当没有匹配的设备和没有找到可用设备的时候。
// If there are paired devices, add each one to the ArrayAdapter if (pairedDevices.size() > 0) { findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE); for (BluetoothDevice device : pairedDevices) { mPairedDevicesArrayAdapter.add(device.getName() + " " + device.getAddress()); } } else { String noDevices = getResources().getText(R.string.none_paired).toString(); mPairedDevicesArrayAdapter.add(noDevices); }
// When discovery finds a device if (BluetoothDevice.ACTION_FOUND.equals(action)) { // Get the BluetoothDevice object from the Intent BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); // If it's already paired, skip it, because it's been listed already if (device.getBondState() != BluetoothDevice.BOND_BONDED) { mNewDevicesArrayAdapter.add(device.getName() + " " + device.getAddress()); } // When discovery is finished, change the Activity title } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) { setProgressBarIndeterminateVisibility(false); setTitle(R.string.select_device); if (mNewDevicesArrayAdapter.getCount() == 0) { String noDevices = getResources().getText(R.string.none_found).toString(); mNewDevicesArrayAdapter.add(noDevices); } }
这边显示的两个字符串。但是,有个点击事件,把这个字符串的后17字符回传,导致出错。
// The on-click listener for all devices in the ListViews private OnItemClickListener mDeviceClickListener = new OnItemClickListener() { public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) { // Cancel discovery because it's costly and we're about to connect mBtAdapter.cancelDiscovery(); // Get the device MAC address, which is the last 17 chars in the View String info = ((TextView) v).getText().toString(); String address = info.substring(info.length() - 17); // Create the result Intent and include the MAC address Intent intent = new Intent(); intent.putExtra(EXTRA_DEVICE_ADDRESS, address); // Set result and finish this Activity setResult(Activity.RESULT_OK, intent); finish(); }
回到上一个aty的处理:
private void connectDevice(Intent data, boolean secure) { // Get the device MAC address String address = data.getExtras().getString(DeviceListActivity.EXTRA_DEVICE_ADDRESS); // Get the BluetoothDevice object BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address); // Attempt to connect to the device mChatService.connect(device, secure); }
很明显,如果是显示"没有找到匹配的字符串" or "未找到设备" ,不是有效的MAC地址。
解决方法:再加一层判断就好了。