Android應用開發實用方法小集

/**指定格式返回當前系統時間*/
public static String getDataTime(String format) {
SimpleDateFormat df = new SimpleDateFormat(format);
return df.format(new Date());
}

/** 獲取手機IMEI(移動設備國際身份碼)碼*/
public static String getPhoneIMEI(Context context) {
TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
return tm.getDeviceId();
}

/** 獲取手機系統SDK版本*/
public static int getSDKVersion() {
return android.os.Build.VERSION.SDK_INT;
}

/*** 獲取系統版本*/
public static String getSystemVersion() {
return android.os.Build.VERSION.RELEASE;
}

/**調用系統發送短信*/
public static void sendSMS(Context context, String smsBody) {
Uri smsToUri = Uri.parse("smsto:");
Intent intent = new Intent(Intent.ACTION_SENDTO, smsToUri);
intent.putExtra("sms_body", smsBody);
context.startActivity(intent);
}

/** 判斷網絡是否連接 */
public static boolean checkNet(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo info = cm.getActiveNetworkInfo();
return info != null;//根據連接是否為null來判斷網絡是否連接
}

/**判斷網絡是否為wifi*/
public static boolean isWiFi(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
// wifi的狀態：ConnectivityManager.TYPE_WIFI
// 3G的狀態：ConnectivityManager.TYPE_MOBILE
State state = cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();
return State.CONNECTED == state;
}

/** 判斷當前應用程序是否後台運行 */
public static boolean isBackground(Context context) {
ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
List appProcesses = activityManager.getRunningAppProcesses();
for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {
if (appProcess.processName.equals(context.getPackageName())) {
if (appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_BACKGROUND) {
// 後台運行
return true;
}
else {
// 前台運行
return false;
}
}
}
return false;
}

/** 判斷手機是否處理睡眠 */
public static boolean isSleeping(Context context) {
KeyguardManager kgMgr = (KeyguardManager) context.getSystemService(Context.KEYGUARD_SERVICE);
boolean isSleeping = kgMgr.inKeyguardRestrictedInputMode();
return isSleeping;
}

/**安裝apk */
public static void installApk(Context context, File file) {
Intent intent = new Intent();
intent.setAction("android.intent.action.VIEW");
intent.addCategory("android.intent.category.DEFAULT");
intent.setType("application/vnd.android.package-archive");
intent.setData(Uri.fromFile(file));
intent.setDataAndType(Uri.fromFile(file), "application/vnd.android.package-archive");
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent);
}

/**模擬點擊home鍵，後台運行*/
public static void goHome(Context context) {
Intent mHomeIntent = new Intent(Intent.ACTION_MAIN);
mHomeIntent.addCategory(Intent.CATEGORY_HOME);
mHomeIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
context.startActivity(mHomeIntent);
}

/**獲取應用簽名*/
public static String getSign(Context context, String pkgName) {
try {
PackageInfo pis = context.getPackageManager().getPackageInfo(pkgName, PackageManager.GET_SIGNATURES);
return hexdigest(pis.signatures[0].toByteArray());
}
catch (NameNotFoundException e) {
throw new KJException(SystemTool.class.getName() + "the " + pkgName + "'s application not found");
}
}

/**將簽名字符串轉換成需要的32位簽名*/
private static String hexdigest(byte[] paramArrayOfByte) {
final char[] hexDigits = { 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 97, 98, 99, 100, 101, 102 };
try {
MessageDigest localMessageDigest = MessageDigest.getInstance("MD5");
localMessageDigest.update(paramArrayOfByte);
byte[] arrayOfByte = localMessageDigest.digest();
char[] arrayOfChar = new char[32];
for (int i = 0, j = 0;; i++, j++) {
if (i >= 16) { return new String(arrayOfChar); }
int k = arrayOfByte[i];
arrayOfChar[j] = hexDigits[(0xF & k >>> 4)];
arrayOfChar[++j] = hexDigits[(k & 0xF)];
}
}
catch (Exception e) {
}
return "";
}

/** 獲取設備的可用內存大小*/
public static int getDeviceUsableMemory(Context context) {
ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
MemoryInfo mi = new MemoryInfo();
am.getMemoryInfo(mi);
// 返回當前系統的可用內存(單位：M)
return (int) (mi.availMem / (1024 * 1024));
}


/** 清理後台進程與服務*/
public static int gc(Context context) {
long i = getDeviceUsableMemory(context);
int count = 0; // 清理掉的進程數
ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
// 獲取正在運行的service列表
List serviceList = am.getRunningServices(100);
if (serviceList != null) for (RunningServiceInfo service : serviceList) {
if (service.pid == android.os.Process.myPid()) continue;
try {
android.os.Process.killProcess(service.pid);
count++;
}
catch (Exception e) {
e.getStackTrace();
continue;
}
}