Question

我使用phonegap android从html字符串创建pdf文件创建了一个示例应用程序。我已经编写了在java.Code中创建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();
    }
    }
}

我的mian类代码是，

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>

我从javascript调用generatePDF我得到了以下错误，

Uncaught TypeError: Cannot call method 'generatePDF' of undefined

请帮帮我。

Answer 1

在DroidGap类中定义一个函数（不）|（不会）|（不应该）将该函数公开给webview javascript环境，也不会通过Window将成员对象公开为DOM对象。

你想要的（如Raymond和Larta所示）是写一个PDF插件。

Here is the documentation for writing a Cordova Plugin

一般来说，你需要 1.原生实施这完全取决于您的插件所针对的平台。在android的情况下，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实施你的看起来可能像 PDFWriter.js： cordova.exec（successCB， failCB， “PDFWriter” “generatePDF” 参数）;

successCB - 是成功回调 failCB - 是失败回调 PDFWriter - 是您调用的本机插件实现 generatePDF - 是您正在调用的本机插件函数 args - 要传递给本机插件函数的参数数组

请注意，这是一个完整的例子，我省略了JAVA中的import语句以及必要的钩子。使用plugman npm模块为您自动生成这些。

无法从phonegap android调用java方法？

1 个答案: