I'm creating a Store app using C# and XAML. I wanted to show the user the progress of file operations such as file copy. The API I'm using is StorageFile.CopyAsync.
It returns a task which is await-able. So I can tell my app to wait for the operation to finish. But if the file is too large I won't be able to tell how much of it, the app has copied.
Since CopyAsync returns IAsyncOperation<StorageFile> instead of IAsyncOperationWithProgress<StorageFile>, you're out of luck with this API. I don't think there's any built in API for copying that would implement progress reporting (Stream.CopyAsync doesn't implement it either).
You could always implement your own version which copies bytes from one stream to another in chunks and reports progress while doing it. It might be less performant than the built in APIs, though.
Related
I am developing an Android app that gets data from Movesense using the GATT profile from the sample app GATT Sensor Data App here.
I followed the tutorial available here. Building the app and getting the DFU worked fine. I can get IMU, HR and temperature data with no issues.
Now I'd like add a tap detection feature to my app. I understand that I have to subscribe to 'System/States', but first I need to be able to receive the system state data.
I understand that I need a modified DFU for that, but I don't understand what changes I should make in which files of the gatt_sensordata_app before rebuilding and generating the new DFU.
What changes should I make in order to broadcast /System/State data?
(I usually just deal with Android so apologies for the very basic question.)
I tried adding #include "system_states/resources.h" to GATTSensorDataClient.cpp but I don't know how to continue.
The normal data straming in the gatt_sensordata_app uses the sbem-encoding code that the build process generates when building the firmware. However /System/States is not among the paths that the code can serialize. Therefore the only possibility is to implement the States-support to the firmware.
Easiest way is to do as follows:
In your python app call data subscription with "/System/States/3" (3 == DOUBLE_TAP)
Add a special case to the switch in onNotify which matches the localResourceId to the WB_RES::LOCAL::SYSTEM_STATES_STATEID::LID
In that handler, return the data the way you want. Easiest is to copy paste the "default" handler but replace the code between getSbemLength() & writeToSbemBuffer(...) calls with your own serialization code
Full disclosure: I work for the Movesense team
Currently i'm working on a security monitoring app that continuously monitor new processes created.
For that im using wim and event watcher, witch works fine in VB.NET.
But there are 2 features that im missing.
I need to monitor process API calls, and I've been searching the web like mad, and come up empty.
Basically i need to monitor process WaitForSingleObject, LoadLibraryA, CreateProcessW and WriteProcessMemory. And registry access/changes as well.
Im hoping this can be done without a system wide hook, but form what i can find, it cannot be done via WMI.
So the question is, how to, and what can i do with managed code.
I'm gonna focus on the second point as i don't have experience on your first.
For checking if a process is signed i am using the sigcheck.exe from Mark Russinovich, because of the various methods it uses to verify files. Some are catalogsigned, some have the key embedded, there is iirc another weird method. There is no easy way to do it yourself. Had weird false detections with trying self-built methods to cover all possibilities. Hope that info helps
I have a question about WebktGTK.
These days I am making a program which is can analysis web page if has suspicious web content.
When "load-failed" "load-changed" signal is emitted with WEBKIT_LOAD_FINISHED,
The program anlaysis the next page continuously by calling webkit_web_view_load_uri again again.
(http://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebView.html#webkit-web-view-load-uri)
The question want to ask you is memory problem.
The more the program analsysis the webpages, The more WebKitWebProcess is bigger.
webkit_back_forward_list_get_length() return value also increased by analysising web pages. Where shoud I free memory?
Do you know how Can I solve this problem or Could give me any advice where Can I get advice?
Thank you very much :-) Have a nice day ^^
In theory, what you're doing is perfectly fine, and you shouldn't need to change your code at all. In practice, WebKit has a lot of memory leaks, and programatically loading many new URIs in the same web view is eventually going to be problematic, as you've found.
