android - 打开蓝牙并等待 Intent ？

Question

我有一个 Android 应用程序需要一些蓝牙设置；见下文:

if (!Constants.mBluetoothAdapter.isEnabled()) {
    Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
while (!Constants.mBluetoothAdapter.isEnabled()) {
    try {
        Thread.sleep(100);
    } catch (InterruptedException e) {
        System.exit(1);
    }
}
if (Constants.mBluetoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
    Intent discoverableIntent = new
        Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
        discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 0);
        startActivity(discoverableIntent);
}
while (Constants.mBluetoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
    try {
        Thread.sleep(100);
    } catch (InterruptedException e) {
        System.exit(1);
    }
} // do some stuff with bluetooth

这对我来说似乎是一个 hack，只有在用户选择"is"时它才有效。我很确定我需要等待这些 Intent 的结果。这是怎么做到的？

Answer 1

您可以调用startActivityForResult()并实现onActivityResult()当用户从被调用的 Activity 返回时将被调用的方法。

要检查蓝牙是否启用，请将代码更改为:

if (!Constants.mBluetoothAdapter.isEnabled()) {
    Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
} else {
    progressToNextCheck();
}

然后在 progressNextCheck() 中以类似的方式执行蓝牙可发现性检查。

private void progressToNextCheck(){
    if (Constants.mBluetoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
        Intent discoverableIntent = new        Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
        discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 0);
        startActivityForResult(discoverableIntent, REQUEST_DISCOVERABLE_BT);
    } else {
        goToTheTask();
    }
}

还有你的onActivityResult() 方法:

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
     if (requestCode == REQUEST_ENABLE_BT) {
         if (resultCode == RESULT_OK) {
             progressToNextCheck();
         }
     } else if (requestCode == REQUEST_DISCOVERABLE_BT) {
         if (resultCode == RESULT_OK) {
             goToTheTask();
         }
     }
 }