Android應用開發教程之二十四：屏幕鎖定詳解

　　最近在一個視頻項目中遇到了很多屏幕鎖定的問題,自己也在學習,網上找了下也沒太詳細的例子,看的資料書上也沒有有關屏幕鎖定程序的介紹,從之前寫的文章中抽過來放研究院中，希望能幫助更多想了解或學習屏幕鎖的朋友們學習研究,自己照著官方文檔學習下,現在做好了,廢話不多說,先發下截圖,看下效果,需要注意的地方會加注釋,有問題的朋友可以直接留言,我們共同學習交流,共同提高進步!直接看效果圖:

　　一:未設置密碼時進入系統設置的效果圖如下:

　　二:運行DEMO,進入應用時:

　　三:設置密碼方式預覽:

　　四:只設置密碼保護時的效果圖

　　五:密碼解密效果圖

　　六:設置九宮格加密時的效果圖

　　七:九宮格解密時的效果圖

　　八:解密成功後,進入我們手機系統的圖

　　下面來簡單的看下源碼吧,此處講下,這個小DEMO也是臨時學習下的,有講的不明白的地方請朋友直接批評指出,有錯肯定改的,吼吼..看代碼:

　　主控制類:

1. package com.xiaoma.policymanager.demo;   
2.    
3. import android.app.Activity;  
4. import android.app.admin.DevicePolicyManager;  
5. import android.content.Intent;  
6. mport android.content.SharedPreferences;  
7. import android.os.Bundle;  
8. import android.view.View;  
9. import android.widget.AdapterView;  
10. import android.widget.ArrayAdapter;  
11. import android.widget.Button;  
12. import android.widget.EditText;  
13. import android.widget.LinearLayout;  
14. mport android.widget.Spinner;  
15. import android.widget.TextView;   
16.    
17. /** 
18. * @Title: PolicySetupActivity.java 
19. * @Package com.xiaoma.policymanager.demo 
20. * @Description: 屏幕鎖實現測試 
21. * @author MZH 
22. */  
23. public class PolicySetupActivity extends Activity {  
24.     private static final int REQ_ACTIVATE_DEVICE_ADMIN = 10;  
25.     private static final String SCREEN_ID_KEY = "LAYOUT_ID";   
26.    
27.     /**存儲配置信息的SP文件名*/  
28.     private static final String APP_PREF = "APP_PREF";  
29.     /**有未知屏幕ID時返回此標識*/  
30.    private static final int UNKNOWN_SCREEN_ID = -1;   
31.    
32.     /**聲明組件*/  
33.     private Spinner mPasswordQualityInputField;  
34.     private EditText mPasswordLengthInputField;  
35.     private EditText mPasswordMinUppercaseInputField;   
36.    
37.     /**獲取配置操作類對象*/  
38.     private Policy mPolicy;  
39.     /**當前屏幕ID*/  
40.     private int mCurrentScreenId;   
41.    
42.     @Override  
43.     public void onCreate(Bundle savedInstanceState) {  
44.         super.onCreate(savedInstanceState);  
45.         mPolicy = new Policy(this);  
46.     }   
47.    
48.     @Override  
49.     protected void onResume() {  
50.         super.onResume();  
51.         /**獲取本地SP文件中屏幕鎖的配置信息*/  
52.         SharedPreferences prefs = getSharedPreferences(APP_PREF, MODE_PRIVATE);  
53.         final int savedScreenId = prefs.getInt(SCREEN_ID_KEY, UNKNOWN_SCREEN_ID);  
54.         /**如果獲取到的ID為空,則跳轉到設置頁*/  
55.         if (savedScreenId == UNKNOWN_SCREEN_ID || !mPolicy.isAdminActive()) {  
56.             setScreenContent(R.layout.activity_policy_setup);  
57.         /**跳轉到配置詳情頁*/  
58.         } else {  
59.             setScreenContent(savedScreenId);  
60.         }  
61.     }   
62.    
63.    /** 
64.      * 設置屏幕方法實現,詳細的可以自己看下,我也是邊參照官方文檔,邊學習的 
65.      * 有好想法..有問題的朋友們可以留言.我們一起學習 
66.      * @param screenId 
67.      */  
68.     private void setScreenContent(final int screenId) {  
69.         /**記錄當前屏幕ID，並預先存入本地SP配置文件中*/  
70.         mCurrentScreenId = screenId;  
71.         setContentView(mCurrentScreenId);  
72.         getSharedPreferences(APP_PREF, MODE_PRIVATE).edit().putInt(  
73.                 SCREEN_ID_KEY, mCurrentScreenId).commit();  
74.         switch (mCurrentScreenId) {  
75.         case R.layout.activity_policy_setup:  
76.             initPolicySetupScreen();  
77.             initNavigation();  
78.             break;  
79.         case R.layout.activity_view_policy:  
80.             initViewPolicyScreen();  
81.             initNavigation();  
82.             break;  
83.         }  
84.     }   
85.    
86.     /** 
87.      * 關閉頁面時將當前配置寫入本地SP文件中 
88.      */  
89.     @Override  
90.     protected void onPause() {  
91.         super.onPause();  
92.         if (mCurrentScreenId == R.layout.activity_policy_setup) writePolicy();  
93.     }   
94.    
95.    @Override  
96.     protected void onActivityResult(int requestCode, int resultCode, Intent data) {  
97.         if (requestCode == REQ_ACTIVATE_DEVICE_ADMIN && resultCode == RESULT_OK) {  
98.             // User just activated the application as a device administrator.  
99.             setScreenContent(mCurrentScreenId);  
100.         } else {  
101.             super.onActivityResult(requestCode, resultCode, data);  
102.         }  
103.     }   
104.    
105.     /** 
106.      * 重載返回鍵方法,如果已當前屏幕為已設置密碼頁,則展示詳情 
107.      */  
108.     @Override  
109.     public void onBackPressed() {  
110.         if (mCurrentScreenId == R.layout.activity_view_policy) {  
111.             setScreenContent(R.layout.activity_policy_setup);  