My recommendation is to periodically, every so many page loads, create a new web view that uses a separate web process, and destroy the original web view. (That will also reset the back/forward list to stop it from growing, though I suspect the memory lost to the back/forward list is probably not significant compared to memory leaks when rendering the page.) I filed Bug 151203 - [GTK] Start a new web process when calling webkit_web_view_load functions? to consider having this happen automatically; your issue indicates we may need to bump the priority on that. In the meantime, you'll have to do it manually:
Before doing anything else in your application, set the process model to WEBKIT_PROCESS_MODEL_MULTIPLE_SECONDARY_PROCESSES using webkit_web_context_set_process_model(). (If you are not creating your own web contexts, you'll need to use the default web context webkit_web_context_get_default().)
Periodically destroy your web view with gtk_widget_destroy(), then create a new one using webkit_web_view_new() et. al. and attach it somewhere in your widget hierarchy. (Be sure NOT to use webkit_web_view_new_with_related_view() as that's how you get two web views to use the same web process.)
If you have trouble getting that solution to work, an extreme alternative would be to periodically send SIGTERM to your web process to get a new one. Connect to WebKitWebView::web-process-crashed, and call webkit_web_view_load_uri() from there. That will result in the same web view using a new web process.
I want to create a Metro app for learning and personal consumption purposes to do all sorts of low-level device API work, such as tracking power consumption, enumerating processes and calculating CPU usage per process, etc... Unfortunately, these Desktop APIs are forbidden from Metro applications.
My first attempt to work around this was to create a non-windows store C++ library, which has the WINAPI_FAMILY variable set correctly in order to use functions like QueryIdleProcessorCycleTime() and CallNtPowerInformation(). Unfortunately, it is this latter function call that fails when I pass it the ProcessorInformation token in the first argument, with a STATUS_ACCESS_DENIED return code.
Interestingly, CallNtPowerInformation() works just fine when given SystemBatteryState as the first argument, so I imagine there is some kind of access privilege I am missing when running as a Metro app for getting processor info. I read that Metro apps are run with quite restricted privileges, and so I am looking for a way to increase these privileges to allow my API calls to go through properly. To test that it is the process privileges and not a coding error, I used the C++ library from a console application, and everything worked just fine.
I would really like to not have to create a second, desktop background process that does all the dirty work and communicates the results to the Metro app over a socket. I realize this can work, but I would rather have everything housed in the same process space.
I'm working on something that needs to install files periodically into a folder in /Library.
I understand that in the past I could have used one of the Authenticate methods but those have since been deprecated in 10.7.
What I've understood from my reading so far:
I should create a helper that somehow gets authenticated and have that helper do all of the moving tasks. I've taken a look at some of the sample code, including some involving XPC and one called Elevator but I'm a bit confused.
A lot of it seems to deal with setting up some sort of client / server model but I'm not sure how this would translate into me actually installing my files into the correct directories. Most of the examples are just passing strings.
My question simply: How can I create my folder in /Library programmatically and periodically write files to it while only prompting the user for a password ONCE and never again? I'm really not sure how to approach this and there doesn't seem to be much documentation.
You are correct that there isn't much documentation for this. You'll basically write another app, the helper app, which will get installed with SMJobBless(). Not surprisingly,
the tricky part here is the code signing. The least obvious part for me was that the SMAuthorizedClients and SMPrivilegedExecutables entries in the info plist files of each app are dependent on the identity/certificate that you used to sign the app with. There is also a trick with the compiler/linker to getting the info plist file compiled into the helper tool, which will be a single executable file, rather than a bundle.
Once you get the helper app up and running then you have to devise a way to communicate with it since these are two different processes. XPC is one option, perhaps the easiest. XPC is typically used with server processes, but what you are using here is the communication side of XPC only. Basically it passes dictionaries back and forth between the two apps. Create a standard format for the dictionary. I used #"action", #"source", and #"destination" with 3 different action values, #"filemove", #"filecopy", and #"makedirectory". Those are the 3 things that my helper app can do and I can easily add more if necessary.
The helper app will basically setup the XPC connection and event handler stuff and wait for a connection and commands. The commands will just be a dictionary so you check for the appropriate keys/values and do whatever.
I can provide more details and code if you need more help, but this question is 9 months old so I don't want to waste time giving you details you've already figured out.