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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