Android 原生 pdf 预览，pdf.js

1.资源绑定中pdf_js解压后文件夹放入项目assets文件中

2.websetting设置可加载pdf
WebSettings webSettings = webView.getSettings();
webSettings.setAllowFileAccess(true);
webSettings.setAllowContentAccess(true);
webSettings.setAllowUniversalAccessFromFileURLs(true);
webSettings.setAllowUniversalAccessFromFileURLs(true);

3.webview加载url
String url = "file:///android_asset/pdf_js/index.html?" + AppClient.HOST + pdfPath; 
webView.loadUrl(url);