Android 说明文档明确指出不能在非UI线程直接更新UI线程的信息，否则系统会抛出类似如下异常：
09-15 21:37:09.335: E/AndroidRuntime(4507): android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
文档建议使用Handler+Thread实现异步线程的UI更新，但是在日常工作中，突然发现在非UI线程居然可以直接更新UI信息，当时令我非常惊讶。
这是一个见证奇迹的旅程，请跟随我的思路，为你揭开Android非UI线程直接更新UI信息的神秘面纱！
以下是简单的代码验证（MainActivity.java）：
package com.jony.update.ui;import android.os.Bundle;import android.app.Activity;import android.app.ProgressDialog;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.view.Menu;import android.widget.Button;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.TextView;public class MainActivity extends Activity {private TextView message;private ProgressDialog pd;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);message = (TextView) findViewById(R.id.message);pd = ProgressDialog.show(this, "Title", "Loading…");// Main thread IDSystem.out.println("Main Thread ID—>" + Thread.currentThread().getId());new Thread(){@Overridepublic void run() {// Sub thread IDSystem.out.println("Sub Thread ID—>" + Thread.currentThread().getId());LinearLayout layout = (LinearLayout) message.getParent();// Change the text viewmessage.setBackgroundColor(0Xffbbcc);message.setText(getResources().getString(R.string.update_content));message.setText("Hello jony");message.setTextSize(32);// Add text viewTextView add_view = new TextView(getApplicationContext());add_view.setText(getResources().getString(R.string.update_content));add_view.setTextSize(25);add_view.setText("Change content");// Add image viewImageView imageView = new ImageView(getApplicationContext());Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);imageView.setImageBitmap(bitmap);layout.addView(add_view);layout.addView(imageView);try {Thread.sleep(2000);} catch (InterruptedException e) {e.printStackTrace();}//Button button = new Button(getApplicationContext());//button.setText("commit");//layout.addView(button);pd.dismiss();}}.start();}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {getMenuInflater().inflate(R.menu.activity_main, menu);return true;}}
以上代码片段开启了一个非UI线程，并在该线程中直接更新UI信息。经过运行测试，能够正常运行，证明了在非ＵＩ线程可以直接更新ＵＩ信息。My God，正不是和Google官方文档说的互相矛盾吗？猜想——难道这是Google大神的Bug？
当解除上述代码片段的注释部分：
Button button = new Button(getApplicationContext());button.setText("commit");layout.addView(button);
再次运行以上测试代码，系统会抛出如下异常：
09-15 22:17:34.371: E/WindowManager(6248): Activity com.jony.update.ui.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@414250a0 that was originally added here
简单说明一下以上异常，以上异常信息描述的大概是——MainActivity窗口已经泄露，证明MainActivity已经被finish()或者是被销毁了
既然找到问题所在了，那我们就要证明一下是不是在执行以下代码的时候，MainActivity已经被系统finish了？
layout.addView(button);
简单更改一下以上代码，更改后的代码如下所示（MainActivity）：
package com.jony.update.ui;import android.os.Bundle;import android.app.Activity;import android.app.ProgressDialog;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.view.Menu;import android.widget.Button;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.TextView;public class MainActivity extends Activity {private TextView message;private ProgressDialog pd;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);message = (TextView) findViewById(R.id.message);pd = ProgressDialog.show(this, "Title", "Loading…");// Main thread IDSystem.out.println("Main Thread ID—>" + Thread.currentThread().getId());new Thread(){@Overridepublic void run() {// Sub thread IDSystem.out.println("Sub Thread ID—>" + Thread.currentThread().getId());LinearLayout layout = (LinearLayout) message.getParent();// Change the text viewmessage.setBackgroundColor(0Xffbbcc);message.setText(getResources().getString(R.string.update_content));message.setText("Hello jony");message.setTextSize(32);// Add text viewTextView add_view = new TextView(getApplicationContext());add_view.setText(getResources().getString(R.string.update_content));add_view.setTextSize(25);add_view.setText("Change content");// Add image viewImageView imageView = new ImageView(getApplicationContext());Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);imageView.setImageBitmap(bitmap);layout.addView(add_view);layout.addView(imageView);try {Thread.sleep(2000);} catch (InterruptedException e) {e.printStackTrace();}pd.dismiss();Button button = new Button(getApplicationContext());button.setText("commit");System.out.println("Tha MainActivity is finished?");layout.addView(button);System.out.println("Yes,It is.");}}.start();}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {getMenuInflater().inflate(R.menu.activity_main, menu);return true;}@Overrideprotected void onPause() {// TODO Auto-generated method stubsuper.onPause();System.out.println("onPause");}@Overrideprotected void onStop() {// TODO Auto-generated method stubsuper.onStop();System.out.println("onStop");}@Overrideprotected void onDestroy() {// TODO Auto-generated method stubsuper.onDestroy();System.out.println("onDestroy");}}分明是比谁记的都清楚，比谁都更加在意，
