Android二维码功能实现

经过我的测试，在ZXing项目中直接导入core-2.2的Jar包是无法正常运行的，所以我们只能通过将core-2.2的源码加入到ZXing项目中来实现。下载好以上两个文件后，先解压core-2.2-sources.jar文件，解压之后的目录结构如下图所示：

                                    

然后解压ZXing-2.2这个压缩包，里面可以看到各种平台下的ZXing项目源码，我们进入到android文件夹的src目录下，将core-2.2-sources中的源码拷贝进来。拷贝之后android文件夹下的目录结构如下图所示：

                          

这样准备工作已经完成了，现在我们新建一个Android项目ScannerTest，项目使用Android 4.0的API。

然后将上图中src目录下的所有文件全部复制，粘贴到我们ScannerTest项目的src目录下，完成后目录结构如下图所示：

                           

拷贝完了代码，现在该拷贝资源了，展开ZXing项目android文件夹下的res目录，将drawable文件夹、layout文件夹、menu文件夹、raw文件夹、values文件夹以及xml文件夹中的内容都拷贝到ScannerTest项目的res目录下，注意有冲突的部分要小心解决，比如两个values文件夹中都有string.xml文件，要将它们的内容进行合并，不能只是简单地覆盖。

然后我们还需要将AndroidManifest中的内容进行合并，注意ZXing Android项目下的AndroidManifest在声明Activity时用的都是简写，而现在由于项目包名变了，再使用简写会出现找不到活动的情况，因此所有的简写都要改成完整类名，例如.CaptureActivity要改成com.google.zxing.client.android.CaptureActivity。另外ZXing Android项目下的主活动是CaptureActivity，这里我们需要将主活动的声明删除掉，因为ScannerTest项目中主活动是MainActivity。合并后的AndroidManifest中的代码如下所示：

