eclipse for android无法启动活动

Question

我在主菜单页面中有4个按钮，分别是calculate，enter records，view graph和logout。但是，我无法启动图表的活动。我能够运行该程序，只是无法启动图活动，请帮助。

public void GraphHandler (View v)
  {
    {
        Graph line = new Graph();
        Intent lineIntent = line.getIntent(this);
        startActivity(lineIntent);
    }

 }

public void onClick(View v) {


 {      
     switch(v.getId())
     {


  case (R.id.buttonCalculate):
  Intent i = new Intent(this,Calculate.class);
  startActivity(i);
  break;

  case (R.id.buttonRecords):
       Intent f = new Intent(this,Records.class);
       startActivity(f);
       break;


   case (R.id.buttonLogout):
   Intent g = new Intent(this,Logout.class);
   startActivity(g);
   break;

     }
 }