标签：turn res textview ctas ble exec 直接 cal android
我们经常会在后台线程中去做一些耗时的操作，比如去网络取数据。但是当数据取回来，需要显示到页面上的时候，会遇到一些小麻烦，因为我们都知道，android的UI页面是不允许在其他线程直接操作的。下面总结4中方法用来在线程中操作UI界面。
private void connectNet() throws InterruptedException { Thread.sleep(2000); }
子线程中通过Handler的sendMessage（msg）发送事件：
private void method1() { new Thread(new Runnable() { @Override public void run() { try { //耗时操作 connectNet(); //向Handler发送消息 mHadndler.sendEmptyMessage(111); } catch (InterruptedException e) { e.printStackTrace(); } } }).start(); }
private void method2() { myText.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { new Thread(new Runnable() { @Override public void run() { try { //耗时操作 connectNet(); myText.post(new Runnable() { @Override public void run() { myText.setText("联网结束，更新UI数据"); } }); } catch (InterruptedException e) { e.printStackTrace(); } } }).start(); } }); }
与view.post类似
private void method3() { new Thread(new Runnable() { @Override public void run() { try { //耗时操作 connectNet(); runOnUiThread(new Runnable() { @Override public void run() { myText.setText("runOnUiThread..."); } }); } catch (InterruptedException e) { e.printStackTrace(); } } }).start(); }
private void method4() { //UI线程中执行 new LoadTask().execute("www.91dota.com"); } private class LoadTask extends AsyncTask { protected void onPostExecute(String result) { myText.setText(result); //得到来自网络的信息刷新页面 } protected String doInBackground(Object[] objects) { return "......";//后台耗时操作 } }
===========================》
MainActivity.java
public class MainActivity extends AppCompatActivity { private TextView myText; private Handler mHadndler = new Handler() { @Override public void handleMessage(Message msg) { super.handleMessage(msg); myText.setText("收到消息啦..." + msg.what); } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); myText = findViewById(R.id.myTextView); } /** * 方法一：Handler */ private void method1() { new Thread(new Runnable() { @Override public void run() { try { //耗时操作 connectNet(); //向Handler发送消息 mHadndler.sendEmptyMessage(111); } catch (InterruptedException e) { e.printStackTrace(); } } }).start(); } /** * 方法二：通过View.post(Runnable) */ private void method2() { myText.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { new Thread(new Runnable() { @Override public void run() { try { //耗时操作 connectNet(); myText.post(new Runnable() { @Override public void run() { myText.setText("联网结束，更新UI数据"); } }); } catch (InterruptedException e) { e.printStackTrace(); } } }).start(); } }); } /** * 方法三：Activity.runOnUiThread（Runnable ) */ private void method3() { runOnUiThread(new Runnable() { @Override public void run() { try { //耗时操作 connectNet(); myText.setText("runOnUiThread..."); } catch (InterruptedException e) { e.printStackTrace(); } } }); } /** * 方法四：AsyncTask */ private void method4() { //UI线程中执行 new LoadTask().execute("www.91dota.com"); } private class LoadTask extends AsyncTask { protected void onPostExecute(String result) { myText.setText(result); //得到来自网络的信息刷新页面 } protected String doInBackground(Object[] objects) { return "......";//后台耗时操作 } } private void connectNet() throws InterruptedException { Thread.sleep(2000); } }
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <TextView android:id="@+id/myTextView" android:layout_width="match_parent" android:layout_height="50dp" android:layout_margin="10dp" android:background="#dea" android:gravity="center" android:text="Hello World!" /> </LinearLayout>
参考：http://www.it165.net
标签：turn res textview ctas ble exec 直接 cal android
原文地址：https://www.cnblogs.com/jooy/p/8999200.html
