Android开发--按钮开启线程导致程序闪退 求大神帮忙看看

[numberer]

就是想实现一个音乐播放器的功能，button1（ btn1 )对应的播放按钮。我的想法是点击button1运行线程。但是实际上我运行时点击播放之后app就闪退了，有没有大神帮忙看一下。

package com.example.angry;


import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
import android.widget.ImageView;
import android.view.View.OnClickListener;
import android.widget.*;
import android.widget.SeekBar;

public class MainActivity extends ActionBarActivity {

	int flag,stop;
	private int i=0;
	SeekBar seekbar;
	myThread music;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		Button btn3=(Button)findViewById(R.id.button3);
		Button btn1=(Button)findViewById(R.id.button1);
		Button btn2=(Button)findViewById(R.id.button2);
		Button btn4=(Button)findViewById(R.id.button4);
		Button btn5=(Button)findViewById(R.id.button5);
		seekbar=(SeekBar)findViewById(R.id.seek07);
		seekbar.setMax(10);
		btn1.setOnClickListener(new myClick2());
		btn2.setOnClickListener(new myClick3());
		btn3.setOnClickListener(new myClick1());
		btn4.setOnClickListener(new myClick4());
		btn5.setOnClickListener(new myClick4());
		flag=0;
		seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {  
                 i=progress;
            }  
            public void onStartTrackingTouch(SeekBar seekBar){	}  
            public void onStopTrackingTouch(SeekBar seekBar) {	}  
        });
		}
		class myClick1 implements OnClickListener{
			public void onClick(View v){
				Button btn1=(Button)findViewById(R.id.button3);
				if(flag==0){
					btn1.setBackgroundResource(R.drawable.laopo1);
					flag=1;
				}
				else{
					btn1.setBackgroundResource(R.drawable.laopo);
					flag=0;
				}
			}
		}
		class myClick2 implements OnClickListener{
			public void onClick(View v){
				seekbar.setMax(10);
				stop=0;
				music.start();
			}
		}
		class myClick3 implements OnClickListener{
			public void onClick(View v){
				stop=1;
			}
		}
		class myClick4 implements OnClickListener{
			public void onClick(View v){
				seekbar.setProgress(0);
			}
		}
		class myThread extends Thread{
			public void run(){
				while(i<10)
				{
					try{ 
						sleep(1000);
						}catch (InterruptedException e) { 
							return;
					}
					i++;
					seekbar.incrementProgressBy(1);
					if(stop==1)
						break;
				}
			}
		}
}

[江三木洛]

myThread music; 没有初始化，为空