有时候抛出未被捕获的错误：错误调用方法上NPObject在Android [英] Sometimes throws Uncaught Error: Error calling method on NPObject on Android

问题描述

我有关于机器人web视图和JavaScript接口问题。 我打电话传递一个字符串JavascriptInterface的方法。我调试它，我接受正确的字符串在Java中。问题是，有时我得到一个未捕获的错误：错误调用方法上NPObject。有谁知道为什么吗？

---

类：

 公共类JSInterfaceGame扩展JSInterface {

@JavascriptInterface
公共无效setShareText（字符串股）{
    shareText =份额;
    如果（mJSInterfaceListener！= NULL）
        mJSInterfaceListener.onParametersChanged（SHARE_TEXT）;
}
 

GameFragment（onCreateView法）：

 在线=（web视图）rootView.findViewById（R.id.online）;
    WebSettings WS = online.getSettings（）;
    ws.setJavaScriptEnabled（真正的）;
    ws.setUserAgentString（USER_AGENT）;
    ws.setCacheMode（WebSettings.LOAD_DEFAULT）;
    ws.setRenderPriority（WebSettings.RenderPriority.HIGH）;

    online.setWebViewClient（新WISWebviewClient（）{

        @覆盖
        公共无效onStatusChanged（最终的WebView视图，INT进步，持续时间长）{
           //无关
        }
    }）;

    mJSInterface =新JSInterfaceGame（）;
    mJSInterface.setJSInterfaceListener（本）; //我自己的监听器
    。共享preferences设置= getActivity（）getShared preferences（GameActivity preFERENCES，Context.MODE_PRIVATE）;
    mJSInterface.setPlayerName（settings.getString（GameActivity preFS_PlAYERNAME，NULL））;
    online.addJavascriptInterface（mJSInterface，JSInterface）;
    online.loadUrl（HTTP：// ...）;
 

Javascript的部分：

  //文本替换
 功能replaceText（文字）{
    如果（的arguments.length＆其中; = 1）
        返回文本;
    VAR tokenCount的arguments.length =  -  2;
    对于（VAR令牌= 0;令牌LT; = tokenCount;令牌++）
    文= text.replace（新的RegExp（\\ {+令牌+\\}，GI），参数[令牌+ 1]）;
    返回文本;
  }

  功能loadMain（）{
    VAR T = replaceText（语言[sharelink_description]，http://website.org'）;
    的console.log（typeof运算T）; //总是串
    JSInterface.setShareText（T）;
  }

 $（文件）。就绪（函数（）{
      loadMain（）;
  }）;
 

解决方案

在尝试，使用方法，从JavaScript接口调用，与UI交互时发生。要解决它以这种方式：

 类mJSInterface（）
{

公共无效myFunction的（）
{
    runOnUiThread（新的Runnable（）{

            公共无效的run（）{
                // code与UI交互
            }
        }）;

    }

}
 

I am having problems regarding Androids Webview and Javascript Interfaces. I am calling a method passing a String to the JavascriptInterface. I debugged it and I receive the right String in Java. The problem is that sometimes I get an uncaught Error: Error calling method on NPObject. Does anybody know why?

---

Classes:

public class JSInterfaceGame extends JSInterface {

@JavascriptInterface
public void setShareText(String share){
    shareText = share;
    if(mJSInterfaceListener != null)
        mJSInterfaceListener.onParametersChanged(SHARE_TEXT);
}

GameFragment (onCreateView-Method):

    online = (WebView) rootView.findViewById(R.id.online);
    WebSettings ws = online.getSettings();
    ws.setJavaScriptEnabled(true);
    ws.setUserAgentString(USER_AGENT);
    ws.setCacheMode(WebSettings.LOAD_DEFAULT);
    ws.setRenderPriority(WebSettings.RenderPriority.HIGH);

    online.setWebViewClient(new WISWebviewClient() {

        @Override
        public void onStatusChanged(final WebView view, int progress, long duration) {
           //unrelated
        }
    });

    mJSInterface = new JSInterfaceGame();
    mJSInterface.setJSInterfaceListener(this); //my own listener
    SharedPreferences settings = getActivity().getSharedPreferences(GameActivity.PREFERENCES, Context.MODE_PRIVATE);
    mJSInterface.setPlayerName(settings.getString(GameActivity.PREFS_PlAYERNAME, null));
    online.addJavascriptInterface(mJSInterface, JSInterface");
    online.loadUrl("http://....");

Javascript Part:

 //Text Replacements
 function replaceText( text ) {
    if ( arguments.length <= 1 )
        return text;
    var tokenCount = arguments.length - 2;
    for( var token = 0; token <= tokenCount; token++ )
    text = text.replace( new RegExp( "\\{" + token + "\\}", "gi" ), arguments[ token + 1 ] );
    return text;
  }

  function loadMain() {
    var t = replaceText(language["sharelink_description"], 'http://website.org');
    console.log(typeof t); //always string
    JSInterface.setShareText(t);
  }

 $(document).ready(function(){
      loadMain();
  });

解决方案

It happens when you try, using method called from javascript interface, to interact with UI. To solved it in this way:

class mJSInterface()
{

public void myFunction()
{
    runOnUiThread(new Runnable() {

            public void run() {
                //Code that interact with UI
            }
        });

    }

}

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