无法从Phonegap Android调用Java方法？

Question

I have created one sample app from create pdf file from html string using phonegap android.I have write the code for Creating PDF file in java.Code, 我已经使用phonegap android从html字符串创建pdf文件创建了一个示例应用程序。我在java.Code中编写了用于创建PDF文件的代码，

public class PdfGenerator
{
    private WebView mAppView;
    private DroidGap mGap;
    public PdfGenerator(DroidGap gap, WebView view)
    {
        mAppView = view;
        mGap = gap;
    }

    public void generatePDF()
    {
         File root = Environment.getExternalStorageDirectory();

         File gpxfile = new File(root, "test.pdf");
         System.out.println("Path ::::"+gpxfile);
         try{
         Document document = new Document(PageSize.LETTER);
          PdfWriter.getInstance(document, new FileOutputStream(gpxfile));
          document.open();
          document.addAuthor("Real Gagnon");
          document.addCreator("Real's HowTo");
          document.addSubject("Thanks for your support");
          document.addCreationDate();
          document.addTitle("Please read this");

          HTMLWorker htmlWorker = new HTMLWorker(document);
          String str = "<html><head></head><body>"+
            "<a href='http://www.rgagnon.com/howto.html'><b>Real's HowTo</b></a>" +
            "<h1>Show your support</h1>" +
            "<p>It DOES cost a lot to produce this site - in ISP storage and transfer fees, " +
            "in personal hardware and software costs to set up test environments, and above all," +
            "the huge amounts of time it takes for one person to design and write the actual content." +
            "<p>If you feel that effort has been useful to you, perhaps you will consider giving something back?" +
            "<p>Donate using PayPal® to real@rgagnon.com." +
            "<p>Contributions via PayPal are accepted in any amount " +
            "<P><br><table border='1'><tr><td>Java HowTo<tr>" +
            "<td bgcolor='red'>Javascript HowTo<tr><td>Powerbuilder HowTo</table>" +
            "</body></html>";
          htmlWorker.parse(new StringReader(str));
          document.close();
          System.out.println("Done");
          }
        catch (Exception e) {
          e.printStackTrace();
    }
    }
}

my mian class code is, 我的班级代码是

public class MainActivity extends DroidGap
{
    PdfGenerator pdf;
    public void onCreate(Bundle savedInstanceState)
    {

        super.onCreate(savedInstanceState);      
        super.init();   

        pdf = new PdfGenerator(this, appView);    
        appView.addJavascriptInterface(pdf, "PdfGenerator");

        super.loadUrl("file:///android_asset/www/test.html");
    }
}

Javascript code, Javascript代码

<html>
  <head>
    <meta name="viewport" content="width=320; user-scalable=no" />
    <meta http-equiv="Content-type" content="text/html; charset=utf-8">

    <script type="text/javascript" charset="utf-8" src="cordova.js"></script>

    <script>
   function pdf()
   {
   document.addEventListener("deviceReady", deviceReady, false);
   }

   function creatfile()
   {
    window.PdfGenerator.generatePDF();
   }



function deviceReady() {
    window.PdfGenerator.generatePDF();
}

    </script>

  </head>

  <body>
  <input type="submit" onclick="pdf()" value="IMEI" />
  </body>

whan i call generatePDF from javascript i got the following error, 当我从javascript调用generatePDF时，出现以下错误，

Uncaught TypeError: Cannot call method 'generatePDF' of undefined

Please help me. 请帮我。

Answer 1

Defining a function inside the DroidGap class (does not)|(will not)|(should not) expose that function to the webview javascript environment, nor will it expose member objects as DOM objects through Window. 在DroidGap类内定义一个函数（不会）|（不会）|（不应）将该函数暴露给webview javascript环境，也不会通过Window将成员对象暴露为DOM对象。

What you want (as indicated by Raymond and Larta) is to write a PDF plugin. 您想要的（如Raymond和Larta所示）是编写一个PDF插件。

Here is the documentation for writing a Cordova Plugin 这是编写Cordova插件的文档

In general, you need 1. Native Implementation this depends entirely on the platform your plugin is written for. 通常，您需要1.本机实现，这完全取决于您的插件所针对的平台。 In the case of android, you can find the native plugin 如果是android，您可以找到本机插件

public class PDFWriter extends CordovaPlugin {

    @Override
    public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException {
        if (action.equals("generatePDF")) {
            // CALL YOUR GENERATE PDF CODE HERE
            return true;
        }
        return false;
    }
}

JS Implementation yours might look something like PDFWriter.js: cordova.exec(successCB, failCB, "PDFWriter", "generatePDF", args); 您的JS实现看起来可能类似于PDFWriter.js：cordova.exec（successCB，failCB，“ PDFWriter”，“ generatePDF”，args）;

successCB - is the success callback failCB - is the fail callback PDFWriter - is the native plugin implementation you are calling generatePDF - is the native plugin function you are calling args - an array of arguments to be passed to the native plugin function successCB-是成功回调函数failCB-是失败回调函数 PDFWriter-是您正在调用的本机插件实现generatePDF-是您正在调用args的本机插件函数-要传递给本机插件函数的参数数组

Note that this is note a complete example, I've omitted the import statements in JAVA as well as the necessary hooks. 请注意，这是一个完整的示例，我省略了JAVA中的import语句以及必要的钩子。 Use the plugman npm module to autogenerate these for you. 使用plugman npm模块为您自动生成这些。

无法从Phonegap Android调用Java方法？

问题描述

1 个解决方案

解决方案1
0 2014-07-25 17:42:30

无法从Phonegap Android调用Java方法？

问题描述

1 个解决方案

解决方案1 0 2014-07-25 17:42:30

解决方案1
0 2014-07-25 17:42:30