Android之读取 AndroidManifest.xml 中的数据：版本号、应用名称、自定义K-V数据（meta-data）

AndroidManifest.xml中的定义如下：
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="hpc.cai.test01"
android:versionCode="1"
android:versionName="1.0" >
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<meta-data
android:name="tel"
android:value="cdma-13366350377" >
</meta-data>
<meta-data
android:name="channel"
android:value="eben" />

<activity
android:name="hpc.cai.test.Test1Activity"
android:label="@string/app_name" >
<meta-data
android:name="name"
android:value="自强不息" >
</meta-data>
<meta-data
android:name="city"
android:value="北京" />

<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

package net.duohuo.lequ.activity.other;

import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;

/**
 * Created by ChenZhiNing on 2015/7/30.
 */
public class MetaDataHelper {
 private Activity mActivity;

    public MetaDataHelper(Activity mActivity) {
        this.mActivity = mActivity;
    }

    /**
     * activity MetaData读取
     */
    private void testActivityMetaData() {
        ActivityInfo info;
        try {
            info = mActivity.getPackageManager().getActivityInfo(mActivity.getComponentName(), PackageManager.GET_META_DATA);

            String msg = info.metaData.getString("name");
            System.out.println("name:" + msg);

            msg = info.metaData.getString("city");
            System.out.println("city:" + msg);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * appliction MetaData读取
     */
    private void testApplicationMetaData() {
        ApplicationInfo info;
        try {
            info = mActivity.getPackageManager().getApplicationInfo(mActivity.getPackageName(), PackageManager.GET_META_DATA);

            String msg = info.metaData.getString("tel");
            System.out.println("tel:" + msg);

            msg = info.metaData.getString("channel");
            System.out.println("channel:" + msg);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 测试版本信息
     */
    private void getVersion() {
        PackageInfo pkg;
        try {
            pkg = mActivity.getPackageManager().getPackageInfo(mActivity.getApplication().getPackageName(), 0);
            String appName = pkg.applicationInfo.loadLabel(mActivity.getPackageManager()).toString();
            String versionName = pkg.versionName;
            System.out.println("appName:" + appName);
            System.out.println("versionName:" + versionName);
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
    }
}