PackageManager,PackageInfo，ApplicationInfo ，ResolveInfo 的用法

首先得到PackageManager對象

PackageManager manager = getPackageManager();

ApplicationInfo通過解析AndroidManifest.xml的<application>標籤中得到的，所以它能得到所有的app。

List< ApplicationInfo> appList =manager.getInstalledApplications(PackageManager.GET.UNINSTALLED_PAKAGES);

ResolveInfo通過解析< Intent-filter>標籤得到有:
　　< actionandroid:name=”android.intent.action.MAIN”/>
　　< actionandroid:name=”android.intent.category.LAUNCHER”/>

Intent intent = new Intent(Intent.A CTION_MAIN,null);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
List< ResolveInfo> appList = manager.queryIntentActivities(intent,0);

ResolveInfo獲取圖片、應用名、包名:

                        List<ResolveInfo> resolveList  = Utils.getShareApps(MessageSendActivity.this);
                       
                        for(int i=0;i<resolveList.size();i++) {
                            ResolveInfo resolve = resolveList.get(i);
                            ShareItemInfo shareItem = new ShareItemInfo();
                            //set Icon
                            shareItem.setIcon(resolve.loadIcon(pManager));
                            //set Application Name
                            shareItem.setLabel(resolve.loadLabel(pManager).toString());
                            //set Package Name
                            shareItem.setPackageName(resolve.activityInfo.packageName);
                            //set Class Name                            
                            shareItem.setPackageName(resolve.activityInfo.name);
                        }

通過PackageManager可以獲取手機端已安裝的apk文件的信息:

List<PackageInfo> packageInfoList = packageManager.getInstalledPackages(0);

通過以上方法，可以得到手機中安裝的所有應用程序，既包括了手動安裝的apk包的信息，也包括了系統預裝的應用軟件的信息，要區分這兩類軟件可使用以下方法:

a.從packageInfoList獲取的packageInfo，再通過packageInfo.applicationInfo獲取applicationInfo。

b.判斷(applicationInfo.flags& ApplicationInfo.FLAG_SYSTEM)的值，該值大於0時，表示獲取的應用爲系統預裝的應用，反之則爲手動安裝的應用。

    public static List<PackageInfo> getAllApps(Context context) {
        List<PackageInfo> apps = new ArrayList<PackageInfo>();
        PackageManager pManager = context.getPackageManager();
        //獲取手機內所有應用
        List<PackageInfo> paklist = pManager.getInstalledPackages(0);
        for (int i = 0; i < paklist.size(); i++) {
            PackageInfo pak = (PackageInfo) paklist.get(i);
            //判斷是否爲非系統預裝的應用程序
            if ((pak.applicationInfo.flags & pak.applicationInfo.FLAG_SYSTEM) <= 0) {
                // customs applications
                apps.add(pak);
            }
        }
        return apps;
    }

獲取圖片、應用名、包名:

               PackageManager pManager = MessageSendActivity.this.getPackageManager();
               List<PackageInfo> appList  = Utils.getAllApps(MessageSendActivity.this);    
               for(int i=0;i<appList.size();i++) {
                      PackageInfo pinfo = appList.get(i);
                      ShareItemInfo shareItem = new ShareItemInfo();
                      //set Icon
                      shareItem.setIcon(pManager.getApplicationIcon(pinfo.applicationInfo));
                      //set Application Name
                           shareItem.setLabel(pManager.getApplicationLabel(pinfo.applicationInfo).toString());
                      //set Package Name
                     shareItem.setPackageName(pinfo.applicationInfo.packageName);                          
                }

獲取支持分享的應用的代碼：

    public static List<ResolveInfo> getShareApps(Context context){
        List<ResolveInfo> mApps = new ArrayList<ResolveInfo>(); 
        Intent intent=new Intent(Intent.ACTION_SEND,null); 
        intent.addCategory(Intent.CATEGORY_DEFAULT); 
        intent.setType("text/plain"); 
        PackageManager pManager = context.getPackageManager();
        mApps = pManager.queryIntentActivities(intent,PackageManager.COMPONENT_ENABLED_STATE_DEFAULT);       
        return mApps; 
    }