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2. <?xmlversion="1.0"encoding="utf-8"?> 
3. <manifest xmlns:android="http://schemas.android.com/apk/res/android" 
4.     package="com.example.scannertest" 
5.     android:versionCode="1" 
6.     android:versionName="1.0"> 
7.  
8.     <uses-permissionandroid:name="android.permission.CAMERA"/> 
9.     <uses-permissionandroid:name="android.permission.INTERNET"/> 
10.     <uses-permissionandroid:name="android.permission.VIBRATE"/> 
11.     <uses-permissionandroid:name="android.permission.FLASHLIGHT"/> 
12.     <uses-permissionandroid:name="android.permission.READ_CONTACTS"/> 
13.     <uses-permissionandroid:name="com.android.browser.permission.READ_HISTORY_BOOKMARKS"/> 
14.     <uses-permissionandroid:name="android.permission.WRITE_EXTERNAL_STORAGE"/> 
15.     <uses-permissionandroid:name="android.permission.CHANGE_WIFI_STATE"/> 
16.     <uses-permissionandroid:name="android.permission.ACCESS_WIFI_STATE"/> 
17.  
18.     <uses-sdk 
19.         android:minSdkVersion="14" 
20.         android:targetSdkVersion="17"/> 
21.  
22.     <uses-feature 
23.         android:name="android.hardware.camera" 
24.         android:required="false"/> 
25.     <uses-feature 
26.         android:name="android.hardware.camera.front" 
27.         android:required="false"/> 
28.     <uses-feature 
29.         android:name="android.hardware.camera.autofocus" 
30.         android:required="false"/> 
31.     <uses-feature 
32.         android:name="android.hardware.camera.flash" 
33.         android:required="false"/> 
34.     <uses-featureandroid:name="android.hardware.screen.landscape"/> 
35.     <uses-feature 
36.         android:name="android.hardware.wifi" 
37.         android:required="false"/> 
38.     <uses-featureandroid:name="android.hardware.touchscreen"/> 
39.  
40.     <supports-screens 
41.         android:anyDensity="true" 
42.         android:largeScreens="true" 
43.         android:normalScreens="true" 
44.         android:smallScreens="true" 
45.         android:xlargeScreens="true"/> 
46.  
47.     <application 
48.         android:allowBackup="true" 
49.         android:icon="@drawable/ic_launcher" 
50.         android:label="@string/app_name" 
51.         android:theme="@style/AppTheme"> 
52.         <activity 
53.             android:name="com.example.scannertest.MainActivity" 
54.             android:label="@string/app_name"> 
55.             <intent-filter> 
56.                 <actionandroid:name="android.intent.action.MAIN"/> 
57.  
58.                 <categoryandroid:name="android.intent.category.LAUNCHER"/> 
59.             </intent-filter> 
60.         </activity> 
61.         <activity 
62.             android:name="com.google.zxing.client.android.CaptureActivity" 
63.             android:clearTaskOnLaunch="true" 
64.             android:configChanges="orientation|keyboardHidden" 
65.             android:screenOrientation="landscape" 
66.             android:stateNotNeeded="true" 
67.             android:theme="@android:style/Theme.NoTitleBar.Fullscreen" 
68.             android:windowSoftInputMode="stateAlwaysHidden"> 
69.             <intent-filter> 
70.                 <actionandroid:name="com.google.zxing.client.android.SCAN"/> 
71.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
72.             </intent-filter> 
73.             <intent-filter> 
74.                 <actionandroid:name="android.intent.action.VIEW"/> 
75.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
76.                 <categoryandroid:name="android.intent.category.BROWSABLE"/> 
77.                 <data 
78.                     android:host="zxing.appspot.com" 
79.                     android:path="/scan" 
80.                     android:scheme="http"/> 
81.             </intent-filter> 
82.             <intent-filter> 
83.                 <actionandroid:name="android.intent.action.VIEW"/> 
84.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
85.                 <categoryandroid:name="android.intent.category.BROWSABLE"/> 
86.                 <data 
87.                     android:host="www.google.com" 
88.                     android:path="/m/products/scan" 
89.                     android:scheme="http"/> 
90.             </intent-filter> 
91.             <intent-filter> 
92.                 <actionandroid:name="android.intent.action.VIEW"/> 
93.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
94.                 <categoryandroid:name="android.intent.category.BROWSABLE"/> 
95.                 <data 
96.                     android:host="www.google.co.uk" 
97.                     android:path="/m/products/scan" 
