[Android Studio] kuannygohcheetatt:
I'm trying to develop an app to scan for a BLE device. However, it only scans one time. I tried to use a while loop to loop it but it hangs there. The scanning part is at the proceed function:

package com.example.user.myfriend;

import android.bluetooth.BluetoothAdapter;

import android.bluetooth.BluetoothDevice;

import android.bluetooth.BluetoothManager;

import android.content.Context;

import android.content.Intent;

import android.graphics.Color;

import android.os.Handler;

import android.support.v7.app.ActionBarActivity;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.widget.RelativeLayout;

import android.widget.TextView;

import android.widget.Toast;

import org.w3c.dom.Text;

public class MainActivity extends ActionBarActivity {

BluetoothAdapter mBluetoothAdapter;

@Override

protected void onCreate(Bundle savedInstanceState) {

BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);

mBluetoothAdapter = bluetoothManager.getAdapter();

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

hello();

}

public void hello() {

if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {

Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);

startActivityForResult(enableBluetooth, 1);

}

proceed();

}

@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

if (requestCode == 1) {

if (resultCode == RESULT_OK) {

proceed();

}

}

super.onActivityResult(requestCode, resultCode, data);

}

private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {

public void onLeScan(final BluetoothDevice device, final int rssi, final byte[] scanRecord) {

int startByte = 2;

boolean patternFound = false;

while (startByte <= 5) {

if (((int) scanRecord[startByte + 2] & 0xff) == 0x02 && //Identifies an iBeacon

((int) scanRecord[startByte + 3] & 0xff) == 0x15) { //Identifies correct data length

patternFound = true;

break;

}

startByte++;

}

if (patternFound) {

//Convert to hex String

byte[] uuidBytes = new byte[16];

System.arraycopy(scanRecord, startByte + 4, uuidBytes, 0, 16);

String hexString = bytesToHex(uuidBytes);

//Here is your UUID

String uuid = hexString.substring(0, 8) + "-" +

hexString.substring(8, 12) + "-" +

hexString.substring(12, 16) + "-" +

hexString.substring(16, 20) + "-" +

hexString.substring(20, 32);

//Here is your Major value

int major = (scanRecord[startByte + 20] & 0xff) * 0x100 + (scanRecord[startByte + 21] & 0xff);

//Here is your Minor value

int minor = (scanRecord[startByte + 22] & 0xff) * 0x100 + (scanRecord[startByte + 23] & 0xff);

if (major == 1) {

RelativeLayout hai = (RelativeLayout) findViewById(R.id.hai);

hai.setBackgroundColor(Color.YELLOW);

}

if (major == 2) {

RelativeLayout hai = (RelativeLayout) findViewById(R.id.hai);

hai.setBackgroundColor(Color.RED);

}

}

}

};

private static String bytesToHex(byte[] bytes) {

final char[] hexArray = "0123456789ABCDEF".toCharArray();

char[] hexChars = new char[bytes.length * 2];

for (int j = 0; j < bytes.length; j++) {

int v = bytes[j] & 0xFF;

hexChars[j * 2] = hexArray[v >>> 4];

hexChars[j * 2 + 1] = hexArray[v & 0x0F];

}

return new String(hexChars);

}

public void proceed() {

boolean scanning = true;

mBluetoothAdapter.startLeScan(mLeScanCallback);

Handler handler = new Handler();

handler.postDelayed(new Runnable() {

// @Override

public void run() {

mBluetoothAdapter.stopLeScan(mLeScanCallback);

}

}, 50000000);

}