void bondStateChangeCallback(int status, byte[] address, int newState) { BluetoothDevice device = mRemoteDevices.getDevice(address); if (device == null) { infoLog("No record of the device:" + device); // This device will be added as part of the BONDING_STATE_CHANGE intent processing // in sendIntent above device = mAdapter.getRemoteDevice(Utils.getAddressStringFromByte(address)); } infoLog("bondStateChangeCallback: Status: " + status + " Address: " + device + " newState: " + newState); Message msg = obtainMessage(BONDING_STATE_CHANGE); msg.obj = device; if (newState == BOND_STATE_BONDED) { msg.arg1 = BluetoothDevice.BOND_BONDED; } else if (newState == BOND_STATE_BONDING) { msg.arg1 = BluetoothDevice.BOND_BONDING; } else { msg.arg1 = BluetoothDevice.BOND_NONE; } msg.arg2 = status; sendMessage(msg); }sendMessage(msg);再次发出去是同步还是异步发出去的,如果是异步的话,是否有时序的风险
时间: 2024-02-14 17:26:16 浏览: 23
根据给出的代码片段,sendMessage(msg)方法是在bondStateChangeCallback()回调函数内部调用的。根据Android消息机制,sendMessage()方法通常是异步的,消息会被放入消息队列中,然后在适当的时机被处理。因此,sendMessage()方法的调用是异步的。
关于时序风险,如果在sendMessage()方法调用之后立即对msg进行修改或者释放,则可能存在时序风险。因为消息处理可能会在稍后的时间点才会被执行,而修改或释放msg的操作可能会在消息处理之前发生,导致不一致的结果。为了避免时序风险,应该在sendMessage()之后不要对msg进行修改或释放操作。
相关问题
BluetoothDevice device = BluetoothAdapter.getRemoteDevice("20:22:06:15:35:96");中的getRemoteDevice报错
getRemoteDevice() 方法会抛出一个受检查异常 BluetoothDeviceNotFoundException,需要进行异常处理。可以使用 try-catch 块或者在方法声明中使用 throws 关键字。例如:
```
try {
BluetoothDevice device = BluetoothAdapter.getRemoteDevice("20:22:06:15:35:96");
} catch (BluetoothDeviceNotFoundException e) {
// 处理异常
}
```
或者:
```
public void yourMethod() throws BluetoothDeviceNotFoundException {
BluetoothDevice device = BluetoothAdapter.getRemoteDevice("20:22:06:15:35:96");
}
```
需要注意的是,BluetoothAdapter.getRemoteDevice() 方法需要传入一个合法的蓝牙设备地址。如果传入的地址不合法或者设备不可用,会抛出 BluetoothDeviceNotFoundException 异常。
解释代码private final BroadcastReceiver receiver = new BroadcastReceiver() { public void onReceive(Context context, Intent intent) { boolean f = true; String action = intent.getAction(); BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); if (BluetoothDevice.ACTION_FOUND.equals(action) && f) { addDeviceList(new BleDevice(device, 20, device.getName())); } } };
这段代码定义了一个私有的BroadcastReceiver对象,当接收到蓝牙设备发现的广播时,会执行onReceive()方法。其中,通过getAction()方法获取广播的action,通过getParcelableExtra()方法获取BluetoothDevice对象,判断广播的action是否为ACTION_FOUND,如果是则将获取到的设备信息添加到设备列表中。此外,f变量的作用是控制只有第一次接收到广播时才添加设备信息。
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