android实现仿QQ登陆界面的多账号保存

android应用程序中有些使用到用户账号登录，例如QQ登录，登录界面需要用户输入账号，为了提高用户体验，应该尽量减少用户的输入操作，因此需要将用户登录过的账号保存下来，以供下次使用。保存登录账号是一个小量数据，使用Sharedpreferences或普通文件均可实现。以下程序代码保存用户使用过的5个账号。

程序运行界面：

     

布局文件（/res/layout/main.xml)

<?xml version="1.0" encoding="utf-8"?><RelativeLayout    android:id="@+id/RelativeLayout1"    xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent">    <TextView        android:textAppearance="?android:attr/textAppearanceLarge"        android:layout_height="wrap_content"        android:layout_width="wrap_content"        android:id="@+id/textView1"        android:text="name:"        android:gravity="center"        android:layout_alignParentTop="true"        android:layout_alignParentLeft="true"        android:layout_alignBottom="@+id/name"></TextView>    <EditText        android:layout_height="wrap_content"        android:layout_width="wrap_content"        android:id="@+id/name"        android:layout_alignParentTop="true"        android:layout_alignParentRight="true"        android:layout_toRightOf="@+id/textView2">        <requestFocus></requestFocus>    </EditText>    <TextView        android:textAppearance="?android:attr/textAppearanceLarge"        android:layout_height="wrap_content"        android:layout_width="wrap_content"        android:id="@+id/textView2"        android:text="password:"        android:layout_below="@+id/name"        android:layout_alignParentLeft="true"></TextView>    <EditText        android:layout_height="wrap_content"        android:layout_width="wrap_content"        android:id="@+id/password"        android:layout_alignTop="@+id/textView2"        android:layout_alignParentRight="true"        android:layout_alignLeft="@+id/name"></EditText>    <Button        android:layout_height="wrap_content"        android:layout_width="wrap_content"        android:id="@+id/button2"        android:text="Button"        android:layout_below="@+id/password"        android:layout_toLeftOf="@+id/button1"></Button>    <Button        android:layout_height="wrap_content"        android:layout_width="wrap_content"        android:id="@+id/button1"        android:text="Button"        android:layout_alignBaseline="@+id/button2"        android:layout_alignBottom="@+id/button2"        android:layout_alignParentRight="true"        android:layout_marginRight="20dp"></Button>    <ImageView        android:layout_width="wrap_content"        android:src="@drawable/array_down"        android:layout_height="wrap_content"        android:id="@+id/show"        android:layout_alignParentTop="true"        android:layout_alignParentRight="true"        android:layout_alignBottom="@+id/name"></ImageView></RelativeLayout>

java源文件(MainActivity.java)

import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.util.ArrayList;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.ViewGroup;import android.view.View.OnClickListener;import android.widget.AdapterView;import android.widget.ArrayAdapter;import android.widget.EditText;import android.widget.ImageView;import android.widget.ListView;import android.widget.PopupWindow;import android.widget.AdapterView.OnItemClickListener;import android.widget.PopupWindow.OnDismissListener;public class MainActivity extends Activity implementsOnClickListener, OnItemClickListener, OnDismissListener {private ArrayList<String> mList = new ArrayList<String>();private EditText mEditText;private ImageView mImageView;private PopupWindow mPopup;private boolean mShowing;private ArrayAdapter<String> mAdapter;private ListView mListView;private boolean mInitPopup;/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);mEditText = (EditText) findViewById(R.id.name);mImageView = (ImageView) findViewById(R.id.show);mImageView.setOnClickListener(this);init();}private void init() {ObjectInputStream in = null;try {InputStream is = openFileInput("account.obj");in = new ObjectInputStream(is);mList = (ArrayList<String>) in.readObject();if (mList.size() > 0) {mEditText.setText(mList.get(mList.size() - 1));}} catch (Exception e) {e.printStackTrace();} finally {if (in != null) {try {in.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}}@Overrideprotected void onDestroy() {super.onDestroy();String input = mEditText.getText().toString();mList.remove(input);mList.add(input);if (mList.size() > 5) {mList.remove(0);}ObjectOutputStream out = null;try {FileOutputStream os = openFileOutput("account.obj",MODE_PRIVATE);out = new ObjectOutputStream(os);out.writeObject(mList);} catch (Exception e) {} finally {if (out != null) {try {out.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}}@Overridepublic void onClick(View v) {if (v.getId() == R.id.show) {if(mList!=null && mList.size()>0 && !mInitPopup){mInitPopup = true;initPopup();}if (mPopup != null) {if (!mShowing) {mPopup.showAsDropDown(mEditText,0,-5);mShowing = true;} else {mPopup.dismiss();}}}}private void initPopup() {mAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_dropdown_item_1line, mList);mListView = new ListView(this);mListView.setAdapter(mAdapter);mListView.setOnItemClickListener(this);int height = ViewGroup.LayoutParams.WRAP_CONTENT;int width = mEditText.getWidth();System.out.println(width);mPopup = new PopupWindow(mListView, width, height, true);mPopup.setOutsideTouchable(true);mPopup.setBackgroundDrawable(getResources().getDrawable(R.drawable.popup_bg));mPopup.setOnDismissListener(this);}@Overridepublic void onItemClick(AdapterView<?> parent, View view,int position, long id) {mEditText.setText(mList.get(position));mPopup.dismiss();}@Overridepublic void onDismiss() {mShowing = false;}}

 

感谢fyqjnu提供的支持和帮助 ！