Android API and JavaScript call each other

Not to mention, first run the Code. This is the page code we load:

1. How does JavaScript call Android functions:


Webview = new webview (this); webview. getsettings (). setjavascriptenabled (true); webview. addjavascriptinterface (New locationjsobj (this), "android"); webview. addjavascriptinterface (New packagejsobj (this), "package"); webview. loadurl ("file: // android_asset/location.html"); Class locationjsobj {private final context con; Public locationjsobj (context con) {This. con = con;} Public String GPS (string top, string E Nd) {return top + "Degrees:" + 20.5555 + ", degrees:" + 36.4522 + end;} class packagejsobj {private final context mcontext; public packagejsobj (context) {mcontext = context;} Public String ispackageinstall (string pacakgename) {Boolean isinstalled = false; packagemanager PM = mcontext. getpackagemanager (); try {packageinfo = PM. getpackageinfo (pacakgename, 0); If (null! = Packageinfo) {isinstalled = true ;}} catch (namenotfoundexception e) {e. printstacktrace () ;}return pacakgename + "is install:" + isinstalled ;}}


2. the android code calls the functional functions of javascript:


webview = new WebView(this);webview.getSettings().setJavaScriptEnabled(true);webview.loadUrl("file:///android_asset/Location.html");Button button = new Button(this);button.setText("Add new button on web");button.setOnClickListener(mButtOnClickListener);private final OnClickListener mButtOnClickListener = new OnClickListener() {@Overridepublic void onClick(View v) {webview.loadUrl("javascript:addButton()");}};

Complete code after merging:


Package COM. example. javascripttest; import android. app. activity; import android. content. context; import android. content. PM. packageinfo; import android. content. PM. packagemanager; import android. content. PM. packagemanager. namenotfoundexception; import android. OS. bundle; import android. view. view; import android. view. view. onclicklistener; import android. webKit. webview; import android. widget. button; import android. Widget. linearlayout; public class javascripttest extends activity {private webview;/** called when the activity is first created. * // @ overridepublic void oncreate (bundle icicicle) {super. oncreate (icicle); setcontentview (generateconentview ();} private linearlayout generateconentview () {linearlayout = new linearlayout (this); linearlayout. setlayoutparams (New linearlayout. layoutparams (Li Nearlayout. layoutparams. fill_parent, linearlayout. layoutparams. fill_parent); linearlayout. setorientation (linearlayout. vertical); webview = new webview (this); webview. getsettings (). setjavascriptenabled (true); webview. addjavascriptinterface (New locationjsobj (this), "android"); webview. addjavascriptinterface (New packagejsobj (this), "package"); webview. loadurl ("file: // android_asset/location.html"); linearla Yout. layoutparams wvlayoutparams = new linearlayout. layoutparams (linearlayout. layoutparams. fill_parent, linearlayout. layoutparams. wrap_content); wvlayoutparams. weight = 1.0f; webview. setlayoutparams (wvlayoutparams); linearlayout. addview (webview); button = new button (this); button. setlayoutparams (New linearlayout. layoutparams (linearlayout. layoutparams. fill_parent, linearlayout. layoutparams. wrap_con Tent); button. settext ("Add new button on Web"); button. setonclicklistener (mbuttonclicklistener); linearlayout. addview (button); Return linearlayout;} private final onclicklistener mbuttonclicklistener = new onclicklistener () {@ overridepublic void onclick (view v) {webview. loadurl ("javascript: addbutton ()") ;}}; class locationjsobj {private final context con; Public locationjsobj (context con) {This. con = con ;} Public String GPS (string top, string end) {return top + "Degrees:" + 20.5555 + ", degrees:" + 36.4522 + end ;}} class packagejsobj {private final context mcontext; Public packagejsobj (context) {mcontext = context;} Public String ispackageinstall (string pacakgename) {Boolean isinstalled = false; packagemanager PM = mcontext. getpackagemanager (); try {packageinfo = PM. getpackageinfo (pacakgename, 0); If (null! = Packageinfo) {isinstalled = true ;}} catch (namenotfoundexception e) {e. printstacktrace () ;}return pacakgename + "is install:" + isinstalled ;}}}