Saving String values for Tombstoning - c#

I'm currently developing an app for Windows Phone 7.1, and need to save some data for when the user quits the app.
The app is pretty straightforward: the MainPage is the first thing the user sees, in which they select one of four shopping centers. The next page asks them where they have parked their car and stores it as a String variable. The last page loads that String variable and displays back to the user the relevant information, along with a timer that has been ongoing since launching the app.
What I want to save is the user-input data and the timer value when the user leaves the app, so that when launching it again, it automatically shows the last page with the user's info in it.
I've been playing around with the generated Application_Launching, Activated, etc events, but so far can't get something to work. Any help would be greatly appreciated.
Edit: Here's some code that I have so far (hasn't led me anywhere)
void LoadSettings()
{
IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
String mall;
String level;
String letter;
String number;
if (settings.TryGetValue<String>("mall", out mall))
{
_mall = mall;
}
if (settings.TryGetValue<String>("level", out level))
{
_level = level;
}
if (settings.TryGetValue<String>("mall", out letter))
{
_letter = letter;
}
if (settings.TryGetValue<String>("mall", out number))
{
_number = number;
}
}
void SaveSettings()
{
IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
if (_mall != null)
{
settings["mall"] = (_mall as String);
settings["level"] = (_level as String);
settings["letter"] = (_letter as String);
settings["number"] = (_number as String);
}
}
That's in my App.xaml.cs class

You have to look at the events in your app.cs file, but it also depends on what you want when tha application is Activated, Deactived, Closed and launched.
// Code to execute when the application is launching (eg, from Start)
// This code will not execute when the application is reactivated
private void Application_Launching(object sender, LaunchingEventArgs e)
{
LoadSettings();
}
// Code to execute when the application is activated (brought to foreground)
// This code will not execute when the application is first launched
private void Application_Activated(object sender, ActivatedEventArgs e)
{
if (e.IsApplicationInstancePreserved)
{
//The application was dormant and state was automatically preserved
}
else
{
LoadSettings();
}
}
// Code to execute when the application is deactivated (sent to background)
// This code will not execute when the application is closing
private void Application_Deactivated(object sender, DeactivatedEventArgs e)
{
SaveSettings();
}
// Code to execute when the application is closing (eg, user hit Back)
// This code will not execute when the application is deactivated
private void Application_Closing(object sender, ClosingEventArgs e)
{
SaveSettings();
}

Related

how to make sure that function only fires once (RawInputEventArg)

I'm currently working on a method that gives the user the possibility to add a handscanner to a dicitionary in order to scan some barcodes with it. (before i started the scanners were hardcoded in the dictionary). my colleague from which i got this project, implemented the rawinput_dll in order to get all of the necessary data from the barcode scanner. The method to get the data is shown below:
private void OnKeyPressed(object sender, RawInputEventArg e)
{
if (!Scanners.ContainsKey(e.KeyPressEvent.DeviceName))
{
return;
}
else if (Scanners.ContainsKey(e.KeyPressEvent.DeviceName))
{
if (e.KeyPressEvent.KeyPressState == "MAKE")
{
return;
}
if (e.KeyPressEvent.VKeyName != "\n")
{
scanNumber += e.KeyPressEvent.VKeyName;
return;
}
devID = e.KeyPressEvent.DeviceName;
Debug.Print(devID);
Aufrufen(scanNumber);
scanNumber = "";
}
}
Basically there are three classes in this program (FrmMenu, FrmSettings and a Class for the Scanner itself). If you want to add settings for the program you click on a button that opens up a new instance of FrmSettings
private void BtnSettings_Click(object sender, EventArgs e)
{
FrmSettings settings = new FrmSettings();
settings.ShowDialog();
settings.BtnSave_Click(sender, e);
settings.Dispose();
}
In this form there 2 buttons where you can choose if you want to add a scanner that scans even numbers or one that scans odd ones. If you press one of the buttons you need to scan a barcode in order to get the information (VID of Scanner) which is used as key to add the new scanner to the dictionary.
private void OnKeyPressed(object sender, RawInputEventArg e)
{
if (newScanner == true)
{
devIDnew = e.KeyPressEvent.DeviceName;
scannerAnlegen(devIDnew);
}
}
scannerAnlegen is the methode that adds the scanner to the dict.
public void scannerAnlegen(string devIDnew)
{
if(EvenOrOdd == true)
{
Scanner ger = new Scanner("dev3", "even");
FrmMenu.Scanners.Add(devIDnew, ger);
newScanner = false;
}
else
{
Scanner ug = new Scanner("dev4", "odd");
FrmMenu.Scanners.Add(devIDnew, ug);
newScanner = false;
}
}
my problem rn is, that it seems like i cant get out of this OneKeyPressed method of the Settings class. the logic of the OneKeyPressed method of the FrmMenu Class is that it can only proceed if the scanner is in the dictionary. Adding the scanner seems to work because when i debug and try to add one scanner the second time it throws and exception and says something like "element with this key already added". But why does this code doesn't continue then?