112.             return;  
113.         }  
114.         super.onBackPressed();  
115.     }   
116.    
117.     /** 
118.      * 初始化化設置頁 
119.      */  
120.     private void initPolicySetupScreen() {  
121.         mPasswordQualityInputField = (Spinner) findViewById(R.id.policy_password_quality);  
122.         mPasswordLengthInputField = (EditText) findViewById(R.id.policy_password_length);  
123.         mPasswordMinUppercaseInputField = (EditText) findViewById(R.id.policy_password_uppercase);  
124.         ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,  
125.                 R.array.password_types, android.R.layout.simple_spinner_item);  
126.         adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);  
127.         mPasswordQualityInputField.setAdapter(adapter);  
128.         mPasswordQualityInputField.setOnItemSelectedListener(  
129.                 new AdapterView.OnItemSelectedListener() {  
130.             public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {  
131.                 LinearLayout passwordMinUppercaseView =  
132.                         (LinearLayout) findViewById(R.id.password_uppercase_view);  
133.                 // The minimum number of upper case field is only applicable for password  
134.                 // qualities: alpha, alphanumeric, or complex.  
135.                 if (pos > 2)  
136.                     passwordMinUppercaseView.setVisibility(View.VISIBLE);  
137.                 else  
138.                     passwordMinUppercaseView.setVisibility(View.GONE);  
139.             }   
140.    
141.             public void onNothingSelected(AdapterView<?> parent) {}  
142.         });   
143.    
144.         /**閱讀先前配置的相關信息*/  
145.         mPolicy.readFromLocal();  
146.         mPasswordQualityInputField.setSelection(mPolicy.getPasswordQuality());  
147.         if (mPolicy.getPasswordLength() > 0) {  
148.             mPasswordLengthInputField.setText(String.valueOf(mPolicy.getPasswordLength()));  
149.         } else {  
150.             mPasswordLengthInputField.setText("");  
151.         }   
152.    
153.         if (mPolicy.getPasswordMinUpperCase() > 0) {  
154.             mPasswordMinUppercaseInputField.setText(  
155.                     String.valueOf(mPolicy.getPasswordMinUpperCase()));  
156.         } else {  
157.             mPasswordMinUppercaseInputField.setText("");  
158.         }  
159.     }   
160.    
161.     /** 
162.      * 初始化查看詳情頁 
163.      */  
164.     private void initViewPolicyScreen() {  
165.         TextView passwordQualityView = (TextView) findViewById(R.id.policy_password_quality);  
166.         TextView passwordLengthView = (TextView) findViewById(R.id.policy_password_length);   
167.    
168.         // Read previously saved policy and populate on the UI.  
169.         mPolicy.readFromLocal();  
170.         int passwordQualitySelection = mPolicy.getPasswordQuality();  
171.         passwordQualityView.setText(  
172.                 getResources().getStringArray(R.array.password_types)[passwordQualitySelection]);  
173.         passwordLengthView.setText(String.valueOf(mPolicy.getPasswordLength()));  
174.         if (passwordQualitySelection > 2) {  
175.             LinearLayout passwordMinUppercaseView =  
176.                     (LinearLayout) findViewById(R.id.password_uppercase_view);  
177.             passwordMinUppercaseView.setVisibility(View.VISIBLE);  
178.             ((TextView) findViewById(R.id.policy_password_uppercase)).setText(  
179.                     String.valueOf(mPolicy.getPasswordMinUpperCase()));  
180.         }  
181.     }   
182.    
183.     /** 
184.      * 設置導航信息 
185.      */  
186.     private void initNavigation() {  
187.         if (!mPolicy.isAdminActive()) {  
188.             // Activates device administrator.  
189.             setupNavigation(R.string.setup_message_activate,  
190.                     R.string.setup_action_activate,  
191.                     mActivateButtonListener);  
192.         } else if (mCurrentScreenId == R.layout.activity_policy_setup) {  
193.             setupNavigation(R.string.setup_message_set_policy,  
194.                     R.string.setup_action_set_policy,  
195.                     new View.OnClickListener() {  
196.                         public void onClick(View view) {  
197.                             writePolicy();  
198.                             mPolicy.configurePolicy();  
199.                             setScreenContent(R.layout.activity_view_policy);  
