Android小程序如何实现简易QQ界面

package com.example.login;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.Toast;
import android.widget.ToggleButton;

public class MainActivity extends Activity {
 //声明组件 
 private EditText username;
 private EditText password;
 private Button login;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  //无标题设置
  requestWindowFeature(Window.FEATURE_NO_TITLE);
  setContentView(R.layout.activity_main);


  //初始化控件，根据Id获取组件对象
  username = (EditText)findViewById(R.id.username);
  password = (EditText)findViewById(R.id.password);
  login = (Button)findViewById(R.id.login);

  //注册监听
  login.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View v) {
    // 登录
    Log.i("tag", "username:"+username.getText().toString());
    Log.i("tag", "password:"+password.getText().toString());
    Toast t1 = Toast.makeText(getApplicationContext(), "登录成功", Toast.LENGTH_LONG);
    t1.show();  
   }
  });
 }
}

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

 <LinearLayout
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="#55000000"
  android:orientation="vertical"
  android:paddingLeft="30dp"
  android:paddingRight="30dp" >

  <LinearLayout
   android:layout_marginTop="80dp"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:gravity="center_vertical"
   android:orientation="horizontal" >

   <ImageView
    android:layout_width="43dp"
    android:layout_height="43dp"
    android:src="@drawable/qq" />

   <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="QQ"
    android:textColor="#fff"
    android:textSize="50dp" />
  </LinearLayout>

  <EditText
   android:id="@+id/username"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_marginTop="30dp"
   android:background="@null"
   android:hint="QQ号/手机号/邮箱"
   android:maxLength="13"
   android:singleLine="true"
   android:textColor="#fff"
   android:textSize="30px"
   android:textColorHint="#eee" />

  <View
   android:layout_width="match_parent"
   android:layout_height="1px"
   android:layout_marginTop="10dp"
   android:background="#eee" />

  <EditText
   android:id="@+id/password"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_marginTop="10dp"
   android:background="@null"
   android:hint="密码"
   android:inputType="textPassword"
   android:maxLength="13"
   android:singleLine="true"
   android:textColor="#fff"
   android:textSize="30px"
   android:textColorHint="#eee" />

  <View
   android:layout_width="match_parent"
   android:layout_height="1px"
   android:layout_marginTop="10dp"
   android:background="#eee" />

  <Button
   android:id="@+id/login"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_marginTop="10dp"
   android:background="@drawable/button_login_bg"
   android:text="登录"
   android:textColor="#fff"
   android:textSize="25px" />

  <LinearLayout
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_marginTop="10dp"
   android:orientation="horizontal" >

   <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:text="忘记密码？"
    android:textColor="#cc1CA4DE"
    android:textSize="20dp" />

   <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:gravity="right"
    android:text="新用户注册"
    android:textColor="#cc1CA4DE"
    android:textSize="20dp" />
  </LinearLayout>
 </LinearLayout>
</LinearLayout>