Problem Invoking operations in a Windows Form which triggers async API calls

I have a console application which either invokes a class and runs as a console application or triggers a windows form. The windows form inturn sends parameters and invokes the same operation done otherwise.
Invocation point:
static void Main(string[] args)
{
if(AppSettingsHelper.GetValue<bool>("EnableWindowsForm"))
{
System.Console.WriteLine("EnableWindowsForm is set to true - Running Windows form");
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
//Application.Run(new Form1(0));
//First Time
var form = new ReportGeneratorForm();
Application.Run(form);
}
else
{
System.Console.WriteLine("EnableWindowsForm is set to false - Running direct program in console");
PortalMonitoring monitoring = new PortalMonitoring();
monitoring.Process();
}
}
Now In Click of Button the Same Class is triggered
private void button1_Click(object sender, EventArgs e)
{
PortalMonitoring monitoring = new PortalMonitoring();
monitoring.Process(DateTime.Now); //Date as paramater- Default is null
}
If i trigger the console app, it works well.
However if i click the button the code is stuck at point of async web api call -below code
int reportID = GetReportIDAsync().Result;
private static async System.Threading.Tasks.Task<int> GetReportIDAsync()
{
var reportName = "Portal name";
var reportID = await ops.GetReportId(reportName);
LogAndWriteToConsole("Report ID Feched : " + reportID.ToString());
return reportID;
}
Kindly help me here, i think windows form doesnt seem to allow multi threads by defauly. How to fix this ?
You don't show the complete path from monitoring.Process() to GetReportIDAsync() but it needs to be async/await all the way.
The top level should look like this:
private async void button1_Click(object sender, EventArgs e)
{
// probably add a try/catch here
PortalMonitoring monitoring = new PortalMonitoring();
await monitoring.Process(DateTime.Now); //Date as paramater- Default is null
}
Your no-winforms branch shoud then use monitoring.Process().Wait()

How to display data received from serial port in a textbox without the text disappearing in Visual Studio C#?