98.                     android:scheme="http"/> 
99.             </intent-filter> 
100.             <intent-filter> 
101.                 <actionandroid:name="android.intent.action.VIEW"/> 
102.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
103.                 <categoryandroid:name="android.intent.category.BROWSABLE"/> 
104.                 <data 
105.                     android:host="scan" 
106.                     android:path="/" 
107.                     android:scheme="zxing"/> 
108.             </intent-filter> 
109.         </activity> 
110.         <activity 
111.             android:name="com.google.zxing.client.android.PreferencesActivity" 
112.             android:label="@string/preferences_name" 
113.             android:stateNotNeeded="true"> 
114.         </activity> 
115.         <activity 
116.             android:name="com.google.zxing.client.android.encode.EncodeActivity" 
117.             android:stateNotNeeded="true"> 
118.             <intent-filter> 
119.                 <actionandroid:name="com.google.zxing.client.android.ENCODE"/> 
120.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
121.             </intent-filter> 
122.             <intent-filter> 
123.                 <actionandroid:name="android.intent.action.SEND"/> 
124.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
125.                 <dataandroid:mimeType="text/x-vcard"/> 
126.             </intent-filter> 
127.             <intent-filter> 
128.                 <actionandroid:name="android.intent.action.SEND"/> 
129.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
130.                 <dataandroid:mimeType="text/plain"/> 
131.             </intent-filter> 
132.         </activity> 
133.         <activity 
134.             android:name="com.google.zxing.client.android.book.SearchBookContentsActivity" 
135.             android:configChanges="orientation|keyboardHidden" 
136.             android:label="@string/sbc_name" 
137.             android:screenOrientation="landscape" 
138.             android:stateNotNeeded="true"> 
139.             <intent-filter> 
140.                 <actionandroid:name="com.google.zxing.client.android.SEARCH_BOOK_CONTENTS"/> 
141.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
142.             </intent-filter> 
143.         </activity> 
144.         <activity 
145.             android:name="com.google.zxing.client.android.share.ShareActivity" 
146.             android:screenOrientation="user" 
147.             android:stateNotNeeded="true" 
148.             android:theme="@android:style/Theme.Light"> 
149.             <intent-filter> 
150.                 <actionandroid:name="com.google.zxing.client.android.SHARE"/> 
151.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
152.             </intent-filter> 
153.         </activity> 
154.         <activity 
155.             android:name="com.google.zxing.client.android.history.HistoryActivity" 
156.             android:label="@string/history_title" 
157.             android:stateNotNeeded="true"> 
158.             <intent-filter> 
159.                 <actionandroid:name="android.intent.action.VIEW"/> 
160.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
161.             </intent-filter> 
162.         </activity> 
163.         <activity 
164.             android:name="com.google.zxing.client.android.share.BookmarkPickerActivity" 
165.             android:label="@string/bookmark_picker_name" 
166.             android:stateNotNeeded="true"> 
167.             <intent-filter> 
168.                 <actionandroid:name="android.intent.action.PICK"/> 
169.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
170.             </intent-filter> 
171.         </activity> 
172.         <activity 
173.             android:name="com.google.zxing.client.android.share.AppPickerActivity" 
174.             android:configChanges="orientation" 
175.             android:label="@string/app_picker_name" 
176.             android:stateNotNeeded="true"> 
177.             <intent-filter> 
178.                 <actionandroid:name="android.intent.action.PICK"/> 
179.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
180.             </intent-filter> 
181.         </activity> 
182.         <activity 
183.             android:name="com.google.zxing.client.android.HelpActivity" 
184.             android:screenOrientation="user"> 
185.             <intent-filter> 
186.                 <actionandroid:name="android.intent.action.VIEW"/> 
187.                 <categoryandroid:name="android.intent.category.DEFAULT"/> 
188.             </intent-filter> 
189.         </activity> 
190.     </application> 
191.  
192. </manifest> 

