I am developing an application where I have to connect to Bluetooth device on Android 4.3.
我正在开发一个应用程序，我必须连接到Android 4.3上的蓝牙设备。
I can scan the bluetooth device, but it can not connect the bluetooth device.
我可以扫描蓝牙设备，但它无法连接蓝牙设备。
I have already add the permission in Manifest of the following:
我已经在Manifest中添加了以下权限：
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH" />
My Operation is when I push SCAN Button, it will scan the Bluetooth device and show on the ListView.
我的操作是当我按下SCAN按钮时，它将扫描蓝牙设备并在ListView上显示。
When I click the bluetooth device on ListView,it will connect the bluetooth device of item.
当我点击ListView上的蓝牙设备时，它将连接项目的蓝牙设备。
But when I click the device item, the app will crash, and I don't know why...
但是当我点击设备项目时，应用程序会崩溃，我不知道为什么......
This is my java code:
这是我的java代码：
package com.example.preventthelost;
import java.io.IOException;
import java.net.Socket;
import java.util.Set;
import java.util.UUID;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Toast;
public class DeviceList extends Activity {
protected static final String tag = "TAG";
private BluetoothAdapter mBluetoothAdapter;
private static final int REQUEST_ENABLE_BT=1;
private Button btn_cancel;
private Button btn_scan;
private ListView pair_devices_list;
private ListView new_devices_list;
private Set<BluetoothDevice> pairedDevice;
private ArrayAdapter<String> newDevicelistArrayAdapter;
private ArrayAdapter<String> pairDevicelistArrayAdapter;
private final UUID my_UUID = UUID.fromString("00001802-0000-1000-8000-00805f9b34fb");
//private final UUID my_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
private BluetoothSocket socket;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.device_list);
btn_scan = (Button)findViewById(R.id.btn_scan);
newDevicelistArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
new_devices_list = (ListView)findViewById(R.id.new_devices_list);
new_devices_list.setAdapter(newDevicelistArrayAdapter);
**//check device support bluetooth or not**
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if(mBluetoothAdapter == null) {
Toast.makeText(this, "No support bluetooth", Toast.LENGTH_SHORT).show();
finish();
return;
}else if(!mBluetoothAdapter.isEnabled()){ **//if bluetooth is close, than open it**
Intent enableBTIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBTIntent, REQUEST_ENABLE_BT);
}
**//click the scan button**
btn_scan.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
//**list the bluetooth device**
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter);
mBluetoothAdapter.startDiscovery();
newDevicelistArrayAdapter.clear();
}
});
//new_devices_list click
new_devices_list.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
mBluetoothAdapter.cancelDiscovery();
final String info = ((TextView) arg1).getText().toString();
//get the device address when click the device item
String address = info.substring(info.length()-19);
//connect the device when item is click
BluetoothDevice connect_device = mBluetoothAdapter.getRemoteDevice(address);
try {
socket = connect_device.createRfcommSocketToServiceRecord(my_UUID);
socket.connect();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});//************new_devices_list end
}
public final BroadcastReceiver mReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
String action = intent.getAction();
if(BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice bdevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
//short rssi = intent.getExtras().getShort(BluetoothDevice.EXTRA_RSSI);;
if(bdevice.getBondState() != BluetoothDevice.BOND_BONDED)
newDevicelistArrayAdapter.add("\n" + bdevice.getName() + "\n" + bdevice.getAddress());
newDevicelistArrayAdapter.notifyDataSetChanged();
}
}
};
protected void onDestroy() {
super.onDestroy();
if(mBluetoothAdapter != null)
mBluetoothAdapter.cancelDiscovery();
unregisterReceiver(mReceiver);
}
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.device_list, menu);
return true;
}
}
when I type the connect code of following into new_devices_list.setOnItemClickListener, it always crash.
当我在new_devices_list.setOnItemClickListener中键入以下连接代码时，它总是崩溃。
//get the device address when click the device item
String address = info.substring(info.length()-19);
//connect the device when item is click
BluetoothDevice connect_device = mBluetoothAdapter.getRemoteDevice(address);
try {
socket = connect_device.createRfcommSocketToServiceRecord(my_UUID);
socket.connect();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
I am not sure, but the problem look like in this line:
我不确定，但问题看起来像这一行：
BluetoothDevice connect_device = mBluetoothAdapter.getRemoteDevice(address);
BluetoothDevice connect_device = mBluetoothAdapter.getRemoteDevice（address）;
The data type of the address is String rather address.
地址的数据类型是String而不是地址。
But the type of getRemoteDevice I choose is String address.
但我选择的getRemoteDevice类型是String地址。
SO...I don't know Why the app always crash when I type the connect code in new_devices_list even??
所以...我不知道为什么当我在new_devices_list中键入连接代码时应用程序总是崩溃？
Does it can not be use in Android 4.3 ??
它是不是可以在Android 4.3中使用？
Can someone teach me??
有人可以教我吗？
Thanks!!
谢谢！！
3 个解决方案
#1
3
It was not clear if you are connecting Bluetooth Classic or a Low Energy device. Your code is for Classic, the tag suggests Low Energy. In case the Low Energy you would use
您是否正在连接Bluetooth Classic或Low Energy设备尚不清楚。你的代码是经典的，标签暗示低能量。如果您将使用低能量
device.connectGatt(this, false, mGattCallback);
instead of
代替
connect_device.createRfcommSocketToServiceRecord(my_UUID);
#2
1
You select Tag BluetoothLowEnergy. Your question is about BLE or standard Bluetooth? for BLE there is another approach to connect. You can read here
您选择Tag BluetoothLowEnergy。您的问题是关于BLE还是标准蓝牙？对于BLE，还有另一种连接方法。你可以在这里阅读
#3
1
I had a similar problem, but just found a solution.
我有类似的问题，但刚刚找到了解决方案。
Instead of subtracting 19 from info.length() in
而不是从info.length（）中减去19
String address = info.substring(info.length()-19);
subtract 17 instead. The original post is posted almost a year ago, but hopefully it's still helpful to those who have the same problem.
相反减去17。原帖几乎在一年前发布，但希望它仍然对那些有同样问题的人有帮助。
#1
3
It was not clear if you are connecting Bluetooth Classic or a Low Energy device. Your code is for Classic, the tag suggests Low Energy. In case the Low Energy you would use
您是否正在连接Bluetooth Classic或Low Energy设备尚不清楚。你的代码是经典的，标签暗示低能量。如果您将使用低能量
device.connectGatt(this, false, mGattCallback);
instead of
代替
connect_device.createRfcommSocketToServiceRecord(my_UUID);
#2
1
You select Tag BluetoothLowEnergy. Your question is about BLE or standard Bluetooth? for BLE there is another approach to connect. You can read here
您选择Tag BluetoothLowEnergy。您的问题是关于BLE还是标准蓝牙？对于BLE，还有另一种连接方法。你可以在这里阅读
#3
1
I had a similar problem, but just found a solution.
我有类似的问题，但刚刚找到了解决方案。
Instead of subtracting 19 from info.length() in
而不是从info.length（）中减去19
String address = info.substring(info.length()-19);
subtract 17 instead. The original post is posted almost a year ago, but hopefully it's still helpful to those who have the same problem.
相反减去17。原帖几乎在一年前发布，但希望它仍然对那些有同样问题的人有帮助。