So, I'm trying to develop a simple application in visual C# which gets data from serial port and displays it in a textbox (to monitor temperature). I'm acquiring and displaying the data successfully, using the DataReceived event to update a global string variable and a timer to update the text field on my text box, as shown:
private void port_DataReceived_1(object sender, SerialDataReceivedEventArgs e)
{
try
{
globalVar.updateTemp = port.ReadLine(); //This is my global string
}
catch (IOException)
{
}
catch (InvalidOperationException)
{
}
catch (TimeoutException)
{
}
}
private void timer1_Tick(object sender, EventArgs e)
{
tempDisplayBox.Text = globalVar.updateTemp; //This is my textbox updating
}
The only issue I have is that the value shown in the textbox keeps flashing, making it hard to read. My timer is set to trigger every 10 ms (which should be fast enough, right?). Is there any way to make it more stable? I realize this may be a newb question, but to be fair I am a newb :) Any help is appreciated! Thanks!
Do you really need it updating every 10ms? What about every 500 ms or if not that then 100ms. 100ms will require your update method run 10 times less and therefore update 10 times less. The flickering you are expiriencing is due to the refresh speed. You could create custom method which will only update the temp only when target Label or textBox value is different than source port. But that will only sort the flickering when temp is steady, when temp will start vary it will bring back the flickering. Good luck ;-)
UPDATE
Hi I tried to reproduce the conditions and could not make my textbox nor Label flash. The way I tested it was by assigning int ntick = 0; and then increment the ++ntick; inside of the timer_tick method. The results didn't make any of the controls flash and were updated even every milisecond at some point. I also tried string.Format to put some load on the method. Is your app responsive?
The trick is to use double buffering. This way the operating system will redraw the Control off-screen, and only show the control when it is fully redrawn.
I have had the same problem, and solved it by extending the TextBox control like this:
public FastLogBox()
{
InitializeComponent();
_logBoxText = new StringBuilder(150000);
timer1.Interval = 20;
timer1.Tick += timer1_Tick;
timer1.Start();
SetStyle(ControlStyles.DoubleBuffer, true);
}
void timer1_Tick(object sender, EventArgs e)
{
if (_timeToClear)
{
_logBoxText.Clear();
_timeToClear = false;
}
if (_logQueue.Count <= 0) return;
while (!_logQueue.IsEmpty)
{
string element;
if (!_logQueue.TryDequeue(out element)) continue;
{
_logBoxText.Insert(0, element + "\r\n");
}
}
if (_logBoxText.Length > 150000)
{
_logBoxText.Remove(150000, _logBoxText.Length - 150001);
}
Text = _logBoxText.ToString();
}
public new void Clear()
{
_timeToClear = true;
while (!_logQueue.IsEmpty)
{
string element;
_logQueue.TryDequeue(out element);
}
}
public void AddToQueue(string message)
{
_logQueue.Enqueue(message);
}
}
I also use a timer and a concurrentQueue to avoid using Invoke to update the control from another thread. I also use a StringBuilder to prepare the string before putting it into the TextBox. StringBuilder is faster when building larger strings.
You can use ReadExisting() to read the whole data at a time.
You need to handle DataReceived Event of SerialPort
serialPort1.ReadExisting();
Sample:
private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
String myData=serialPort1.ReadExisting();
}
Example Code: Here i would like to show you the code to Read Data(RFID Tag Code which is basically of length 12)
String macid = "";
private void DoWork()
{
Invoke(
new SetTextDeleg(machineExe ),
new object[] { macid });
macid = "";
}
private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
string str1;
macid += serialPort1.ReadExisting();
if (macid.Length == 12)
{
macid = macid.Substring(0, 10);
Thread t = new Thread(new ThreadStart(DoWork));
t.Start();
}
}
public void machineExe(string text)
{
TextBox1.Text=text;
}
Thank you so much for the answers! I found a way to work around this issue:
Instead of replacing the contents of my textbox by rewriting the TextBox.Text property - which, as HenningNT implied, refreshes the control and causes the flickering - I'm now using the TextBox.AppendText method. Though, as I want to display only one line of data at a time, I use the textbox in multiline mode and the Environment.NewLine to jump to a new line before appending the text. As for the method of updating, I've gone back to using the timer because with the invoke method was crashing my application when I close the form, for some reason. Also, enabling double buffering didn't do me much good, although I guess I was doing it wrong... It still flickers a bit, but it's much better now :) I know this is not really a perfect solution (much more of a workaround), so I'll keep looking for it. If I find it, I'll be sure to update it here ;) My code:
private void timer1_Tick(object sender, EventArgs e) //Timer to update textbox
{
if (tempDisplayBox.Text != globalVar.updateTemp) //Only update if temperature is different
{
try
{
tempDisplayBox.AppendText(Environment.NewLine);
tempDisplayBox.AppendText(globalVar.updateTemp);
}
catch (NullReferenceException)
{
}
}
}

How to move wpf application into minimize tray at Window Start-up C#?

