Get what parameter from Handler.obtainMessage()

问题:

I am using a Thread to do some BT tasks. I am trying to send a message to the UI thread so I can do UI work based on my BT thread. To do this I am using a Handler, but I don't know how to retrive the data that I send to my Handler.

To send data i use:

handler.obtainMessage(intCode).sendToTarget();

Where intCode is an int. My Handler looks like this.

Handler handler = new Handler(){
    @Override
    public void handleMessage(Message msg){
        Bundle data = msg.getData();
        int code = data.getInt("what");
        Log.d(LOG_TAG, "Msg: "+code);
    }
}

But the value of code is never anything else than 0. How do i get the value sent when doing .obtainMessage(int)? Is the value not stored in a Bundle with the key "what"?

回答1:

You can set data in this format

While setting data

Message msg = new Message();
msg.obj = data which you want to set // for object data
Msg.arg1  = data which you want to set // for integer data

While getting data

String data = (String) msg.obj; // If object is of String
int integerData = msg.arg1;

msg.arg1 will pass only one data at a time you can also pass data in msg.arg2 they both are of integer types

回答2:

You can get Message data under the param Message in public boolean handleMessage(Message message). For example, to get arg1 in message, you can just:

mHandler = new Handler(this.getLooper(), new Handler.Callback() {

        @Override
        public boolean handleMessage(Message message) {
            switch (message.what){
                case MY_MESSAGE_1:
                    int argument1 = message.arg1;
                    return true;
                    ....