Android耗时操作,我们可以通过几种方式实现:
IntentService
IntentService 与Service的不同之处在于IntentService是可以执行耗时任务的,而Service不能够执行耗时任务,否则会出现ANR异常。
IntentService的用法:
创建一个自定义的IntentService:
public class TestService extends IntentService {
public TestService(){
super("");
}
@Override
protected void onHandleIntent(@Nullable Intent intent) {
try {
Log.d("tag","start onHandleIntent");
// 可以执行耗时任务
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public IBinder onBind(Intent intent){
return super.onBind(intent);
}
public int onStartCommand(Intent intent, int flags, int startId){
return super.onStartCommand(intent,flags,startId);
}
public void setIntentRedelivery(boolean enabled){
super.setIntentRedelivery(enabled);
}
public void onDestroy(){
super.onDestroy();
}
}
在AndroidManifest注册IntentService:
<service android:name=".TestService"/>
调用IntentService:
Intent intent = new Intent(MainActivity.this,TestService.class);
startService(intent);
HandlerThread
HandlerThread是一个包含了Looper的Thread,我们可以直接使用这个Looper创建Handler。
使用起来非常简单:
HandlerThread mHandlerThread = new HandlerThread("test-handler-thread");
mHandlerThread.start();
Handler mHandler = new Handler(mHandlerThread.getLooper()){
public void handleMessage(Message msg){
while(true){
try {
Thread.sleep(2000);
Log.d("tag","" + (int)(Math.random() * 100));
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
};
mHandler.sendEmptyMessage(0);
AsyncTask
实现AsyncTask:
// 启动时的参数,中间过程的百分比,完成后返回的结果
public class UpdateAsyncTask extends AsyncTask<Integer, Integer, Integer> {
private TextView textView;
public UpdateAsyncTask(TextView textView) {
super();
this.textView = textView;
}
@Override
protected Integer doInBackground(Integer... integers) {
try {
int i = 0;
while (true) {
Thread.sleep(500);
publishProgress(i++);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
return 1;
}
protected void onPreExecute() {
Log.d("tag", "开始执行");
}
protected void onProgressUpdate(Integer... values) {
textView.setText("" + values[0]);
}
protected void onPostExecute(Integer result) {
textView.setText("" + result);
textView = null;
}
}
创建AsyncTask并执行:
new UpdateAsyncTask(textView).execute();