1.沿用java的子线程创建
private void createNewThread(){
//1.用继承Thread的方式创建子线程，耦合性比较大
MyNewThread thread=new MyNewThread();
thread.start();
//2.用Runnable的方式创建子线程
MyThread mThread=new MyThread();
Thread myThread=new Thread(mThread);
myThread.start();
//3.用匿名内部类的方式创建子线程
new Thread(new Runnable() {
@Override
public void run() {
Log.d("csc","正在用匿名内类方式创建子线程，当前线程的id为"+Thread.currentThread().getId());
}
}).start();
}
class MyNewThread extends Thread{
@Override
public void run() {
super.run();
Log.d("csc","正在用继承Thread方式创建子线程，当前线程的id为"+Thread.currentThread().getId());
}
}
class MyThread implements Runnable{@Override
public void run() {
Log.d("csc","正在用接口实现方式创建子线程，当前线程的id为"+Thread.currentThread().getId());
}
}
2.在子线程中不能更新UI，那么在Android中更新UI的方法
private static final int UPDATE_TEXT=1;
Handler handler=new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what){
case UPDATE_TEXT:
textChange.setText("我在这儿等着你回来");
break;
}
}
};
private TextView textChange;
Message message=new Message();
message.what=UPDATE_TEXT;
handler.sendMessage(message);
runOnUiThread内部的原理也是使用了handler来处理。
【Android多线程】3.AsyncTask的使用
class DownloadTask extends AsyncTask{
@Override
protected void onPreExecute() {
//执行任务前调用
Log.d("csc","在执行耗时操作之前被调用");
}@Override
protected Object doInBackground(Object[] params) {
//这里进行耗时操作
for (int i=0;
i<10;
i++){
try {
Thread.sleep(2000);
Log.d("csc","正在执行第"+(i+1)+"次耗时操作");
publishProgress((i+1)*10);
} catch (InterruptedException e) {
e.printStackTrace();
return false;
}
}
return true;
}@Override
protected void onProgressUpdate(Object[] values) {
//对UI进行更新操作,调用publishProgress()得到执行
Toast.makeText(ThreadActivity.this,"当前进度是"+values[0],Toast.LENGTH_SHORT).show();
Log.d("csc","当前进度是"+values[0]);
}@Override
protected void onPostExecute(Object o) {
//执行任务后调用
boolean result=(boolean)o;
if (result){
Log.d("csc","耗时任务已经执行完毕");
Toast.makeText(ThreadActivity.this,"耗时任务已经执行完毕",Toast.LENGTH_SHORT).show();
}else {
Log.d("csc","任务执行失败");
Toast.makeText(ThreadActivity.this,"任务执行失败",Toast.LENGTH_SHORT).show();
}
}
}
new DownloadTask().execute();
