一、Android 获取手机中已安装apk文件信息(PackageInfo、ResolveInfo)(应用图片、应用名、包名等)
1、通过PackageManager可获取手机端已安装的apk文件的信息，具体代码如下：
PackageManager packageManager = this.getPackageManager();
List<PackageInfo> packageInfoList = packageManager.getInstalledPackages(0);通过上述方法，可得到手机中安装的所有应用程序，包括手动安装的apk包的信息、、系统预装的应用软件的信息，要区分这两类软件可使用以下方法:
(a) 从packageInfoList获取的packageInfo，再通过packageInfo.applicationInfo获取applicationInfo。
(b) 判断(applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM)的值，该值大于0时，表示获取的应用为系统预装的应用，反之则为手动安装的应用。
(1)获取应用的代码:
public static List<PackageInfo> getAllApps(Context context) {
List<PackageInfo> apps = new ArrayList<PackageInfo>();
PackageManager pManager = context.getPackageManager();
// 获取手机内所有应用
List<PackageInfo> paklist = pManager.getInstalledPackages(0);
for (int i = 0; i < paklist.size(); i++) {
PackageInfo pak = (PackageInfo) paklist.get(i);
// 判断是否为非系统预装的应用程序
if ((pak.applicationInfo.flags & pak.applicationInfo.FLAG_SYSTEM) <= 0) {
apps.add(pak);
}
}
return apps;
}
(2)、获取图片、应用名、包名(ShareItemInfo 类是自己写的，忽视吧):
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);
shareItem = new ShareItemInfo();
shareItem.setIcon(pManager.getApplicationIcon(pinfo.applicationInfo));
shareItem.setLabel(pManager.getApplicationLabel(pinfo.applicationInfo).toString());
shareItem.setPackageName(pinfo.applicationInfo.packageName);
}
(3)获取支持分享的应用的代码：
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;
}由于该方法，返回的并不是PackageInfo 对象。而是ResolveInfo。因此获取图片、应用名、包名的方法不一样，如下：
PackageManager pManager = MessageSendActivity.this.getPackageManager();
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);
}
总结：
通过 PackageInfo 获取具体信息方法：
包名获取方法：packageInfo.packageName
icon获取获取方法：packageManager.getApplicationIcon(applicationInfo)
应用名称获取方法：packageManager.getApplicationLabel(applicationInfo)
使用权限获取方法：packageManager.getPackageInfo(packageName,PackageManager.GET_PERMISSIONS)
.requestedPermissions
通过 ResolveInfo 获取具体信息方法：
包名获取方法：resolve.activityInfo.packageName
icon获取获取方法：resolve.loadIcon(packageManager)
应用名称获取方法：resolve.loadLabel(packageManager).toString()
二、获取手机可用内存和总内存(手机的内存信息主要在/proc/meminfo文件中，其中第一行是总内存，而剩余内存可通过ActivityManager.MemoryInfo得到)：
private String[] getTotalMemory() {
String[] result = {"",""}; //1-total 2-avail
ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
mActivityManager.getMemoryInfo(mi);
long mTotalMem = 0;
long mAvailMem = mi.availMem;
String str1 = "/proc/meminfo";
String str2;
String[] arrayOfString;
try {
FileReader localFileReader = new FileReader(str1);
BufferedReader localBufferedReader = new BufferedReader(localFileReader, 8192);
str2 = localBufferedReader.readLine();
arrayOfString = str2.split("\\s+");
mTotalMem = Integer.valueOf(arrayOfString[1]).intValue() * 1024;
localBufferedReader.close();
} catch (IOException e) {
e.printStackTrace();
}
result[0] = Formatter.formatFileSize(this, mTotalMem);
result[1] = Formatter.formatFileSize(this, mAvailMem);
Log.i(TAG, "meminfo total:" + result[0] + " used:" + result[1]);
return result;
}
三、获取手机CPU信息(和内存信息同理，cpu信息可通过读取/proc/cpuinfo文件来得到，其中第一行为cpu型号，第二行为cpu频率):
private String[] getCpuInfo() {
String str1 = "/proc/cpuinfo";
String str2 = "";
String[] cpuInfo = {"", ""}; //1-cpu型号 //2-cpu频率
String[] arrayOfString;
try {
FileReader fr = new FileReader(str1);
BufferedReader localBufferedReader = new BufferedReader(fr, 8192);
str2 = localBufferedReader.readLine();
arrayOfString = str2.split("\\s+");
for (int i = 2; i < arrayOfString.length; i++) {
cpuInfo[0] = cpuInfo[0] + arrayOfString[i] + " ";
}
str2 = localBufferedReader.readLine();
arrayOfString = str2.split("\\s+");
cpuInfo[1] += arrayOfString[2];
localBufferedReader.close();
} catch (IOException e) {
}
Log.i(TAG, "cpuinfo:" + cpuInfo[0] + " " + cpuInfo[1]);
return cpuInfo;
} private String getMacAddress(){
String result = "";
WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
result = wifiInfo.getMacAddress();
Log.i(TAG, "macAdd:" + result);
return result;
}
五、获取屏幕密度三种方法：
// 获取屏幕密度（方法1）
int screenWidth = getWindowManager().getDefaultDisplay().getWidth(); // 屏幕宽（像素，如：480px）
int screenHeight = getWindowManager().getDefaultDisplay().getHeight(); // 屏幕高（像素，如：800p）
Log.e(TAG + " getDefaultDisplay", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);
// 获取屏幕密度（方法2）
DisplayMetrics dm = new DisplayMetrics();
dm = getResources().getDisplayMetrics();
float density = dm.density; // 屏幕密度（像素比例：0.75/1.0/1.5/2.0）
int densityDPI = dm.densityDpi; // 屏幕密度（每寸像素：120/160/240/320）
float xdpi = dm.xdpi;
float ydpi = dm.ydpi;
Log.e(TAG + " DisplayMetrics", "xdpi=" + xdpi + "; ydpi=" + ydpi);
Log.e(TAG + " DisplayMetrics", "density=" + density + "; densityDPI=" + densityDPI);
screenWidth = dm.widthPixels; // 屏幕宽（像素，如：480px）
screenHeight = dm.heightPixels; // 屏幕高（像素，如：800px）
Log.e(TAG + " DisplayMetrics(111)", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);
// 获取屏幕密度（方法3）
dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
density = dm.density; // 屏幕密度（像素比例：0.75/1.0/1.5/2.0）
densityDPI = dm.densityDpi; // 屏幕密度（每寸像素：120/160/240/320）
xdpi = dm.xdpi;
ydpi = dm.ydpi;
Log.e(TAG + " DisplayMetrics", "xdpi=" + xdpi + "; ydpi=" + ydpi);
Log.e(TAG + " DisplayMetrics", "density=" + density + "; densityDPI=" + densityDPI);
int screenWidthDip = dm.widthPixels; // 屏幕宽（dip，如：320dip）
int screenHeightDip = dm.heightPixels; // 屏幕宽（dip，如：533dip）
Log.e(TAG + " DisplayMetrics(222)", "screenWidthDip=" + screenWidthDip + "; screenHeightDip=" + screenHeightDip);
screenWidth = (int)(dm.widthPixels * density + 0.5f); // 屏幕宽（px，如：480px）
screenHeight = (int)(dm.heightPixels * density + 0.5f); // 屏幕高（px，如：800px）
Log.e(TAG + " DisplayMetrics(222)", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);