使用Qr掃描儀掃描無效的字符串時，我的應用程序崩潰

Question

我是android的初學者...從qr掃描儀掃描數據...代碼工作正常...假設我掃描了abc之類的字符串...我的應用崩潰了-因為字符較少...如何避免崩潰...如果我在下面的代碼中掃描了一些無效的字符串...有人可以幫助我...

  public void onActivityResult(int requestCode, int resultCode, Intent data) {
    //    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == 0) {
        if (resultCode == Activity.RESULT_OK) {
            String contents = data.getStringExtra("SCAN_RESULT");

            String Id = contents.substring(0, 10),
                    password = contents.substring(10, 14);
            //    formatTxt.setText("FORMAT: " + contents);
            //  contentTxt.setText("CONTENT: " + format);

            Toast toast = Toast.makeText(getActivity(), "" + contents, Toast.LENGTH_LONG);
            toast.show();
          setdetails(id.toString(), password.toString());



      } else if (resultCode == Activity.RESULT_CANCELED) {
      // Handle cancel
       Toast toast = Toast.makeText(getActivity(), " Cancelled", Toast.LENGTH_SHORT);

       toast.show();

  }

    } else
        super.onActivityResult(requestCode, resultCode, data);
}

java.lang.RuntimeException：無法傳送結果ResultInfo {who = android：fragment：0，request = 0，result = -1，data = Intent {act = com.google.zxing.client.android.SCAN flg = 0x80000（has活動{com.application}：java.lang.StringIndexOutOfBoundsException：length = 7; regionStart = 0; regionLength = 10

                                                                           at android.app.ActivityThread.deliverResults(ActivityThread.java:3720)
                                                                          Caused by: java.lang.StringIndexOutOfBoundsException: length=7; regionStart=0; regionLength=10

Answer 1

您需要確保字符串長度不小於14（根據您的情況），並且它也不為null，也可以使用以下代碼：

//...some code ...
String contents = data.getStringExtra("SCAN_RESULT");
if(contents!=null && contents.length() >= 14){
    String Id = contents.substring(0, 10),
    password = contents.substring(10, 14);
    //    formatTxt.setText("FORMAT: " + contents);
    //  contentTxt.setText("CONTENT: " + format);

    Toast toast = Toast.makeText(getActivity(), "" + contents, Toast.LENGTH_LONG);
    toast.show();
    setdetails(id.toString(), password.toString());   
}else{
    Toast toast = Toast.makeText(getActivity(), "Invalid Data", Toast.LENGTH_LONG);
    toast.show();
}

Answer 2

您能告訴您錯誤日志中顯示的錯誤是什么，您使用的是哪種掃描儀。

從zxing開始，條形碼掃描儀本身會顯示錯誤對話框“錯誤，無法解釋QR碼”。 被陳列。