简单的文本数据写入文件不需要权限，读写SD卡在4.0版本前需要写权限、在4.0后需要读写权限
布局：
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="wrap_content" 5 android:orientation="vertical" 6 tools:context=".MainActivity" > 7 8 <EditText android:id="@+id/et_number" 9 android:layout_width="fill_parent" 10 android:layout_height="wrap_content" 11 android:phoneNumber="true" 12 android:hint="请输入手机号" /> 13 14 <EditText 15 android:id="@+id/et_pwd" 16 android:layout_width="fill_parent" 17 android:layout_height="match_parent" 18 android:hint="请输入密码" 19 android:inputType="textPassword" /> 20 21 <CheckBox android:id="@+id/cb_remerber_pwd" 22 android:layout_width="wrap_content" 23 android:layout_height="wrap_content" 24 android:checked="true" 25 android:text="记住密码" /> 26 27 <Button android:id="@+id/btn_Login" 28 android:layout_width="wrap_content" 29 android:layout_height="wrap_content" 30 android:text="登陆" 31 /> 32 33 </LinearLayout>
Manifest.xml添加权限
1 <!-- 写入外部设备(sdka)的权限 --> 2 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 3 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
MainActivity：
1 public class MainActivity extends Activity implements OnClickListener {
2 private static final String TAG = "MainActivity";
3 private EditText etNumber;
4 private EditText etPwd;
5 private CheckBox cbRemerber;
6
7 @Override
8 protected void onCreate(Bundle savedInstanceState) {
9 super.onCreate(savedInstanceState);
10 setContentView(R.layout.activity_main);
11 //获取控件中数据
12 etNumber = (EditText)findViewById(R.id.et_number);
13 etPwd=(EditText)findViewById(R.id.et_pwd);
14 cbRemerber=(CheckBox)findViewById(R.id.cb_remerber_pwd);
15 Button btnLogin = (Button)findViewById(R.id.btn_Login);
16 //添加点击事件
17 btnLogin.setOnClickListener(this);
18 //获取SD卡数据
19 Map<String,String> userInfo=UtilsOfSDCard.getUserInfo(this);
20 if(userInfo!=null){
21 etNumber.setText(userInfo.get("number"));
22 etPwd.setText(userInfo.get("pwd"));
23 }
24 }
25
26 @Override
27 public void onClick(View v) {
28 // TODO Auto-generated method stub
29 //1.取出账号，密码
30 String Number=etNumber.getText().toString();
31 String Pwd=etPwd.getText().toString();
32 //判断是否有值，弹出吐司
33 if(TextUtils.isEmpty(Number) || TextUtils.isEmpty(Pwd)){
34 Toast.makeText(this, "请正确数据账号、密码", Toast.LENGTH_SHORT).show();
35 return;
36 }
37 //2.判断cb是否被选中
38 if(cbRemerber.isChecked()){
39 Log.i(TAG, "记住密码"+Number+","+Pwd);
40 boolean isSuccess=UtilsOfSDCard.saveUserInfo(this,Number, Pwd);
41 if(isSuccess)
42 Toast.makeText(this, "保存成功", Toast.LENGTH_SHORT).show();
43 else
44 Toast.makeText(this, "保存失败", Toast.LENGTH_SHORT).show();
45 }
46
47 //3.登陆成功
48 Toast.makeText(this, "登陆成功", Toast.LENGTH_SHORT).show();
49 }
50
51
52 }
UtilsOfSDCard类：
1 public class UtilsOfSDCard {
2 //保存信息到sd卡
3 public static boolean saveUserInfo(Context context, String number,String pwd){
4 try {
5 //获取SD卡状态
6 String state=Environment.getExternalStorageState();
7 //判断SD卡状态
8 if(!Environment.MEDIA_MOUNTED.equals(state))
9 {
10 return false;
11 }
12 //动态获取SD卡路径
13 File sdCardFile = Environment.getExternalStorageDirectory();
14 File f=new File(sdCardFile,"qqLogin1.txt");
15 //写入流
16 FileOutputStream fos=new FileOutputStream(f);
17
18 String data=number+"##"+pwd;
19 fos.write(data.getBytes());
20 fos.flush();
21 fos.close();
22 return true;
23 } catch (Exception e) {
24 // TODO Auto-generated catch block