200.                         }  
201.                     });  
202.         }  
203.         else if (!mPolicy.isActivePasswordSufficient()) {  
204.             // Launches password set-up screen in Settings.  
205.             setupNavigation(R.string.setup_message_enforce_policy,  
206.                     R.string.setup_action_enforce_policy,  
207.                     mEnforcePolicyListener);  
208.         } else {  
209.             // Grants access to secure content.  
210.             setupNavigation(R.string.setup_message_go_secured,  
211.                     R.string.setup_action_go_secured,  
212.                     new View.OnClickListener() {  
213.                         public void onClick(View view) {  
214.                             startActivity(new Intent(view.getContext(), SecureActivity.class));  
215.                         }  
216.                     });  
217.         }  
218.     }   
219.    
220.     /** 
221.      * 監聽器實現,這個不多講了. 
222.      */  
223.     private View.OnClickListener mActivateButtonListener = new View.OnClickListener() {  
224.         @Override  
225.         public void onClick(View v) {  
226.             // First, persist the policy.  Then, launch intent to trigger the system screen  
227.             // requesting user to confirm the activation of the device administrator.  
228.             writePolicy();  
229.             Intent activateDeviceAdminIntent =  
230.                 new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);  
231.             activateDeviceAdminIntent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN,  
232.                     mPolicy.getPolicyAdmin());  
233.             // It is good practice to include the optional explanation text to explain to  
234.             // user why the application is requesting to be a device administrator.  The system  
235.             // will display this message on the activation screen.  
236.             activateDeviceAdminIntent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION,  
237.                     getResources().getString(R.string.device_admin_activation_message));  
238.             startActivityForResult(activateDeviceAdminIntent, REQ_ACTIVATE_DEVICE_ADMIN);  
239.         }  
240.     };   
241.    
242.     /** 
243.      * 監聽器實現,這個也不多講了. 
244.      */  
245.     private View.OnClickListener mEnforcePolicyListener = new View.OnClickListener() {  
246.         @Override  
247.         public void onClick(View v) {  
248.             writePolicy();  
249.             // The device administration API does not "fix" the password if it is  
250.             // determined that the current password does not conform to what is requested  
251.             // by the policy.  The caller is responsible for triggering the password set up  
252.             // screen via the below intent.  
253.             Intent intent = new Intent(DevicePolicyManager.ACTION_SET_NEW_PASSWORD);  
254.             startActivity(intent);  
255.         }  
256.     };   
257.    
258.     /** 
259.      * 設置激活按鈕不同狀態時的文本信息 
260.      * @param messageResId 
261.      * @param buttonTextResId 
262.      * @param listener 
263.      */  
264.     private void setupNavigation(int messageResId, int buttonTextResId,  
265.             View.OnClickListener listener) {  
266.         TextView setupMessage = (TextView) findViewById(R.id.setup_message);  
267.         setupMessage.setText(messageResId);  
268.         Button actionBtn = (Button) findViewById(R.id.setup_action_btn);  
269.         actionBtn.setText(buttonTextResId);  
270.         actionBtn.setOnClickListener(listener);  
271.     }   
272.    
273.     // 在關閉此頁時，將配置信息寫入本地SP文件中.  
274.     private void writePolicy() {  
275.         int passwordQuality = (int) mPasswordQualityInputField.getSelectedItemId();   
276.    
277.         int passwordLength = 0;  
278.         try {  
279.             passwordLength = Integer.valueOf(mPasswordLengthInputField.getText().toString());  
280.         } catch (NumberFormatException nfe) {}  // Defaults to 0.   
281.    
282.         int passwordMinUppercase = 0;  
283.         try {  
284.             passwordMinUppercase =  
285.                     Integer.valueOf(mPasswordMinUppercaseInputField.getText().toString());  
286.         } catch (NumberFormatException nfe) {}  // Defaults to 0.   
287.    
288.         mPolicy.saveToLocal(passwordQuality, passwordLength, passwordMinUppercase);  
289.     }  
290. }  

