Android項目中的assert文件下的html裡的js交互

要是webview能夠與JavaScript交互，首先需要webview要啟用JavaScript：

1. WebSettings webSettings = myWebView.getSettings();
2. webSettings.setJavaScriptEnabled(true); 然後創建JavaScript的接口：
   
   1. public class WebAppInterface {
   2. Context mContext;
   4. /** Instantiate the interface and set the context */
   5. WebAppInterface(Context c) {
   6. mContext = c;
   7. }
   9. /** Show a toast from the web page */
   10. @JavascriptInterface
   11. public void showToast(String toast) {
   12. Toast.makeText(mContext, toast, Toast.LENGTH_SHORT).show();
   13. }
   14. }

       給webview添加JavaScript接口：

       [html] view plaincopy
       1. myWebView.addJavascriptInterface(new WebAppInterface(this), "Android");

          本地JavaScript文件：

          [javascript] view plaincopy
          3. <script type="text/javascript">
          4. function showAndroidToast(toast) {
          5. Android.showToast(toast);
          6. }
          7. </script>

             整個代碼如下：

             [java] view plaincopy
             1. public class MainActivity extends Activity {
             2. private WebView myWebView;
             4. @Override
             5. protected void onCreate(Bundle savedInstanceState) {
             6. super.onCreate(savedInstanceState);
             7. setContentView(R.layout.activity_main);
             8. myWebView = (WebView) findViewById(R.id.webview);
             9. WebSettings webSettings = myWebView.getSettings();
             10. webSettings.setJavaScriptEnabled(true);
             11. myWebView.addJavascriptInterface(new WebAppInterface(this), "Android");
             12. ProcessWebString();
             14. }
             16. public class WebAppInterface {
             17. Context mContext;
             19. /** Instantiate the interface and set the context */
             20. WebAppInterface(Context c) {
             21. mContext = c;
             22. }
             24. /** Show a toast from the web page */
             25. @JavascriptInterface
             26. public void showToast(String toast) {
             27. Toast.makeText(mContext, toast, Toast.LENGTH_SHORT).show();
             28. }
             29. }
             31. private void ProcessWebString() {
             32. // 加載 asset 文件
             33. String tpl = getFromAssets("web_tpl.html");
             34. myWebView.loadDataWithBaseURL(null, tpl, "text/html", "utf-8", null);
             35. }
             37. /*
             38. * 獲取html文件
             39. */
             40. public String getFromAssets(String fileName) {
             41. try {
             42. InputStreamReader inputReader = new InputStreamReader(
             43. getResources().getAssets().open(fileName));
             44. BufferedReader bufReader = new BufferedReader(inputReader);
             45. String line = "";
             46. String Result = "";
             47. while ((line = bufReader.readLine()) != null)
             48. Result += line;
             49. return Result;
             50. } catch (Exception e) {
             51. e.printStackTrace();
             52. }
             53. return "";
             54. }
             56. } 這裡獲取到的是assert文件下的html字符串，寫了一個方法獲取assert文件下html

                 
                 

                 還有種方法可以直接load

                 webView.loadUrl("file:///android_asset/html/company.html");
                 

                 assets文件下的html文件下的company.html文件

                 
                 

                 webView.setWebChromeClient(new MyWebClient());
                 

                 private class MyWebClient extends WebChromeClient {
                 
                 
                 @Override
                 public boolean onJsAlert(WebView view, String url, String message,
                 JsResult result) {
                 // TODO Auto-generated method stub
                 Intent intent = null;
                 if (message.contains("tid")) {
                 Pattern pattern = Pattern.compile("tid=(\\d+)");
                 Matcher matcher = pattern.matcher(message);
                 String tid = "";
                 while (matcher.find()) {
                 String st = matcher.group(0);
                 tid = st.split("=")[1];
                 System.out.println("---" + tid);
                 }
                 intent = new Intent(BbsMyHomeActivity.this,
                 BbsHomeDetailTestActivity.class);
                 intent.putExtra("tid", tid);
                 } else {
                 intent = new Intent(BbsMyHomeActivity.this,
                 MyAttentionDetailActivity.class);
                 intent.putExtra("uid", message);
                 }
                 startActivity(intent);
                 // new CustomeToast(BbsMyHomeActivity.this, message);
                 new PopupToast(BbsMyHomeActivity.this, message, footlayout);
                 // 少寫了這行代碼可能會導致，點擊了一次js裡的alert彈出方法，無法點擊第二次。
                 result.cancel();
                 return true;
                 }
                 }
                 

                 
                 

                 http://blog.csdn.net/ithomer/article/details/8737999
                 

                 
                 

                 做項目的時候還發現一個問題，就是WebView的addJavascriptInterface方法失效的問題

                 裡面的類的方法名上面要加annotation
                 @JavascriptInterface
                 

                 表忘了導包import android.webkit.JavascriptInterface;