使用SharedPreferences存储用户名信息

 1 package com.example.sharedpreferences;

 2 

 3 import android.os.Bundle;

 4 import android.preference.PreferenceManager;

 5 import android.app.Activity;

 6 import android.content.SharedPreferences;

 7 import android.content.SharedPreferences.Editor;

 8 import android.view.Menu;

 9 import android.view.View;

10 import android.view.View.OnClickListener;

11 import android.widget.Button;

12 import android.widget.CheckBox;

13 import android.widget.EditText;

14 import android.widget.TextView;

15 import android.widget.Toast;

16 

17 public class MainActivity extends Activity implements OnClickListener{

18     private EditText et1,et2;

19     private CheckBox cb1;

20     private Button bt1,bt2;

21     private SharedPreferences pref;

22     private Editor editor;

23     private TextView tv1;

24     @Override

25     protected void onCreate(Bundle savedInstanceState) {

26         super.onCreate(savedInstanceState);

27         setContentView(R.layout.activity_main);

28 //        SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(this);

29 //        SharedPreferences pref = getSharedPreferences("mypref", MODE_PRIVATE);

30 //        Editor editor = pref.edit();

31 //        editor.putString("name", "阿狸");

32 //        editor.putLong("time", System.currentTimeMillis());

33 //        editor.commit();

34 //        System.out.println(pref.getString("name", ""));

35 //        System.out.println(pref.getLong("time", 0));

36         

37         et1 = (EditText) findViewById(R.id.editText1);

38         et2 = (EditText) findViewById(R.id.editText2);

39         cb1 = (CheckBox) findViewById(R.id.checkBox1);

40         bt1 = (Button) findViewById(R.id.button1);

41         bt2 = (Button) findViewById(R.id.button2);

42         tv1 = (TextView) findViewById(R.id.textView1);

43         bt1.setOnClickListener(this);

44         bt2.setOnClickListener(this);

45         pref = getSharedPreferences("mypref1", MODE_PRIVATE);

46         editor = pref.edit();

47         String name = pref.getString("username", "");

48         if(name == null) {

49             cb1.setChecked(false);

50         }else{

51             cb1.setChecked(true);

52             et1.setText(name);

53         }

54     }

55 

56     @Override

57     public void onClick(View v) {

58         // TODO Auto-generated method stub

59         switch (v.getId()) {

60         case R.id.button1:

61             String name = et1.getText().toString().trim();

62             String pass = et2.getText().toString().trim();

63             if(name.equals("admin")&&pass.equals("123456")){

64                 if(cb1.isChecked()){

65                     editor.putString("username", "admin");

66                     editor.commit();

67                 }else {

68                     editor.remove("username");

69                     editor.commit();

70                 }

71                 Toast.makeText(MainActivity.this, "登陆成功！", Toast.LENGTH_SHORT).show();

72             }else{

73                 Toast.makeText(MainActivity.this, "登陆失败！", Toast.LENGTH_SHORT).show();

74             }

75             break;

76         case R.id.button2:

77             

78             break;

79         }

80     }

81     

82 }

上面是MainActivity的代码，下面是UI的代码。

 1 <RelativeLayout 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     tools:context=".MainActivity" >

 6 

 7     <TextView

 8         android:id="@+id/textView1"

 9         android:layout_width="wrap_content"

10         android:layout_height="wrap_content"

11         android:layout_alignParentLeft="true"

12         android:layout_alignParentTop="true"

13         android:layout_marginLeft="17dp"

14         android:layout_marginTop="18dp"

15         android:text="用户名：" />

16 

17     <EditText

18         android:id="@+id/editText1"

19         android:layout_width="wrap_content"

20         android:layout_height="wrap_content"

21         android:layout_alignBaseline="@+id/textView1"

22         android:layout_alignBottom="@+id/textView1"

23         android:layout_alignRight="@+id/button2"

24         android:layout_toRightOf="@+id/textView1"

25         android:ems="10" >

26 

27         <requestFocus />

28     </EditText>

29 

30     <TextView

31         android:id="@+id/textView2"

32         android:layout_width="wrap_content"

33         android:layout_height="wrap_content"

34         android:layout_alignLeft="@+id/textView1"

35         android:layout_below="@+id/editText1"

36         android:layout_marginTop="14dp"

37         android:text="密码：" />

38 

39     <EditText

40         android:id="@+id/editText2"

41         android:layout_width="wrap_content"

42         android:layout_height="wrap_content"

43         android:layout_alignLeft="@+id/editText1"

44         android:layout_alignRight="@+id/editText1"

45         android:layout_below="@+id/editText1"

46         android:ems="10"

47         android:inputType="textPassword" />

48 

49     <CheckBox

50         android:id="@+id/checkBox1"

51         android:layout_width="wrap_content"

52         android:layout_height="wrap_content"

53         android:layout_alignLeft="@+id/textView2"

54         android:layout_below="@+id/editText2"

55         android:layout_marginTop="16dp"

56         android:checked="false"

57         android:text="保存" />

58 

59     <Button

60         android:id="@+id/button1"

61         android:layout_width="wrap_content"

62         android:layout_height="wrap_content"

63         android:layout_alignLeft="@+id/checkBox1"

64         android:layout_below="@+id/checkBox1"

65         android:layout_marginTop="14dp"

66         android:text="确定" />

67 

68     <Button

69         android:id="@+id/button2"

70         android:layout_width="wrap_content"

71         android:layout_height="wrap_content"

72         android:layout_alignBaseline="@+id/button1"

73         android:layout_alignBottom="@+id/button1"

74         android:layout_alignParentRight="true"

75         android:layout_marginRight="26dp"

76         android:text="取消" />

77 

78 </RelativeLayout>

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