//主要是判斷某個包是否已存在
public static boolean isLinePgAInstalled(Context cxt) {
try {
PackageInfo info = cxt.getPackageManager().getPackageInfo(PACKE_NAME, 0);
if (info != null) {
return true;
}
} catch (NameNotFoundException e) {
e.printStackTrace();
}
return false;
}