25 e.printStackTrace();
26 }
27
28 return false;
29 }
30
31 //返回信息
32 public static Map<String,String> getUserInfo(Context context){
33 try {
34 String state=Environment.getExternalStorageState();
35 if(!Environment.MEDIA_MOUNTED.equals(state))
36 {
37 return null;
38 }
39 File sdCartFile=Environment.getExternalStorageDirectory();
40 File f=new File(sdCartFile,"qqLogin1.txt");
41 BufferedReader br=new BufferedReader(new InputStreamReader(new FileInputStream(f)));
42 String text=br.readLine();
43 br.close();
44 if(!TextUtils.isEmpty(text)){
45 Map<String,String> userInfoMap=new HashMap<String,String>();
46 String[] split = text.split("##");
47 userInfoMap.put("number", split[0]);
48 userInfoMap.put("pwd", split[1]);
49 Log.w("UtilsOfSDCard", split[0]+","+split[1]);
50 return userInfoMap;
51 }
52
53 } catch (Exception e) {
54 // TODO Auto-generated catch block
55 e.printStackTrace();
56 }
57
58 return null;
59 }
60 }
Utils类：
1 public class Utils {
2 /*
3 * 保存用户信息
4 * */
5 public static boolean saveUserInfo(String number,String pwd){
6
7 try {
8 String path="/data/data/com.cui.qqlogin/QQLogin.txt";
9 //写入流
10 FileOutputStream fs=new FileOutputStream(path);
11 String data=number+"##"+pwd;
12 fs.write(data.getBytes());
13 fs.flush();
14 fs.close();
15 return true;
16 } catch (Exception e) {
17 // TODO Auto-generated catch block
18 e.printStackTrace();
19 }
20
21 return false;
22 }
23
24 public static boolean saveUserInfo(Context context, String number,String pwd){
25
26 try {
27 //动态获取文件路径
28 File filesDir = context.getFilesDir();
29 File f=new File(filesDir,"QQLogin.txt");
30 //写入流
31 FileOutputStream fs=new FileOutputStream(f);
32 String data=number+"##"+pwd;
33 fs.write(data.getBytes());
34 fs.flush();
35 fs.close();
36 return true;
37 } catch (Exception e) {
38 // TODO Auto-generated catch block
39 e.printStackTrace();
40 }
41
42 return false;
43 }
44
45 public static Map<String,String> getUserInfo(){
46 try {
47 String path="/data/data/com.cui.qqlogin/QQLogin.txt";
48 //输出流
49 FileInputStream fis=new FileInputStream(path);
50 //字符流
51 BufferedReader reader=new BufferedReader(new InputStreamReader(fis));
52 String text = reader.readLine();
53 if(!TextUtils.isEmpty(text)){
54 String[] split=text.split("##");
55 Map<String,String> userofMap=new HashMap<String,String>();
56 userofMap.put("number", split[0]);
57 userofMap.put("pwd", split[1]);
58 return userofMap;
59 }
60
61 } catch (Exception e) {
62 // TODO Auto-generated catch block
63 e.printStackTrace();
64 }
65
66 return null;
67 }
68
69 public static Map<String,String> getUserInfo(Context context){
70 try {
71 //String path="/data/data/com.cui.qqlogin/QQLogin.txt";
72 //动态获取文件路径
73 File filesDir = context.getFilesDir();
74 File f=new File(filesDir,"QQLogin.txt");
75 //输出流
76 FileInputStream fis=new FileInputStream(f);
77 //字符流
78 BufferedReader reader=new BufferedReader(new InputStreamReader(fis));
79 String text = reader.readLine();
80 reader.close();
81 if(!TextUtils.isEmpty(text)){
82 String[] split=text.split("##");
83 Map<String,String> userofMap=new HashMap<String,String>();
84 userofMap.put("number", split[0]);
85 userofMap.put("pwd", split[1]);
86 return userofMap;
87 }
88
89 } catch (Exception e) {
90 // TODO Auto-generated catch block
91 e.printStackTrace();
92 }
93
94 return null;
95 }
96 }
时间： 2024-10-08 02:13:05