Android之如何使用javascript調用android代碼

最後更新：2018-12-06 來源：互聯網

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使用javascript調用android代碼

1.使用webview對象的addJavascriptInterface方法

2.addJavascriptInterface方法有兩個參數，第一個參數就是我們一般會實現一個自己的類，類裡面提供我們要提供給javascript訪問的方法；第二個參數是訪問我們在obj中聲明的方法時候所用到的js對象，調用模式為window.interfaceName.方法名()或者是javascript:
interfaceName.方法名() ;，如myWebView.addJavascriptInterface(new JavaScriptinterface(this),
"android");

3.編寫JavaScriptinterface類，如有一個函數名為showToast()的方法

4.在html中調用時的形式：javascript：android.showToast()。
附上一個小例子:

import android.content.Context;
import android.widget.Toast;

public class JavaScriptinterface {

private Context mContext;

    /** Instantiate the interface and set the context */
    public JavaScriptinterface(Context c) {
        mContext = c;
    }

    /** Show a toast from the web page */
    public void showToast(String toast) {
        Toast.makeText(mContext, toast, Toast.LENGTH_SHORT).show();
    }
}

import java.io.BufferedReader;
import java.io.File;
import java.io.InputStreamReader;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.KeyEvent;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends Activity {
/** Called when the activity is first created. */
private WebView myWebView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        myWebView = (WebView) findViewById(R.id.myWebView);
        myWebView.getSettings().setJavaScriptEnabled(true);
        myWebView.addJavascriptInterface(new JavaScriptinterface(this),
                "android");
        String htmlText = getFromAssets("test.html");
        //把myWebView載入html
        myWebView.loadData(htmlText, "text/html", "utf-8");
        myWebView.setWebViewClient(new myWebViewClient());

    }

    // 此按鍵監聽的是返回鍵，能夠返回到上一個網頁（通過網頁的hostlistery）
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) {
            myWebView.goBack();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

    public String getFromAssets(String fileName) {
        try {
            InputStreamReader inputReader = new InputStreamReader(
                    getResources().getAssets().open(fileName));

BufferedReader bufReader = new BufferedReader(inputReader);

String line = "";
String Result = "";

            while ((line = bufReader.readLine()) != null)
                Result += line;
            if (bufReader != null)
                bufReader.close();
            if (inputReader != null)
                inputReader.close();
            return Result;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

class myWebViewClient extends WebViewClient {

        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            // TODO Auto-generated method stub
            view.loadUrl(url);
            return true;
        }

}
}

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh-CN" dir="ltr">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />

</head>
<body>
<input type="button" value="Say hello"
onClick="showAndroidToast('Hello Android!')" />
</body>
</html>

android的應用程式中,可以直接調用WebView 中的javascript 代碼：import java.io.BufferedReader;
import java.io.File;
import java.io.InputStreamReader;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;

public class MainActivity02 extends Activity {
    /** Called when the activity is first created. */
    private WebView webView;
      private Button button;
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.main2);

          webView=(WebView) this.findViewById(R.id.webView);
          button=(Button) this.findViewById(R.id.button);

          WebSettings setting=webView.getSettings();
          //設定支援javascript
          setting.setJavaScriptEnabled(true);
            //增加介面方法,讓html頁面調用
          webView.addJavascriptInterface(new Object(){
              //這裡我定義了一個撥打的方法
              public void startPhone(String num){
                  Intent intent=new Intent();

                  intent.setAction(Intent.ACTION_CALL);
                  intent.setData(Uri.parse("tel:"+num));
                  startActivity(intent);
              }
          }, "demo");
          //載入頁面
          webView.loadUrl("file:///android_asset/test2.html");

          button.setOnClickListener(new OnClickListener() {

              @Override
              public void onClick(View v) {
                  // TODO Auto-generated method stub
                  webView.loadUrl("javascript:show('activity傳過來的資料')"); //調用javascript函數
                  /*
                  * 通過webView.loadUrl("javascript:xxx")方式就可以調用當前網頁中的名稱
                  * 為xxx的javascript方法
                  */
              }
          });
}

}

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
     function show(content){
         document.getElementById("countent").innerHTML=
             "這是我的javascript調用. 這是："+content;
     }
</script>
</head>
<body>
  <table align="center">
     <tr><td>姓名</td><td>電話</td></tr>
     <tr><td>小明</td><td><a  href="javascript:demo.startPhone(123)">123</a></td></tr>
     <tr><td>小王</td><td><a  href="javascript:demo.startPhone(456)">456</a></td></tr>
  </table>
  <p id="countent">html未經處理資料</p>
</body>
</html>

本文章原先以中文撰寫並發佈於 aliyun.com，亦設英文版本，僅作資訊用途。本網站不對文章的準確性，完整性或可靠性或其任何翻譯作出任何明示或暗示的陳述或保證。如對該文章有任何疑慮或投訴，請傳送電郵至 info-contact@alibabacloud.com 並提供相關疑慮或投訴的詳細說明。職員會於 5 個工作天內與您聯絡，一經驗證之後，即會刪除該侵權內容。

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