　　配置操作類:

1. package com.xiaoma.policymanager.demo;   
2.    
3. import android.app.Activity;  
4. import android.app.admin.DeviceAdminReceiver;  
5. import android.app.admin.DevicePolicyManager;  
6. import android.content.ComponentName;  
7. import android.content.Context;  
8. import android.content.Intent;  
9. import android.content.SharedPreferences;  
10. import android.os.Build;   
11.    
12. /** 
13. * @Title: Policy.java 
14. * @Package com.xiaoma.policymanager.demo 
15. * @Description: 用來獲取相關安全配置信息的類 
16. * @author MZH 
17. */  
18. public class Policy {  
19.     public static final int REQUEST_ADD_DEVICE_ADMIN = 1;   
20.    
21.     /**保存屏幕鎖相關參數的SP文件名*/  
22.     private static final String APP_PREF = "APP_PREF";  
23.     /**下面三個是往SP中存儲時的Key*/  
24.     private static final String KEY_PASSWORD_LENGTH = "PW_LENGTH";  
25.     private static final String KEY_PASSWORD_QUALITY = "PW_QUALITY";  
26.     private static final String KEY_PASSWORD_MIN_UPPERCASE = "PW_MIN_UPPERCASE";   
27.    
28.     /** 
29.      * 下面是可允許輸入密碼的類型,此處的類型必須與string.xml文件中定義的arrays.xml中的相匹配 
30.      */  
31.     final static int[] PASSWORD_QUALITY_VALUES = new int[] {  
32.         DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED,  
33.         DevicePolicyManager.PASSWORD_QUALITY_SOMETHING,  
34.         DevicePolicyManager.PASSWORD_QUALITY_NUMERIC,  
35.         DevicePolicyManager.PASSWORD_QUALITY_ALPHABETIC,  
36.         DevicePolicyManager.PASSWORD_QUALITY_ALPHANUMERIC,  
37.         DevicePolicyManager.PASSWORD_QUALITY_COMPLEX  
38.     };   
39.    
40.     private int mPasswordQuality;  
41.     private int mPasswordLength;  
42.     private int mPasswordMinUpperCase;  
43.     private Context mContext;  
44.     private DevicePolicyManager mDPM;  
45.     private ComponentName mPolicyAdmin;   
46.    
47.     /** 
48.      * 構造器，在new此類對象時，獲取系統級管理員對象 DevicePolicyManager 
49.      * @param context 
50.      */  
51.     public Policy(Context context) {  
52.         mContext = context;  
53.         mPasswordQuality = -1;  
54.         mPasswordLength = 0;  
55.         mPasswordMinUpperCase = 0;  
56.         mDPM = (DevicePolicyManager) context.getSystemService(Context.DEVICE_POLICY_SERVICE);  
57.         mPolicyAdmin = new ComponentName(context, PolicyAdmin.class);  
58.     }   
59.    
60.     /** 
61.      * 保存設備參數 
62.      */  
63.     public void saveToLocal(int passwordQuality, int passwordLength, int passwordMinUppercase) {  
64.         SharedPreferences.Editor editor =  
65.                 mContext.getSharedPreferences(APP_PREF, Context.MODE_PRIVATE).edit();  
66.         if (mPasswordQuality != passwordQuality) {  
67.             editor.putInt(KEY_PASSWORD_QUALITY, passwordQuality);  
68.             mPasswordQuality = passwordQuality;  
69.         }  
70.         if (mPasswordLength != passwordLength) {  
71.             editor.putInt(KEY_PASSWORD_LENGTH, passwordLength);  
72.             mPasswordLength = passwordLength;  
73.         }  
74.         if (mPasswordMinUpperCase != passwordMinUppercase) {  
75.             editor.putInt(KEY_PASSWORD_MIN_UPPERCASE, passwordMinUppercase);  
76.             mPasswordMinUpperCase = passwordMinUppercase;  
77.         }  
78.         editor.commit();  
79.     }   
80.    
81.     /** 
82.      * 從本地SP文件中獲取密碼配置參數 
83.      */  
84.     public void readFromLocal() {  
85.         SharedPreferences prefs = mContext.getSharedPreferences(APP_PREF, Context.MODE_PRIVATE);  
86.         mPasswordQuality = prefs.getInt(KEY_PASSWORD_QUALITY, -1);  
87.         mPasswordLength = prefs.getInt(KEY_PASSWORD_LENGTH, -1);  
