问题描述
我想从 GUI 线程设置一个 HandlerThread.然后一段时间后，当单击 GUI 上的按钮时，它会运行 callHello()，然后将消息发送到驻留在异步记录Hello World"的非 GUI 线程上的 HelloLogger 对象.我已经尝试了很多东西，一些无限期地阻止，一些永远不会收到消息等等.下面的代码或多或少与我得到的一样接近，请有人修改它以使其工作吗?
I want to set up a HandlerThread from the GUI thread. Then some time later, when a button is clicked on the GUI, it runs callHello(), which then send a message to a HelloLogger object residing on the non-GUI thread which asynchronously logs "Hello World". I have tried a number of things, some block indefinitely, some never receive the message, etc etc. The code below is more or less as close as I have got, please could someone modify it to work?
public class HandlerThreadExample {
private MyHandlerThread mMyHandlerThread;
private Looper mLooper;
private Handler mHandler;
public HandlerThreadExample(){
mMyHandlerThread = new MyHandlerThread();
mMyHandlerThread.start();
mLooper = mMyHandlerThread.getLooper();
}
public void callHello() {
mHandler.sendEmptyMessage(1);
}
private class MyHandlerThread extends HandlerThread {
private HelloLogger mHelloLogger;
private Handler mHandler;
public MyHandlerThread() {
super("The MyHandlerThread thread", HandlerThread.NORM_PRIORITY);
}
public void run (){
mHelloLogger = new HelloLogger();
mHandler = new Handler(getLooper()){
public void handleMessage(Message msg){
mHelloLogger.logHello();
}
};
super.run();
}
}
private class HelloLogger {
public HelloLogger (){
}
public void logHello(){
Log.d("HandlerThreadExample", "Hello World");
}
}
}
找到的最佳示例:
- HandlerThread 测试
- 如何创建 Looper线程，然后立即向其发送消息?
- 使用处理程序进行异步调用
- HandlerThread 与 Executor - 何时为一比另一个更合适?
- 与其他类似类相比，HandlerThread 的最佳使用
- Android HandlerThread
- HandlerThread 示例
- Android:在 main 和 worker 之间传递数据线程
- Java 同步
- 使用活动线程队列和Handler类在线程之间发送消息
- Loopers 和处理程序介绍
- developer.android:指定在线程上运行的代码
至少现在我可以关闭该死的标签
At least now I can close the damned tabs
解决方案由 pskink 提供帮助
public class HandlerThreadExample2 {
private static int MSG_START_HELLO = 0;
private static int MSG_HELLO_COMPLETE = 1;
private HandlerThread ht;
private Handler mHtHandler;
private Handler mUiHandler;
private boolean helloReady = false;
public HandlerThreadExample2(){
ht = new HandlerThread("The new thread");
ht.start();
Log.d(App.TAG, "UI: handler thread started");
mUiHandler = new Handler(){
public void handleMessage(Message msg){
if (msg.what == MSG_HELLO_COMPLETE){
Log.d(App.TAG, "UI Thread: received notification of sleep completed ");
helloReady = true; }
}
};
mHtHandler = new Handler(ht.getLooper()){
public void handleMessage (Message msg){
if (msg.what == MSG_START_HELLO){
Log.d(App.TAG, "handleMessage " + msg.what + " in " + Thread.currentThread() + " now sleeping");
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
Log.d(App.TAG, "Woke up, notifying UI thread...");
mUiHandler.sendEmptyMessage(MSG_HELLO_COMPLETE);
}
}
};
}
public void sendLongHello(){
if (helloReady){
Log.d(App.TAG, "sending hello " + Thread.currentThread());
mHtHandler.sendEmptyMessage(MSG_START_HELLO);
helloReady = false;
} else {
Log.e(App.TAG, "Cannot do hello yet - not ready");
}
}
}
推荐答案
这是一个工作示例:
HandlerThread ht = new HandlerThread("MySuperAwesomeHandlerThread");
ht.start();
Handler h = new Handler(ht.getLooper()) {
public void handleMessage(Message msg) {
Log.d(TAG, "handleMessage " + msg.what + " in " + Thread.currentThread());
};
};
for (int i = 0; i < 5; i++) {
Log.d(TAG, "sending " + i + " in " + Thread.currentThread());
h.sendEmptyMessageDelayed(i, 3000 + i * 1000);
}
更新:
制作两个类字段:
Handler mHtHandler;
Handler mUiHandler;
试试这个:
HandlerThread ht = new HandlerThread("MySuperAwsomeHandlerThread");
ht.start();
Callback callback = new Callback() {
@Override
public boolean handleMessage(Message msg) {
if (msg.what == 0) {
Log.d(TAG, "got a meaasage in " + Thread.currentThread() + ", now sleeping... ");
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
Log.d(TAG, "woke up, notifying ui thread...");
mUiHandler.sendEmptyMessage(1);
} else
if (msg.what == 1) {
Log.d(TAG, "got a notification in " + Thread.currentThread());
}
return false;
}
};
mHtHandler = new Handler(ht.getLooper(), callback);
mUiHandler = new Handler(callback);
mHtHandler.sendEmptyMessageDelayed(0, 3000);
你当然可以去掉 Callback 接口并使用重写的 handleMessage 方法创建两个处理程序...
You can of course get rid of Callback interface and create two Handlers with overridden handleMessage method...
这篇关于与 HandlerThread 通信的示例的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！