android QR code scanning

Go directly to the demo address, I don't know what to write https://github.com/wudongze/QrScan-master

When calling this code

 

QrScan.getInstance().launchScan(MainActivity.this, new IScanModuleCallBack() {
    @Override
public void OnReceiveDecodeResult(final Context context, String result) {
        mCaptureContext = (CaptureActivity)context;

AlertDialog dialog = new AlertDialog.Builder(mCaptureContext)
                .setMessage(result)
                .setCancellable( false )
                .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                    @Override
public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
QrScan.getInstance().restartScan(mCaptureContext);
}
                })
                .setPositiveButton("关闭", new DialogInterface.OnClickListener() {
                    @Override
public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
QrScan.getInstance().finishScan(mCaptureContext);
}
                })
                .create();
dialog.show();
}
});