활동에서 조각을 호출하는 방법

활동에서 조각 클래스를 호출해야합니다. 활동에서 조각 클래스를 호출하기 전에 사용자 이름과 암호를 확인해야합니다. 로그인 버튼을 클릭하면 프래그먼트 클래스가로드되어야합니다. 그러나 로그인 레이아웃은 조각 레이아웃과 겹칩니다. 겹침을 제거하는 방법.

login.java

public class Login extends Activity {

    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            getFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment()).commit();
        } 
    }



  public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.login, container,
                    false);

             return rootView;
        }

        public void onStart(){
            super.onStart();


               final Button loginButton = (Button) getActivity().findViewById(R.id.loginButton);

              loginButton.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    EditText editText1 = (EditText) getActivity().findViewById(R.id.editText1);
                      EditText editText2 = (EditText) getActivity().findViewById(R.id.editText2);
                      final String username = editText1.getText().toString();
                      final String password = editText2.getText().toString();

                     if (username.equals("user") && password.equals("user")){

                          Fragment1 fragment1 = new Fragment1();

                          getFragmentManager().beginTransaction()
                          .replace(android.R.id.content, fragment1).commit();

                         }       
                }
              });


}


    }
}

Fragment1.java

public class Fragment1 extends Fragment{
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState){
return inflater.inflate(R.layout.fragment1, container,false);

}}

login.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<LinearLayout android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="fill_parent">
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"        
android:text="Username" />
<EditText
android:id="@+id/editText1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10" >

<requestFocus />
</EditText>
</LinearLayout>
<LinearLayout android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="fill_parent">
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"        
android:text="Password" />
<EditText
android:id="@+id/editText2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10" >

</EditText>
</LinearLayout>

<Button
android:id="@+id/login"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Login" />

</LinearLayout>

fragment1.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<Button
android:id="@+id/login"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="goto"
android:text="Go to Main Activity" />

</LinearLayout>