如何在Android中扫描QRCode

try {    Intent intent = new Intent("com.google.zxing.client.android.SCAN");    intent.putExtra("SCAN_MODE", "QR_CODE_MODE"); // "PRODUCT_MODE for bar pres    startActivityForResult(intent, 0);} catch (Exception e) {        Uri marketUri = Uri.parse("market://details?id=com.google.zxing.client.android");    Intent marketIntent = new Intent(Intent.ACTION_VIEW,marketUri);    startActivity(marketIntent);}

和在

onActivityResult():

@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {    super.onActivityResult(requestCode, resultCode, data);    if (requestCode == 0) {        if (resultCode == RESULT_OK) { String contents = data.getStringExtra("SCAN_RESULT");        }        if(resultCode == RESULT_CANCELLED){ //handle cancel        }    }}