andriod 错误：Only the original thread that created a view hierarchy can touch its views——Handler的使用

package com.example.yanlei.myapplication;

import android.media.MediaMetadataRetriever;
import android.media.MediaPlayer;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.VideoView;
import android.app.Activity;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.media.MediaPlayer.OnErrorListener;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.Toast;
import android.widget.VideoView;
import android.widget.SeekBar.OnSeekBarChangeListener;

import java.io.File;
import java.util.HashMap;

import android.os.Handler;

private Handler handler = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

seekBar = (SeekBar) findViewById(R.id.seekBar);

// 为进度条添加进度更改事件
seekBar.setOnSeekBarChangeListener(change);

//创建属于主线程的handler
handler = new Handler();

}

protected void play(int msec) {
Log.i(TAG, " 获取视频文件地址");
String path = et_path.getText().toString().trim();
File file = new File(path);
if (!file.exists()) {
Toast.makeText(this, "视频文件路径错误", 0).show();
return;
}

Log.i(TAG, "指定视频源路径");
vv_video.setVideoPath(file.getAbsolutePath());
Log.i(TAG, "开始播放");
vv_video.start();

// 按照初始位置播放
vv_video.seekTo(msec);
// 设置进度条的最大进度为视频流的最大播放时长
final int time = getTimeLong(file.getAbsolutePath()) / 100;
seekBar.setMax(time);
Toast.makeText(this, "长度:" + time, Toast.LENGTH_LONG).show();
// 开始线程，更新进度条的刻度
new Thread() {

@Override
public void run() {
try {
isPlaying = true;
while (isPlaying) {
// 如果正在播放，0.1.毫秒更新一次进度条
final int current = vv_video.getCurrentPosition() / 100;
seekBar.setProgress(current);
/*   try {
myText = "总时间：" + time / 10 + "秒,目前：" + current / 10 + "秒";
// pTextView.setText("总时间：" + time / 10 + "秒,目前：" + current / 10 + "秒");
new WorkThread().start();
} catch (Exception ex) {

Log.d("错误:", ex.getMessage().toString());
}*/

new Thread() {
public void run() {
myText = "总时间：" + time / 10 + "秒,目前：" + current / 10 + "秒";
handler.post(updateUIRunnable);
}
}.start();

//Toast.makeText(this, "当前:"+current,Toast.LENGTH_LONG).show();
sleep(100);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}.start();
// 播放之后设置播放按钮不可用
btn_play.setEnabled(false);

vv_video.setOnCompletionListener(new OnCompletionListener() {

@Override
public void onCompletion(MediaPlayer mp) {
// 在播放完毕被回调
btn_play.setEnabled(true);
}
});

vv_video.setOnErrorListener(new OnErrorListener() {

@Override
public boolean onError(MediaPlayer mp, int what, int extra) {
// 发生错误重新播放
play(0);
isPlaying = false;
return false;
}
});
}

//工作线程
private class WorkThread extends Thread {
@Override
public void run() {
try {

pTextView.setText(myText);
} catch (Exception ex) {
Log.e("严重错误:", ex.getMessage().toString());

}
}
}

// 构建Runnable对象，并在runnable中更新UI
Runnable updateUIRunnable = new Runnable() {
@Override
public void run() {
try {

pTextView.setText(myText);
} catch (Exception ex) {
Log.e("严重错误:", ex.getMessage().toString());

}
}
};