88.         mPasswordMinUpperCase = prefs.getInt(KEY_PASSWORD_MIN_UPPERCASE, -1);  
89.     }   
90.    
91.     /** 
92.      * 獲取密碼. 
93.      * 
94.      * @return 
95.      */  
96.     public int getPasswordQuality() { return mPasswordQuality; }   
97.    
98.     /** 
99.      * 獲取密碼長度. 
100.      * 
101.      * @return 
102.      */  
103.     public int getPasswordLength() { return mPasswordLength; }   
104.    
105.     /** 
106.      * 獲取字母密碼. 
107.      * 
108.      * @return 
109.      */  
110.     public int getPasswordMinUpperCase() { return mPasswordMinUpperCase; }   
111.    
112.     /** 
113.      * 獲取設備管理的 ComponentName 對象. 
114.      * 
115.      * @return 
116.      */  
117.     public ComponentName getPolicyAdmin() { return mPolicyAdmin; }   
118.    
119.     /** 
120.      * 判斷設備是否被激活. 
121.      * 
122.      * @return 
123.      */  
124.     public boolean isAdminActive() {  
125.         return mDPM.isAdminActive(mPolicyAdmin);  
126.     }   
127.    
128.     public boolean isActivePasswordSufficient() {  
129.         return mDPM.isActivePasswordSufficient();  
130.     }   
131.    
132.     /** 
133.      * 判斷設備是否加安全 
134.      * @return 
135.      */  
136.     public boolean isDeviceSecured() {  
137.         return isAdminActive() && isActivePasswordSufficient();  
138.     }   
139.    
140.     /** 
141.      * 在聲明的mDPM對象中進行配置. 
142.      */  
143.     public void configurePolicy() {  
144.         mDPM.setPasswordQuality(mPolicyAdmin, PASSWORD_QUALITY_VALUES[mPasswordQuality]);  
145.         mDPM.setPasswordMinimumLength(mPolicyAdmin, mPasswordLength);  
146.         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {  
147.             mDPM.setPasswordMinimumUpperCase(mPolicyAdmin, mPasswordMinUpperCase);  
148.         }  
149.     }   
150.    
151.     /** 
152.      * 下面這個類用來監聽各種不同類型的設備管理事件,比如:改變密碼..錯誤密碼等等 
153.      */  
154.     public static class PolicyAdmin extends DeviceAdminReceiver {   
155.    
156.         @Override  
157.         public void onDisabled(Context context, Intent intent) {  
158.             // Called when the app is about to be deactivated as a device administrator.  
159.             super.onDisabled(context, intent);  
160.             SharedPreferences prefs = context.getSharedPreferences(APP_PREF, Activity.MODE_PRIVATE);  
161.             /**清除以前在SP文件下保存的所有值*/  
162.             prefs.edit().clear().commit();  
163.         }  
164.     }  
165. }  

　　權限驗證類:

1. package com.xiaoma.policymanager.demo;   
2.    
3. import android.app.Activity;  
4. import android.content.Intent;   
5.    
6. /** 
7. * @Title: SecureActivity.java 
8. * @Package com.xiaoma.policymanager.demo 
9. * @Description: 權限驗證類實現 
10. * @author MZH 
11. */  
12. public class SecureActivity extends Activity {   
13.    
14.     @Override  
15.     protected void onResume() {  
16.         super.onResume();  
17.         // Check to see if the device is properly secured as per the policy.  Send user  
18.         // back to policy set up screen if necessary.  
19.         Policy policy = new Policy(this);  
20.         policy.readFromLocal();  
21.         if (!policy.isDeviceSecured()) {  
22.             Intent intent = new Intent();  
23.             intent.setClass(this, PolicySetupActivity.class);  
24.             intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP |  
25.                             Intent.FLAG_ACTIVITY_CLEAR_TASK);  
26.             startActivity(intent);  
27.             finish();  
28.         }  
29.         setContentView(R.layout.activity_secure);  
30.     }  
31. }