使用Handler（Looper，Handler.Callback）構(gòu)造函數(shù)并顯式指定循環(huán)器。

情景一：如果您希望代碼在main/UI thread上運(yùn)行

Handler handler = new Handler(Looper.getMainLooper(), new Handler.Callback() {

? ? @Override? ? public boolean handleMessage(@NonNullMessage message) {

? ? ? ? // Your code

??????????return true;

? ? }

});

情景二：如果你想讓代碼在后臺(tái)運(yùn)行thread

// Create a background thread that has a Looper

HandlerThread handlerThread = new HandlerThread("HandlerThread");

handlerThread.start();

// Using this handler to post tasks that running on a background thread.

Handler handler = new Handler(handlerThread.getLooper(), new Handler.Callback() {

? ? @Override? ? public boolean handleMessage(@NonNullMessage message) {

? ? ? ? // Your code

????????????return true;

? ? }

});

釋放thread：handlerThread.quit();或者 handlerThread.quitSafely();

情景三：如果希望代碼在后臺(tái)thread上運(yùn)行，并將結(jié)果返回main/UI thread

// Using this handler to post tasks that run on main/UI thread

Handler uiHandler = new Handler(Looper.getMainLooper());

// Create a background thread that has a LooperHandler

Thread handlerThread = new HandlerThread("HandlerThread");

handlerThread.start();

// Using this handler to post task that run on a background?

threadHandler handler = new Handler(handlerThread.getLooper(), new Handler.Callback() {

? ? @Override? ??

????public boolean handleMessage(@NonNullMessage message) {

? ? ? ? // Execute the code or pass the result back to main/UI thread? ? ? ??

????????????uiHandler.post(new Runnable() {

? ? ? ? ? ? @Override? ? ? ? ? ?

?????????????public void run() {

? ? ? ? ? ? }

? ? ? ? });

? ? ? ? return true;

? ? }

});