是的,问题出在按钮声明中,写下代码而不是代码,它将解决您的问题.

public class Menu extends Activity implements OnClickListener{

Button loginbutton, recordbutton, viewbutton, projectsbutton;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.menu);

loginbutton = (Button) findViewById(R.id.butlogin);

loginbutton.setOnClickListener(this);

recordbutton = (Button) findViewById(R.id.butrecordts);

recordbutton.setOnClickListener(this);

viewbutton = (Button) findViewById(R.id.butviewts);

viewbutton.setOnClickListener(this);

projectsbutton = (Button) findViewById(R.id.butprojects);

projectsbutton.setOnClickListener(this);

}

public void onClick(View v){

switch(v.getId())

{

case R.id.butlogin:

{

//open login screen

Intent i = new Intent(this, login.class);

startActivity(i);

break;

}

case R.id.butrecordts:

{

break;

}

case R.id.butviewts:

{

break;

}

case R.id.butprojects:

{

break;

}

}

}

}