PrivateAccess privateAccess) {
//创建WebView内核
WebViewChromium wvc = new WebViewChromium(this, webView, privateAccess);
synchronized (mLock) {
if (mWebViewsToStart != null) {
mWebViewsToStart.add(new WeakReference<WebViewChromium>(wvc));
}
}
return wvc;
}@Override
public void addJavascriptInterface(final Object obj, final String interfaceName) {
if (checkNeedsPost()) {
//WebViewChromiumRunQueue
mRunQueue.addTask(new Runnable() {
@Override
public void run() {
addJavascriptInterface(obj, interfaceName);
}
});
return;
}
Class<? extends Annotation> requiredAnnotation = null;
if (mAppTargetSdkVersion >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
requiredAnnotation = JavascriptInterface.class;
}
//AwContents
mAwContents.addPossiblyUnsafeJavascriptInterface(obj, interfaceName, requiredAnnotation);
} /**
* @see ContentViewCore#addPossiblyUnsafeJavascriptInterface(Object, String, Class)
*/
public void addPossiblyUnsafeJavascriptInterface(Object object, String name,
Class<? extends Annotation> requiredAnnotation) {
mContentViewCore.addPossiblyUnsafeJavascriptInterface(object, name, requiredAnnotation);
} */
public void addJavascriptInterface(Object object, String name) {
addPossiblyUnsafeJavascriptInterface(object, name, JavascriptInterface.class);
}
public void addPossiblyUnsafeJavascriptInterface(Object object, String name,
Class<? extends Annotation> requiredAnnotation) {
if (mNativeContentViewCore != 0 && object != null) {
mJavaScriptInterfaces.put(name, new Pair<Object, Class>(object, requiredAnnotation));
//本地方法
nativeAddJavascriptInterface(mNativeContentViewCore, object, name, requiredAnnotation);
}
}更多阅读
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