I have created setup of my application using Windows Installer.
Now I want to Start application at Windows Start-Up and move it system minimize tray as i don't want to display GUI(View) at Windows Start-Up.
I have searched in Google and i found to use Registry key But that is not enough for me as i also want to move to system minimize tray and application run.
My purpose to do it is, user do not feels annoying when application starts every time when he/she starts system.
Can anyone have answer?
Thanks..
In your application, add an event handler for the FrameworkElement.Loaded event. In that handler, add the following code:
WindowState = WindowState.Minimized;
This will minimise the application when it starts.
To start the application when the computer starts, you'll need to add your program into Windows Scheduler and set it to run at startup. You can find out more on the Schedule a task page at MSDN.
You also have to set this property to remove it from the taskbar
ShowInTaskbar= false;
Maybe this answer is late, but I still want to write it down to help those who haven't found solutions yet.
Firstly you need to add a function to minimize your app to tray when it autostarts as system startup.
In your App.xaml file, change the original StartupUri=... to Startup="App_Startup" as below. App_Startup is your function name and can be changed.
<Application x:Class="Yours.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Startup="App_Startup">
In your App.xaml.cs file. Add the function below:
public partial class App : Application
{
private void App_Startup(object sender, StartupEventArgs e)
{
// Process command line args
var isAutoStart = false;
for (int i = 0; i != e.Args.Length; ++i)
{
if (e.Args[i] == "/AutoStart")
{
isAutoStart = true;
}
}
// Create main application window, starting minimized if specified
MainWindow mainWindow = new MainWindow();
if (isAutoStart)
{
mainWindow.WindowState = WindowState.Minimized;
}
mainWindow.OnAutoStart();
}
}
In your MainWindow.xaml.cs, add a function as below:
public void OnAutoStart()
{
if (WindowState == WindowState.Minimized)
{
//Must have this line to prevent the window start locatioon not being in center.
WindowState = WindowState.Normal;
Hide();
//Show your tray icon code below
}
else
{
Show();
}
}
Then you should set you app utostart as system start.
Now if you have a switch to decide whether you app to autostart as system start, you can just add the function below as your switch status changed event function.
private void SwitchAutoStart_OnToggled(object sender, RoutedEventArgs e)
{
const string path = #"SOFTWARE\Microsoft\Windows\CurrentVersion\Run";
var key = Registry.CurrentUser.OpenSubKey(path, true);
if (key == null) return;
if (SwitchAutoStart.IsOn)
{
key.SetValue("Your app name", System.Reflection.Assembly.GetExecutingAssembly().Location + " /AutoStart");
}
else
{
key.DeleteValue("Your app name", false);
}
}
If you want to automatically start the application for all users on Windows startup, just replace the forth line with
RegistryKey key = Registry.LocalMachine.OpenSubKey(path, true);
^_^

Application settings do not allways save

I have a bit of a Heisenbug. I have a list of what was recently searched for sometimes it will save the history some times it does not. When I attach the debugger and step through StartFind() it works every time.
public Form1()
{
oldClinicsBindingSource.DataSource = ContractFlowTool.Properties.Settings.Default.RecentClinics;
}
private void StartFind()
{
(...)
if (oldClinicsBindingSource.Contains(newClinic))
oldClinicsBindingSource.Remove(newClinic);
oldClinicsBindingSource.Insert(0, newClinic);
oldClinicsBindingSource.EndEdit();
while (ContractFlowTool.Properties.Settings.Default.NumberOfClinicsToRemember < oldClinicsBindingSource.Count)
{
oldClinicsBindingSource.RemoveAt(oldClinicsBindingSource.Count - 1);
}
ContractFlowTool.Properties.Settings.Default.Save();
(..)
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{ //Breakpoint on this line
ContractFlowTool.Properties.Settings.Default.Save();
}
//In Settings.Designer.cs
[global::System.Configuration.UserScopedSettingAttribute()]
[global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
public global::System.Collections.ArrayList RecentClinics {
get {
return ((global::System.Collections.ArrayList)(this["RecentClinics"]));
}
set {
this["RecentClinics"] = value;
}
}
If I put a breakpoint on the { before the save inside Form1_FormClosing then hit continue (I don't even step over) it saves correctly. If the breakpoint is not there it does not save.
The program does use background workers in other parts but they not being run in my test case case.
Any help would be greatly appreciated.
Commenting out the Save() inside StartFind() appears to have fixed it.
I am still curious why it was happening. Do binding sources use internal threading?

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