安卓zxing intentintegrator [英] android zxing intentintegrator

问题描述

我已经写了下面的code，如果你决定要扫描QR code（使用zxing）并将其存储在专用存储，但如果你决定要取消扫描工作正常，崩溃和文件previously存储的内容就会消失。

我想这可能是一个设计错误，不知道为什么。

下面是有关code

  .../ **
 *菜单生成
 * /
@覆盖
公共布尔onCreateOptionsMenu（菜单菜单）{
    MenuInflater吹气= getMenuInflater（）;
    inflater.inflate（R.menu.menu，菜单）;
    返回true;
}/ **
 *菜单处理
 * /
@覆盖
公共布尔onOptionsItemSelected（菜单项项）{
    上下文的背景下= getApplicationContext（）;
    烤面包烤面包= Toast.makeText（上下文，，Toast.LENGTH_LONG）;
    toast.setGravity（Gravity.FILL_HORIZONTAL，0，0）;
    开关（item.getItemId（））{
        案例R.id.qrScan：
            IntentIntegrator积分=新IntentIntegrator（本）;
            integrator.initiateScan（）;
            返回true;
        案例R.id.qrReset：
            文件DIR = getFilesDir（）;
            档案文件=新的文件（目录，QR codeFILE）;
            布尔删除= file.delete（）;
            返回true;
        案例R.id.appClose：
            this.finish（）;
            返回true;
        默认：
            返回super.onOptionsItemSelected（项目）;
    }
}...    公共无效的onActivityResult（INT申请code，INT结果code，意图意图）{
    IntentResult scanResult = IntentIntegrator.parseActivityResult（要求code，结果code，意向）;
    上下文的背景下= getApplicationContext（）;
    烤面包烤面包= Toast.makeText（上下文，，Toast.LENGTH_SHORT）;
    如果（scanResult！= NULL）{
        FOS的FileOutputStream = NULL;
        CharSequence的文字= scanResult.getContents（）;
        尝试{
            FOS = openFileOutput（QR codeFILE，Context.MODE_PRIVATE）;
            尝试{
                fos.write（text.toString（）的getBytes（））;
                fos.close（）;
                toast.setGravity（Gravity.FILL_HORIZONTAL，0，0）;
                toast.setText（code保存）;
                toast.show（）;
            }赶上（IOException异常前）{
                toast.setGravity（Gravity.FILL_HORIZONTAL，0，0）;
                toast.setText（无效code）;
                toast.show（）;
                。Logger.getLogger（MainActivity.class.getName（））日志（Level.SEVERE，空，前）;
            }
        }赶上（FileNotFoundException异常前）{
                toast.setGravity（Gravity.FILL_HORIZONTAL，0，0）;
                toast.setText（错误，同时节省）;
                toast.show（）;
            。Logger.getLogger（MainActivity.class.getName（））日志（Level.SEVERE，空，前）;
        }
    }其他{
        toast.setGravity（Gravity.FILL_HORIZONTAL，0，0）;
        toast.setText（无效code）;
        toast.show（）;
    }
}
 

解决方案

您需要检查结果code 。如果扫描被取消，没有了吧code值的信息。随着结果code 您可以检查是否操作成功与否。

 如果（结果code == RESULT_OK）{
    //扫描成功
}其他{
    // 没有结果
}
 

I've written the following code that works fine if you decide to scan a QR code (using zxing) and store it in private storage but in case you decide to cancel scanning, it crashes and the file previously stored content disappears.

I think it might be a design error, not sure why.

Below is relevant code

...

/**
 * menu generation
 */
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu, menu);
    return true;
}

/**
 * menu handling
 */
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    Context context = getApplicationContext();
    Toast toast = Toast.makeText(context, "", Toast.LENGTH_LONG);
    toast.setGravity(Gravity.FILL_HORIZONTAL, 0, 0);
    switch (item.getItemId()) {
        case R.id.qrScan:
            IntentIntegrator integrator = new IntentIntegrator(this);
            integrator.initiateScan();
            return true;
        case R.id.qrReset:
            File dir = getFilesDir();
            File file = new File(dir, qrCodeFile);
            boolean deleted = file.delete();
            return true;
        case R.id.appClose:
            this.finish();
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
} 

...

    public void onActivityResult(int requestCode, int resultCode, Intent intent) {
    IntentResult scanResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, intent);
    Context context = getApplicationContext();
    Toast toast = Toast.makeText(context, "", Toast.LENGTH_SHORT);
    if (scanResult != null) {
        FileOutputStream fos = null;
        CharSequence text = scanResult.getContents();
        try {
            fos = openFileOutput(qrCodeFile, Context.MODE_PRIVATE);
            try {
                fos.write(text.toString().getBytes());
                fos.close();
                toast.setGravity(Gravity.FILL_HORIZONTAL, 0, 0);
                toast.setText("Code saved");
                toast.show();
            } catch (IOException ex) {
                toast.setGravity(Gravity.FILL_HORIZONTAL, 0, 0);
                toast.setText("Invalid code");
                toast.show();
                Logger.getLogger(MainActivity.class.getName()).log(Level.SEVERE, null, ex);
            }
        } catch (FileNotFoundException ex) {
                toast.setGravity(Gravity.FILL_HORIZONTAL, 0, 0);
                toast.setText("Error while saving");
                toast.show();
            Logger.getLogger(MainActivity.class.getName()).log(Level.SEVERE, null, ex);
        }
    }   else {
        toast.setGravity(Gravity.FILL_HORIZONTAL, 0, 0);
        toast.setText("Invalid code");
        toast.show();           
    }  
}

解决方案

You need to check the resultCode. If the scan is canceled there is no information about the barcode value. With the resultCode you can check if the operation was successful or not.

if(resultCode == RESULT_OK) {
    // scan successful
} else {
    // no result
}

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