Android 输入字符输出ascii码，编译没有关问题但是运行时崩溃

Android 输入字符输出ascii码，编译没问题但是运行时崩溃

public class Activity1 extends Activity {
	 
	public static int char2ASCII(char c) {   
         return (int) c;   
     }   
	 public static int[] string2ASCII(String s) {// 字符串转换为ASCII码   
	        if (s == null || "".equals(s)) {   
	            return null;   
	        }   
	  
	        char[] chars = s.toCharArray();   
	        int[] asciiArray = new int[chars.length];   
	  
	        for (int i = 0; i < chars.length; i++) {   
	            asciiArray[i] = char2ASCII(chars[i]);   
	        }   
	        return asciiArray;   
	    }   
	@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_activity1);
         
        Button button1=(Button)this.findViewById(R.id.button1);
        final EditText editText1=(EditText)findViewById(R.id.editText1);
        
        
        
        button1.setOnClickListener(new OnClickListener()
        {
        	public void onClick(View arg0)
        	{ 
        	    String a=editText1.getText().toString();
        		Intent intentRef=new Intent();
        		intentRef.setClass(Activity1.this, Activity2.class);
        		
        		Bundle bundle = new Bundle();
        		bundle.putIntArray("a", string2ASCII(a));
        		intentRef.putExtras(bundle);
        		
        		startActivity(intentRef);
        		Activity1.this.finish();
        	}
        }
        		);
    }
}

public class Activity2 extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_activity2);
        
        Bundle bundle = this.getIntent().getExtras();
        int[] b = bundle.getIntArray("a");
        int c= b[0]%10;
        
        TextView textview =(TextView) findViewById(R.id.textView1);
        textview.setText(c) ;
    }
}

------解决方案--------------------
异常那行：textview.setText(""+c) ;或textview.setText(Intege.valueOf(c)) ;
------解决方案--------------------
编译出现问题，说资源文件有问题