主进程更新UI： 会阻塞

MainActivity.java Java文件

package com.example.hongweipc.first;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.button1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    Thread.sleep(1000);
                    System.out.println(">>>>>>>>>>>>>>>>>>>Tick");
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        });
    }
}

activity_main.xml 布局文件

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context="com.example.hongweipc.first.MainActivity">


    <Button
        android:id="@+id/button1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Button"
        tools:layout_editor_absoluteX="45dp"
        android:layout_marginTop="82dp"
        app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.hongweipc.first">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

运行情况

与上面代码只有MainActivity.java文件有修改
线程更新UI：不会阻塞

package com.example.hongweipc.first;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.button1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new Thread() {

                    @Override
                    public void run() {

                        try {
                            while (true) {
                                sleep(1000);
                                System.out.println(">>>>>>>>>>>>>>>>>>>Tick");
                            }
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                }.start();
            }
        });

    }
}

线程运行情况