本文实例讲述了Android开发之完成登陆界面的数据保存回显操作。分享给大家供大家参考，具体如下：
LoginActivity.java：
package com.example.login;
import java.util.Map;
import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;
import com.example.login.service.FileService;
public class LoginActivity extends Activity {
public EditText edit_name,edit_pass;
public Button btn_login;
public CheckBox box_remeber;
public FileService fileService;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
fileService=new FileService(this);
edit_name=(EditText) findViewById(R.id.edit_name);
edit_pass=(EditText) findViewById(R.id.edit_pass);
btn_login=(Button) findViewById(R.id.btn_login);
box_remeber=(CheckBox) findViewById(R.id.cbx_remember);
btn_login.setOnClickListener(new MyOnClickListener());
Map<String, String> map=fileService.readFile("private.txt");
if(map!=null){
edit_name.setText(map.get("name"));
edit_pass.setText(map.get("pass"));
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.login, menu);
return true;
}
class MyOnClickListener implements View.OnClickListener{
@Override
public void onClick(View v) {
int id=v.getId();
switch (id) {
case R.id.btn_login:
String name=edit_name.getText().toString();
String pass=edit_pass.getText().toString();
if(TextUtils.isEmpty(name)){
Toast.makeText(LoginActivity.this, "用户名不能为空", Toast.LENGTH_SHORT).show();
return;
}else if(TextUtils.isEmpty(pass)){
Toast.makeText(LoginActivity.this, "密码不能为空", Toast.LENGTH_SHORT).show();
return;
}else{
if(box_remeber.isChecked()){
LoginActivity.this.fileService.saveToRom(name, pass, "private.txt");
Toast.makeText(LoginActivity.this, "用户名和密码已保存", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(LoginActivity.this, "用户名和密码不需要保存", Toast.LENGTH_SHORT).show();
}
}
break;
default:
break;
}
/*if(id==btn_login.getId()){
String name=edit_name.getText().toString();
String pass=edit_pass.getText().toString();
if(TextUtils.isEmpty(name)){
Toast.makeText(LoginActivity.this, "用户名不能为空", Toast.LENGTH_SHORT).show();
return;
}else if(TextUtils.isEmpty(pass)){
Toast.makeText(LoginActivity.this, "密码不能为空", Toast.LENGTH_SHORT).show();
return;
}else{
if(box_remeber.isChecked()){
LoginActivity.this.fileService.saveToRom(name, pass, "private.txt");
Toast.makeText(LoginActivity.this, "用户名和密码已保存", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(LoginActivity.this, "用户名和密码不需要保存", Toast.LENGTH_SHORT).show();
}
}
}*/
}
}
}
FileService.java：
package com.example.login.service;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.HashMap;
import java.util.Map;
import com.example.login.utils.StreamTools;
import android.content.Context;
public class FileService {
public Context context;
public FileService(Context context) {
this.context = context;
}
public boolean saveToRom(String name,String pass,String fileName){
try{
FileOutputStream fos=context.openFileOutput(fileName, Context.MODE_PRIVATE);
String result=name+":"+pass;
fos.write(result.getBytes());
fos.flush();
fos.close();
}catch(Exception e){
e.printStackTrace();
return false;
}
return true;
}
public Map<String,String> readFile(String fileName){
Map<String,String> map=null;
try{
FileInputStream fis=context.openFileInput(fileName);
String value=StreamTools.getValue(fis);
String values[]=value.split(":");
if(values.length>0){
map=new HashMap<String, String>();
map.put("name", values[0]);
map.put("pass", values[1]);
}
}catch(Exception e){
e.printStackTrace();
}
return map;
}
}
StreamTools.java：
package com.example.login.utils;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
public class StreamTools {
public static String getValue(FileInputStream fis) throws Exception{
ByteArrayOutputStream stream=new ByteArrayOutputStream();
byte[] buffer=new byte[1024];
int length=-1;
while((length=fis.read(buffer))!=-1){
stream.write(buffer,0,length);
}
stream.flush();
stream.close();
String value=stream.toString();
return value;
}
}
login_activity.xml：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".LoginActivity" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/view_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/text_name" />
<EditText
android:id="@+id/edit_name"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:inputType="textPersonName">
<requestFocus />
</EditText>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/view_pass"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/text_pass" />
<EditText
android:id="@+id/edit_pass"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:inputType="textPassword" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<Button
android:id="@+id/btn_login"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="0.17"
android:text="@string/text_login" />
<CheckBox
android:id="@+id/cbx_remember"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="80dp"
android:text="@string/text_rember" />
</LinearLayout>
</LinearLayout>
</RelativeLayout>
String.xml：
<?xmlversion="1.0"encoding="utf-8"?> <resources> <stringname="app_name">login</string> <stringname="action_settings">Settings</string> <stringname="hello_world">Login</string> <stringname="text_name">用户名:</string> <stringname="text_pass">密 码:</string> <stringname="text_login">登陆</string> <stringname="text_rember">记住密码</string> </resources>
希望本文所述对大家Android程序设计有所帮助。
