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[英]Reading RSSI value of connected Bluetooth Low Energy device in Android Studio
[英]Bluetooth Low Energy Rssi Android
我正在开发一个必须连接到Android 4.3上的Bluetooth Low Energy设备的应用程序。 我试图这样做以在我的应用程序中显示rssi,但是它不起作用
@Override
public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) {
//final LeDeviceListAdapter deviceLe = new LeDeviceListAdapter(device, rssi, scanRecord);
runOnUiThread(new Runnable() {
@Override
public void run() {
mLeDeviceListAdapter.addDevice(device,rssi);
mLeDeviceListAdapter.notifyDataSetChanged();
}
});
我的列表适配器代码是:
private class LeDeviceListAdapter extends BaseAdapter {
private ArrayList<BluetoothDevice> mLeDevices;
private LayoutInflater mInflator;
public LeDeviceListAdapter() {
super();
mLeDevices = new ArrayList<>();
mInflator = MainActivity.this.getLayoutInflater();
}
public void addDevice(BluetoothDevice device) {
if (!mLeDevices.contains(device)) {
mLeDevices.add(device);
}
}
public BluetoothDevice getDevice(int position) {
return mLeDevices.get(position);
}
public void clear() {
mLeDevices.clear();
// notifyDataSetChanged();
}
@Override
public int getCount() {
return mLeDevices.size();
}
@Override
public Object getItem(int i) {
return mLeDevices.get(i);
}
@Override
public long getItemId(int i) {
return i;
}
@Override
public View getView(int i, View view, ViewGroup viewGroup) {
ViewHolder viewHolder;
// General ListView optimization code.
if (view == null) {
view = mInflator.inflate(R.layout.listitem_device,viewGroup, false);
viewHolder = new ViewHolder();
viewHolder.deviceAddress = (TextView) view.findViewById(R.id.device_address);
viewHolder.deviceName = (TextView) view.findViewById(R.id.device_name);
// viewHolder.signal = (TextView) view.findViewById(R.id.device_signal);
view.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) view.getTag();
}
BluetoothDevice device = mLeDevices.get(i);
//final String rssi_s=device.getRssi();
final String deviceName = device.getName();
/* ScanResult rssi=null;
final double rssi_s = rssi.getRssi();
String rssiString = String.valueOf(rssi_s);*/
//final String rssiString =getString(valueOf(rssi_s));
if
(deviceName != null && deviceName.length() > 0){
viewHolder.deviceName.setText(deviceName);
// viewHolder.signal.setText(rssiString);
}
else
viewHolder.deviceName.setText(R.string.unknown_device);
viewHolder.deviceAddress.setText(device.getAddress());
return view;
}
}
// Device scan callback.
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) {
//final LeDeviceListAdapter deviceLe = new LeDeviceListAdapter(device, rssi, scanRecord);
runOnUiThread(new Runnable() {
@Override
public void run() {
// String rssi_signal=String.valueOf(rssi);
mLeDeviceListAdapter.addDevice(device);
mLeDeviceListAdapter.notifyDataSetChanged();
}
});
}
};
static class ViewHolder {
TextView deviceName;
TextView deviceAddress;
//TextView signal;
}
你有什么主意我可以显示吗? 我仍然需要在oncreate方法中键入此内容吗?
mLeDeviceListAdapter=new LeDeviceListAdapter();
您的问题是(1)适配器本身没有用于跟踪RSSI值的方法,并且(2)您适配器的列表项视图无法显示RSSI值,并且适配器本身没有用于跟踪RSSI值的方法RSSI值。 这里是详细的问题:
问题1列表适配器不能跟踪RSSI值。
您通过以下调用将设备和RSSI值添加到适配器:
mLeDeviceListAdapter.addDevice(device,rssi);
但是适配器只有这样的方法:
public void addDevice(BluetoothDevice device) {
if (!mLeDevices.contains(device)) {
mLeDevices.add(device);
}
}
如您所见,方法不匹配。 我建议执行以下操作:首先创建一个新类,该类将同时包含BluetoothDevice和RSSI值。 像这样:
private class LeScanRecord {
public final BluetoothDevice device;
public final int rssi;
public LeScanRecord(BluetoothDevice device, int rssi) {
this.device = device;
this.rssi = rssi;
}
}
然后将您的适配器更改为接受新类的跟踪实例(请注意,此问题通过使用RSSI值填充文本字段来解决问题2 ):
/**
* Adapter for the scan record devices
*/
private class LeDeviceListAdapter extends ArrayAdapter<LeScanRecord >
{
/**
* View inflater
*/
private final LayoutInflater inflater;
public LeDeviceListAdapter ()
{
super(MainActivity.this, R.layout.listitem_device);
inflater = MainActivity.this.getLayoutInflater();
}
@Override
public void add(LeScanRecord object)
{
for (int i = 0; i < getCount(); i++)
{
if (getItem(i).device.equals(object.device))
{
return; // do not add duplicates
}
}
super.add(object);
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
ViewHolder viewHolder;
// General ListView optimization code.
if (view == null) {
view = mInflator.inflate(R.layout.listitem_device,viewGroup, false);
viewHolder = new ViewHolder();
viewHolder.deviceAddress = (TextView) view.findViewById(R.id.device_address);
viewHolder.deviceName = (TextView) view.findViewById(R.id.device_name);
viewHolder.rssi= (TextView) view.findViewById(R.id.device_signal);
view.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) view.getTag();
}
LeScanRecord record = getItem(position);
final String deviceName = record.device.getName();
if (deviceName != null && deviceName.length() > 0){
viewHolder.deviceName.setText(deviceName);
}
else {
viewHolder.deviceName.setText(R.string.unknown_device);
}
viewHolder.deviceAddress.setText(record.device.getAddress());
viewHolder.rssi.setText(Integer.valueOf(record.rssi));
return view;
}
}
static class ViewHolder {
public TextView deviceName;
public TextView deviceAddress;
public TextView rssi;
}
最后要做的是将扫描记录的实例添加到适配器。 所以改变:
@Override
public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) {
//final LeDeviceListAdapter deviceLe = new LeDeviceListAdapter(device, rssi, scanRecord);
runOnUiThread(new Runnable() {
@Override
public void run() {
mLeDeviceListAdapter.addDevice(device,rssi);
mLeDeviceListAdapter.notifyDataSetChanged();
}
});
}
至:
@Override
public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) {
runOnUiThread(new Runnable() {
@Override
public void run() {
mLeDeviceListAdapter.add(new LeScanRecord(device, rssi));
mLeDeviceListAdapter.notifyDataSetChanged();
}
});
}
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