Question

这是我的代码

package com.javacodegeeks.androidqrcodeexample;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.ActivityNotFoundException;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;

public class AndroidBarcodeQrExample extends Activity {
    /** Called when the activity is first created. */

    static final String ACTION_SCAN = "com.google.zxing.client.android.SCAN";
    String disco = null;
    String QRCode_result = null;
    WebView webView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        webView = (WebView) findViewById(R.id.webView);
        setContentView(R.layout.activity_main);


        //PRENDO IL NOME UTENTE DALLA PRECEDENTE SCHEDA
        Bundle extras = getIntent().getExtras();
        if (extras != null) {
            disco = extras.getString("Disco");
        }




        }

    public void scanQR(View v) {
        try {
            Intent intent = new Intent(ACTION_SCAN);
            intent.putExtra("SCAN_MODE", "QR_CODE_MODE");
            startActivityForResult(intent, 0);
        } catch (ActivityNotFoundException anfe) {
            showDialog(AndroidBarcodeQrExample.this, "Nessuno Scanner Trovato", "Scarica subito uno Scanner", "Si", "No").show();
        }
    }

    private static AlertDialog showDialog(final Activity act, CharSequence title, CharSequence message, CharSequence buttonYes, CharSequence buttonNo) {
        AlertDialog.Builder downloadDialog = new AlertDialog.Builder(act);
        downloadDialog.setTitle(title);
        downloadDialog.setMessage(message);
        downloadDialog.setPositiveButton(buttonYes, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialogInterface, int i) {
                Uri uri = Uri.parse("market://search?q=pname:" + "com.google.zxing.client.android");
                Intent intent = new Intent(Intent.ACTION_VIEW, uri);
                try {
                    act.startActivity(intent);
                } catch (ActivityNotFoundException anfe) {

                }
            }
        });
        downloadDialog.setNegativeButton(buttonNo, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialogInterface, int i) {
            }
        });
        return downloadDialog.show();
    }

    public void onActivityResult(int requestCode, int resultCode, Intent intent) {
        if (requestCode == 0) {
            if (resultCode == RESULT_OK) {
                String contents = intent.getStringExtra("SCAN_RESULT");
                String format = intent.getStringExtra("SCAN_RESULT_FORMAT");
                QRCode_result = contents;

                //Prendo il primo numero
                char Check = QRCode_result.charAt(0);

                    if (Check == '0') {
                        String url = "http://www.bparty.org/APP/localsite/CONNECT_ANDROID_QR.php?disco=" + disco + "&string=" + QRCode_result;
                        url = url.replace(" ", "%20");
                        Log.i("URL",url);
                        webView.loadUrl(url);
                        //ALLORA E' UN CODICE UNIVOCO LISTA
                        QRCode_result = "QRCode PER LISTA";
                    }
                    else if (Check == '1') {
                        // ALLORA E' UN CODICE DI TICKET COMPRATO
                        QRCode_result = "QRCode PER TICKET";
                    }
                    else {
                        //ALLORA NON ESISTE
                        QRCode_result = "QRCode NON VALIDO";
                    }



                Toast toast = Toast.makeText(this, "Content:" + QRCode_result, Toast.LENGTH_LONG);
                toast.show();
            }
        }
    }
}

当我在qrcode扫描后运行应用程序时出现此错误：

06-15 03：43：27.809 11140-11140 / com.javacodegeeks.androidqrcodeexample E / AndroidRuntime：致命异常：主要 java.lang.RuntimeException：传递结果失败ResultInfo {who = null，request = 0，result = -1，data = Intent { act = com.google.zxing.client.android.SCAN flg = 0x80000（有额外内容）}} 活动 {com.javacodegeeks.androidqrcodeexample / com.javacodegeeks.androidqrcodeexample.AndroidBarcodeQrExample}：显示java.lang.NullPointerException

我认为这是因为网页视图未初始化良好.. 不是吗？

Answer 1

在onCreate()方法中，在webView

之后移动setContentView初始化

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        webView = (WebView) findViewById(R.id.webView);
        .....
   }

Web视图错误加载活动

1 个答案: