以一个登陆的例子来将，将登陆时的信息保存在指定目录的文件中。在第一次登陆后，对用户名等在内存文件中保存。
android界面：
界面：
1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 2 xmlns:tools="http://schemas.android.com/tools" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" 5 android:orientation="vertical" 6 android:paddingBottom="@dimen/activity_vertical_margin" 7 android:paddingLeft="@dimen/activity_horizontal_margin" 8 android:paddingRight="@dimen/activity_horizontal_margin" 9 android:paddingTop="@dimen/activity_vertical_margin" 10 tools:context=".MainActivity" > 11 12 <TextView 13 android:layout_width="fill_parent" 14 android:layout_height="wrap_content" 15 android:text="@string/PlaseInputName" 16 android:textSize="20dp" 17 /> 18 19 <EditText 20 android:id="@+id/et_username" 21 android:layout_width="fill_parent" 22 android:layout_height="wrap_content" 23 android:layout_marginBottom="20dp" 24 android:textColor="#FFFF00" 25 /> 26 27 <TextView 28 android:layout_width="fill_parent" 29 android:layout_height="wrap_content" 30 android:text="@string/PlaseInputPwd" 31 android:textSize="20dp" /> 32 33 <EditText 34 android:inputType="textPassword" 35 android:id="@+id/et_userpwd" 36 android:layout_width="fill_parent" 37 android:layout_height="wrap_content" /> 38 39 <RelativeLayout 40 android:layout_width="fill_parent" 41 android:layout_height="wrap_content" > 42 43 <CheckBox 44 android:id="@+id/cb_remeber_pwd" 45 android:layout_width="wrap_content" 46 android:layout_height="wrap_content" 47 android:checked="true" 48 android:text="@string/checkpwd" /> 49 50 <Button 51 android:layout_width="wrap_content" 52 android:layout_height="wrap_content" 53 android:layout_alignParentRight="true" 54 android:onClick="login" 55 android:text="@string/login" 56 /> 57 </RelativeLayout> 58 59 </LinearLayout>
界面原型：
在第一次登陆时，看是否选择记住密码，如果是将登陆信息保存后读取
public class LoginService {
public static boolean saveUerInfo(Context context, String UerName,
String password) {
try {
File file = new File(context.getFilesDir(), "info.txt");
// File file = new File("/data/data/com.example.login/info.txt");
FileOutputStream fos = new FileOutputStream(file);
fos.write((UerName + "###" + password).getBytes());
return true;
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
return false;
}
}
主函数：
1 package com.example.login;
2
3 import java.util.Map;
4
5 import com.example.login.service.LoginService;
6
7 import android.os.Bundle;
8 import android.app.Activity;
9 import android.text.TextUtils;
10 import android.view.Menu;
11 import android.view.View;
12 import android.widget.CheckBox;
13 import android.widget.EditText;
14 import android.widget.Toast;
15
16 public class MainActivity extends Activity {
17 private EditText et_username;
18 private EditText et_userpwd;
19 private CheckBox cb;
20
21 @Override
22 protected void onCreate(Bundle savedInstanceState) {
23 super.onCreate(savedInstanceState);
24 setContentView(R.layout.activity_main);
25 et_username = (EditText) this.findViewById(R.id.et_username);
26 et_userpwd = (EditText) this.findViewById(R.id.et_userpwd);
27 cb = (CheckBox) this.findViewById(R.id.cb_remeber_pwd);
28 Map<String, String> map = LoginService.getSaveUserInfo(this);
29 if(map!=null){
30 et_username.setText(map.get("name"));
31 et_userpwd.setText(map.get("password"));
32 }
33 }
34
35 // 登陆
36 public void login(View view) {
37 String name = et_username.getText().toString().trim();
38 String password = et_userpwd.getText().toString().trim();
39 if (TextUtils.isEmpty(name) || (TextUtils.isEmpty(password))) {
40 Toast.makeText(this, "用户名或密码不能为空", Toast.LENGTH_SHORT).show();
41 } else {
42 // 登陆
43 if (cb.isChecked()) {
44 // 保存密码
45 boolean result = LoginService.saveUerInfo(this, name, password);
46 if (result) {
47 Toast.makeText(this, "保存信息成功", 0).show();
48 }
49 }
50 // 登陆
51 if ("zhangsan".equals(name) && ("12345").equals(password)) {
52 Toast.makeText(this, "登陆成功", 0).show();
53 } else {
54 Toast.makeText(this, "登陆失败", 0).show();
55 }
56 }
57 }
58
59 public EditText getEt_username() {
60 return et_username;
61 }
62
63 public void setEt_username(EditText et_username) {
64 this.et_username = et_username;
65 }
66
67 public EditText getEt_userpwd() {
68 return et_userpwd;
69 }
70
71 public void setEt_userpwd(EditText et_userpwd) {
72 this.et_userpwd = et_userpwd;
73 }
74
75 public CheckBox getCb() {
76 return cb;
77 }
78
79 public void setCb(CheckBox cb) {
80 this.cb = cb;
81 }
82
83 }
方法：
1 package com.example.login.service;
2
3 import java.io.BufferedReader;
4 import java.io.File;
5 import java.io.FileInputStream;
6 import java.io.FileNotFoundException;
7 import java.io.FileOutputStream;
8 import java.io.IOException;
9 import java.io.InputStreamReader;
10 import java.util.HashMap;
11 import java.util.Map;
12
13 import org.apache.http.entity.InputStreamEntity;
14
15 import android.content.Context;
16
17 public class LoginService {
18 public static boolean saveUerInfo(Context context, String UerName,
19 String password) {
20
21 try {
22 File file = new File(context.getFilesDir(), "info.txt");
23 // File file = new File("/data/data/com.example.login/info.txt");
24 FileOutputStream fos = new FileOutputStream(file);
25 fos.write((UerName + "###" + password).getBytes());
26 return true;
27 } catch (Exception e) {
28 // TODO Auto-generated catch block
29 e.printStackTrace();
30 return false;
31 }
32
33 }
34
35 public static Map<String, String> getSaveUserInfo(Context context) {
36 try {
37 File file = new File(context.getFilesDir(), "info.txt");
38 FileInputStream fis = new FileInputStream(file);
39 BufferedReader br = new BufferedReader(new InputStreamReader(fis));
40 String str = br.readLine();
41 String[] infos = str.split("###");
42 Map<String, String> map = new HashMap<String, String>();
43 map.put("name", infos[0]);
44 map.put("password", infos[1]);
45 return map;
46 } catch (Exception e) {
47 // TODO Auto-generated catch block
48 e.printStackTrace();
49 }
50 return null;
51
52
53 }
54 }
时间： 2024-12-28 12:01:14