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.scannertest"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.VIBRATE" />
    <uses-permission android:name="android.permission.FLASHLIGHT" />
    <uses-permission android:name="android.permission.READ_CONTACTS" />
    <uses-permission android:name="com.android.browser.permission.READ_HISTORY_BOOKMARKS" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="17" />

    <uses-feature
        android:name="android.hardware.camera"
        android:required="false" />
    <uses-feature
        android:name="android.hardware.camera.front"
        android:required="false" />
    <uses-feature
        android:name="android.hardware.camera.autofocus"
        android:required="false" />
    <uses-feature
        android:name="android.hardware.camera.flash"
        android:required="false" />
    <uses-feature android:name="android.hardware.screen.landscape" />
    <uses-feature
        android:name="android.hardware.wifi"
        android:required="false" />
    <uses-feature android:name="android.hardware.touchscreen" />

    <supports-screens
        android:anyDensity="true"
        android:largeScreens="true"
        android:normalScreens="true"
        android:smallScreens="true"
        android:xlargeScreens="true" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.scannertest.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.google.zxing.client.android.CaptureActivity"
            android:clearTaskOnLaunch="true"
            android:configChanges="orientation|keyboardHidden"
            android:screenOrientation="landscape"
            android:stateNotNeeded="true"
            android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
            android:windowSoftInputMode="stateAlwaysHidden" >
            <intent-filter>
                <action android:name="com.google.zxing.client.android.SCAN" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />
                <data
                    android:host="zxing.appspot.com"
                    android:path="/scan"
                    android:scheme="http" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />
                <data
                    android:host="www.google.com"
                    android:path="/m/products/scan"
                    android:scheme="http" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />
                <data
                    android:host="www.google.co.uk"
                    android:path="/m/products/scan"
                    android:scheme="http" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />
                <data
                    android:host="scan"
                    android:path="/"
                    android:scheme="zxing" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.google.zxing.client.android.PreferencesActivity"
            android:label="@string/preferences_name"
            android:stateNotNeeded="true" >
        </activity>
        <activity
            android:name="com.google.zxing.client.android.encode.EncodeActivity"
            android:stateNotNeeded="true" >
            <intent-filter>
                <action android:name="com.google.zxing.client.android.ENCODE" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.SEND" />
                <category android:name="android.intent.category.DEFAULT" />
                <data android:mimeType="text/x-vcard" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.SEND" />
                <category android:name="android.intent.category.DEFAULT" />
                <data android:mimeType="text/plain" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.google.zxing.client.android.book.SearchBookContentsActivity"
            android:configChanges="orientation|keyboardHidden"
            android:label="@string/sbc_name"
            android:screenOrientation="landscape"
            android:stateNotNeeded="true" >
            <intent-filter>
                <action android:name="com.google.zxing.client.android.SEARCH_BOOK_CONTENTS" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.google.zxing.client.android.share.ShareActivity"
            android:screenOrientation="user"
            android:stateNotNeeded="true"
            android:theme="@android:style/Theme.Light" >
            <intent-filter>
                <action android:name="com.google.zxing.client.android.SHARE" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.google.zxing.client.android.history.HistoryActivity"
            android:label="@string/history_title"
            android:stateNotNeeded="true" >
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.google.zxing.client.android.share.BookmarkPickerActivity"
            android:label="@string/bookmark_picker_name"
            android:stateNotNeeded="true" >
            <intent-filter>
                <action android:name="android.intent.action.PICK" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.google.zxing.client.android.share.AppPickerActivity"
            android:configChanges="orientation"
            android:label="@string/app_picker_name"
            android:stateNotNeeded="true" >
            <intent-filter>
                <action android:name="android.intent.action.PICK" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.google.zxing.client.android.HelpActivity"
            android:screenOrientation="user" >
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
    </application>

</manifest>

完成到这一步之后，你会发现项目中还是有很多的错误。不用担心，剩下的错误全部都是由于找不到R文件所造成的。这是因为ZXing项目中所引用的R文件都是com.google.zxing.client.android包下的R，而现在我们拷贝到ScannerTest项目之后，应该引用com.example.scannertest包下的R文件。我们需要将有错误的文件一个个地修改过来，虽然工作量不少，但都是傻瓜式操作，只要大家有耐心，就一定可以完成。

现在ScannerTest项目中应该已经没有任何错误了，然后我们还需要对ZXing的代码进行稍微的定制。

打开CaptureActivity，这个类就是用于扫描二维码的最主要的一个类，其中有一个handleDecode()方法，当二维码扫描完成之后会把结果回调到这个方法中，我们现在不想使用默认的处理方式，于是修改handleDecode()中的代码，如下所示：

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2. public void handleDecode(Result rawResult, Bitmap barcode,float scaleFactor) { 
3.     String result = rawResult.getText(); 
4.     if (!TextUtils.isEmpty(result)) { 
5.         Intent intent = new Intent(); 
6.         intent.putExtra("scan_result", rawResult.getText()); 
7.         setResult(RESULT_OK, intent); 
8.     } else { 
9.         setResult(RESULT_CANCELED); 
10.     } 
11.     finish(); 
12. } 

public void handleDecode(Result rawResult, Bitmap barcode, float scaleFactor) {
  String result = rawResult.getText();
  if (!TextUtils.isEmpty(result)) {
    Intent intent = new Intent();
    intent.putExtra("scan_result", rawResult.getText());
    setResult(RESULT_OK, intent);
  } else {
    setResult(RESULT_CANCELED);
  }
  finish();
}

