android ：记住密码功能

1. activity_main.xml

1   <TextView
2         android:id="@+id/tvAccount"
3         android:layout_width="wrap_content"
4         android:layout_height="wrap_content"
5         android:layout_alignBaseline="@+id/etAccount"
6         android:layout_alignBottom="@+id/etAccount"
7         android:text="@string/tvAccount"
8         android:textAppearance="?android:attr/textAppearanceLarge" />
9
10     <EditText
11         android:id="@+id/etAccount"
12         android:layout_width="wrap_content"
13         android:layout_height="wrap_content"
14         android:layout_alignParentRight="true"
15         android:layout_alignParentTop="true"
16         android:layout_marginTop="18dp"
17         android:ems="10" />
18
19     <EditText
20         android:id="@+id/etPass"
21         android:layout_width="wrap_content"
22         android:layout_height="wrap_content"
23         android:layout_alignBottom="@+id/tvPass"
24         android:layout_alignLeft="@+id/etAccount"
25         android:ems="10"
26         android:inputType="textPassword" >
27
28         <requestFocus />
29     </EditText>
30
31     <TextView
32         android:id="@+id/tvPass"
33         android:layout_width="wrap_content"
34         android:layout_height="wrap_content"
35         android:layout_alignLeft="@+id/tvAccount"
36         android:layout_below="@+id/etAccount"
37         android:layout_marginTop="29dp"
38         android:text="@string/tvPass"
39         android:textAppearance="?android:attr/textAppearanceLarge" />
40
41     <CheckBox
42         android:id="@+id/cbRemPass"
43         android:layout_width="wrap_content"
44         android:layout_height="wrap_content"
45         android:layout_alignLeft="@+id/tvPass"
46         android:layout_below="@+id/etPass"
47         android:layout_marginTop="20dp"
48         android:text="@string/cbRemPass" />
49
50     <Button
51         android:id="@+id/btnLogin"
52         android:layout_width="wrap_content"
53         android:layout_height="wrap_content"
54         android:layout_alignBottom="@+id/cbRemPass"
55         android:layout_alignRight="@+id/etPass"
56         android:text="@string/btnLogin" />

2. MainActivity.java

主要用了SharedPreferences来保存密码

2.1 定义SharedPreferences

private SharedPreferences mSettings = null;

2.2 button按钮的点击监听事件

1 private void setListener() {
2         // TODO Auto-generated method stub
3         btnLogin.setOnClickListener(new OnClickListener() {
4             public void onClick(View v) {
5                 // TODO Auto-generated method stub
6                 // 判断复选框是否被选中
7                 if (cbRemPass.isChecked()) {
8                     mSettings = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
9                     Editor edit = mSettings.edit();
10                     //标记
11                     edit.putBoolean("isKeep", true);
12                     //记录用户名
13                     edit.putString("username", etAccount.getText().toString());
14                     edit.putString("password", etPass.getText().toString());
15                     edit.commit();
16                 }else{
17                     mSettings = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
18                     Editor edit = mSettings.edit();
19                     //标记
20                     edit.putBoolean("isKeep", true);
21                     //记录用户名
22                     edit.putString("username", "");
23                     edit.putString("password", "");
24                     edit.commit();
25                 }
26             }
27         });
28     }

2.3
第二次启动获取保存的密码的关键代码

1 private void getData() {
2         // TODO Auto-generated method stub
3         mSettings = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
4         if(mSettings.getBoolean("isKeep", false)){
5             etAccount.setText(mSettings.getString("username", ""));
6             etPass.setText(mSettings.getString("password", ""));
7         }else{
8             etAccount.setText("");
9             etPass.setText("");
10         }
11     }