Android WebView JavaScript interaction

Today, WebView with JavaScript in Android, the first is to add WebView controls to the layout file:

[HTML]View Plaincopy

1. <WebView
2. android:id="@+id/webview"
3. android:layout_width="fill_parent"
4. android:layout_height="fill_parent" />

Then add the permissions in the manifest:

[HTML]View Plaincopy

1. <uses-permission android:name= " and

If WebView can interact with JavaScript, you first need to WebView to enable javascript:

[HTML]View Plaincopy

1. WebSettings websettings = mywebview.getsettings ();
2. Websettings.setjavascriptenabled (TRUE);

Then create the JavaScript interface:

[Java]View Plaincopy

2. Public class Webappinterface {
4. Context Mcontext;
8. /** instantiate the interface and set the context * /
10. Webappinterface (Context c) {
12. Mcontext = C;
14. }
18. /** Show A toast from the Web page * /
20. @JavascriptInterface
22. public void Showtoast (String toast) {
24. Toast.maketext (Mcontext, Toast, Toast.length_short). Show ();
26. }
28. }

To add a JavaScript interface to WebView:

[HTML]View Plaincopy

1. Mywebview.addjavascriptinterface (New Webappinterface (This), "Android");

Local JavaScript files:

[JavaScript]View Plaincopy

1. <input type="button" value="Say Hello" onclick="showandroidtoast (' Hello android! ')"/>
3. <script type="Text/javascript" >
4. function Showandroidtoast (toast) {
5. Android.showtoast (toast);
6. }
7. </script>

The entire code is as follows:

[Java]View Plaincopy

2. Public class Mainactivity extends Activity {
4. private WebView Mywebview;
8. @Override
10. protected void OnCreate (Bundle savedinstancestate) {
12. super.oncreate (savedinstancestate);
14. Setcontentview (R.layout.activity_main);
16. Mywebview = (WebView) Findviewbyid (R.id.webview);
18. WebSettings websettings = Mywebview.getsettings ();
20. Websettings.setjavascriptenabled (true);
22. Mywebview.addjavascriptinterface (new Webappinterface (this), "Android");
24. Processwebstring ();
28. }
32. public class Webappinterface {
34. Context Mcontext;
38. /** instantiate the interface and set the context * /
40. Webappinterface (Context c) {
42. Mcontext = C;
44. }
48. /** Show A toast from the Web page * /
50. @JavascriptInterface
52. public void Showtoast (String toast) {
54. Toast.maketext (Mcontext, Toast, Toast.length_short). Show ();
56. }
58. }
62. private void processwebstring () {
64. //Load Asset file
66. String TPL = getfromassets ("web_tpl.html");
68. Mywebview.loaddatawithbaseurl (null, TPL, "text/html", "Utf-8", null);
70. }
74. /* 
76. * Get HTML files
78. */
80. Public string Getfromassets (String fileName) {
82. try {
84. InputStreamReader Inputreader = new InputStreamReader (
86. Getresources (). Getassets (). open (FileName);
88. BufferedReader Bufreader = new BufferedReader (Inputreader);
90. String line = "";
92. String Result = "";
94. While (line = Bufreader.readline ()) = null)
96. Result + = line;
98. return Result;
100. } catch (Exception e) {
102. E.printstacktrace ();
104. }
106. return "";
108. }
112. }

Operating effect:

Android WebView JavaScript interaction