我想在子线程的子类中向UI线程发送消息更新界面.
首先成功了一个小例子：
mainActivity{
Handler h = new
@Override
public void handleMessage(Message msg){
一堆更新UI操作...
};
Runnable r = new Runnable() {
@Override
public void run() {
subclass s = new subclass(h);
subclass.do();
}
};
protected void onCreate(Bundle savedInstanceState).......
}
public class subclass{
public Handler mh;
public subclass (Handler h){
mh = h;
}
public void do(){
Message msg = mh.obtainMessage();
msg.sendToTarget();
}
}
但是我将子类subclass换成SurfaceView，构造器为
public SurfaceView(Context context, Handler h) {mh = h}
然后在CALLBACK 的surfaceCreated中向主线程传递消息时报错
public void surfaceCreated(SurfaceHolder holder) {
Message msg = mh.obtainMessage();
msg.sendToTarget();
}
错误提示为： Can't create handler inside thread that has not called Looper.prepare()
问题发生在构造子类时就出错了，位置：
主类：
mPreview = new SurfaceView(MainActivity.this, h);
子类：
public SurfaceView(Context context, Handler h) {mh = h}
请问是咋回事啊
