个人练习：更新UI线程

1.如果是同一个线程（或者是主线程）里，可以直接进行UI内容的更新，如果是两个不同的线程，更新则会报错，可以用Handler+Runnable来进行不同线程的UI更新

报错代码（报错内容：ERROR/AndroidRuntime(785): android.view.ViewRoot$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.）：

public class MainActivity extends Activity
{
    private TextView tvInfo = null;
    private Button btnClick = null;
    
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        tvInfo = (TextView)findViewById(R.id.tv01);
        btnClick = (Button)findViewById(R.id.btnClick);
        
        
        
        btnClick.setOnClickListener(new OnClickListener()
        {
            
            @Override
            public void onClick(View v)
            {
                new Thread(run).start();
            }
        });
    }
    Runnable run = new Runnable()
    {
        
        @Override
        public void run()
        {
            tvInfo.setText("kelei");
        }
    };
}

正确代码1：因为是同一个线程（主线成，所以能直接更改UI上的内容）

public class MainActivity extends Activity
{
    private TextView tvInfo = null;
    private Button btnClick = null;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        tvInfo = (TextView) findViewById(R.id.tv01);
        btnClick = (Button) findViewById(R.id.btnClick);

        btnClick.setOnClickListener(new OnClickListener()
        {

            @Override
            public void onClick(View v)
            {
                tvInfo.setText("kelei");
            }
        });
    }
}

正确代码2（使用Handler+Runnable）：

public class MainActivity extends Activity
{
    private TextView tvInfo = null;
    private Button btnClick = null;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        tvInfo = (TextView) findViewById(R.id.tv01);
        btnClick = (Button) findViewById(R.id.btnClick);

        btnClick.setOnClickListener(new OnClickListener()
        {

            @Override
            public void onClick(View v)
            {
                Handler handler = new Handler();
                handler.post(run);
            }
        });
    }
    Runnable run = new Runnable()
    {
        
        @Override
        public void run()
        {
            // TODO Auto-generated method stub
            tvInfo.setText("kelei");
        }
    };
}