这里我们将扫描出来的结果借助Intent进行返回。

然后打开或新建activity_main.xml文件做为ScannerTest项目的主布局，在其中添加如下代码：

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2. <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" 
3.     android:layout_width="match_parent" 
4.     android:layout_height="match_parent" 
5.     android:orientation="vertical"> 
6.  
7.     <Button 
8.         android:id="@+id/scan_button" 
9.         android:layout_width="match_parent" 
10.         android:layout_height="wrap_content" 
11.         android:text="扫一扫"/> 
12.  
13.     <TextView 
14.         android:id="@+id/scan_result" 
15.         android:layout_width="wrap_content" 
16.         android:layout_height="wrap_content"/> 
17.  
18. </LinearLayout> 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/scan_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="扫一扫" />

    <TextView
        android:id="@+id/scan_result"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

这个布局文件很简单，一个按钮用于开启二维码扫描功能，一个TextView用于显示扫描结果。

最后打开或新建MainActivity做为ScannerTest项目的主Activity，代码如下所示：

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2. public class MainActivityextends Activity { 
3.  
4.     public staticfinal int SCAN_CODE =1; 
5.  
6.     @Override 
7.     protected void onCreate(Bundle savedInstanceState) { 
8.         super.onCreate(savedInstanceState); 
9.         setContentView(R.layout.activity_main); 
10.         Button button = (Button) findViewById(R.id.scan_button); 
11.         button.setOnClickListener(new OnClickListener() { 
12.             @Override 
13.             public void onClick(View v) { 
14.                 Intent intent = new Intent(MainActivity.this, CaptureActivity.class); 
15.                 startActivityForResult(intent, SCAN_CODE); 
16.             } 
17.         }); 
18.     } 
19.  
20.     @Override 
21.     protected void onActivityResult(int requestCode,int resultCode, Intent data) { 
22.         switch (requestCode) { 
23.         case SCAN_CODE: 
24.             TextView scanResult = (TextView) findViewById(R.id.scan_result); 
25.             if (resultCode == RESULT_OK) { 
26.                 String result = data.getStringExtra("scan_result"); 
27.                 scanResult.setText(result); 
28.             } else if (resultCode == RESULT_CANCELED) { 
29.                 scanResult.setText("扫描出错"); 
30.             } 
31.             break; 
32.         default: 
33.             break; 
34.         } 
35.     } 
36.  
37. } 

public class MainActivity extends Activity {

  public static final int SCAN_CODE = 1;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button button = (Button) findViewById(R.id.scan_button);
    button.setOnClickListener(new OnClickListener() {
      @Override
      public void onClick(View v) {
        Intent intent = new Intent(MainActivity.this, CaptureActivity.class);
        startActivityForResult(intent, SCAN_CODE);
      }
    });
  }

  @Override
  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch (requestCode) {
    case SCAN_CODE:
      TextView scanResult = (TextView) findViewById(R.id.scan_result);
      if (resultCode == RESULT_OK) {
        String result = data.getStringExtra("scan_result");
        scanResult.setText(result);
      } else if (resultCode == RESULT_CANCELED) {
        scanResult.setText("扫描出错");
      }
      break;
    default:
      break;
    }
  }

}

这个类也很简单，点击按钮时，我们通过startActivityForResult()方法启动CaptureActivity，开始执行二维码扫描，扫描的结果将回调到onActivityResult()方法中，然后在这个方法中取出扫描的结果，并展示在TextView上。

这样我们所有的编码工作就已经完成了，可以尝试运行一下了。首先看到程序的主界面如下图所示：

           

点击扫一扫后可以进行二维码扫描，见下图：

扫描完成后会将结果返回到主界面，如下图所示：