I want to set a cache limit for my C# program. My program is creating files periodically and saving them to a folder. I want it so if the folder (C:\SysApp) hits this limit (150000KB) it will automatically start deleting the files starting with the oldest ones deleting only a certain amount at a time (149900KB).
So far I have this code:
private void DeleteOldFilesIfOverFolderLimit(string folderPath,
long folderSizeLimit,
long amountToDelete)
{
var folder = new DirectoryInfo(folderPath);
var files = folder.GetFiles();
var folderSize = files.Sum(fi => fi.Length);
if (folderSize > folderSizeLimit)
{
// Sort the list of files with the oldest first.
Array.Sort(files,
(fi1, fi2) => fi1.CreationTime.CompareTo(fi2.CreationTime));
var amountDeleted = 0L;
foreach (var file in files)
{
amountDeleted += file.Length;
file.Delete();
if (amountDeleted >= amountToDelete)
{
break;
}
}
}
}
I'm just trying to figure out where I need to insert the specific data for my program (given in first paragraph in parenthesis).
I'm using Visual Studio Community 2015.
Click on the project options and select settings:
Enter the default values
and your program can read these values (from the .settings file or the defaults) using the following code
static void Main(string[] args)
{
string folder=Properties.Settings.Default.folder;
long limit=Properties.Settings.Default.sizeLimit;
long delete=Properties.Settings.Default.toDelete;
}
If you change the settings value in the program you need to save the new values before exiting the application. This is done with Properties.Settings.Default.Save();. This command creates a .config file with your values. These are read automatically when the program starts.
The contents are an XML file with the settings values clearly visible.
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<sectionGroup name="userSettings" type="System.Configuration.UserSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="SO_KeepStettings.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowExeDefinition="MachineToLocalUser" requirePermission="false" />
</sectionGroup>
</configSections>
<userSettings>
<SO_KeepStettings.Properties.Settings>
<setting name="folder" serializeAs="String">
<value>C:\SysApp</value>
</setting>
<setting name="sizeLimit" serializeAs="String">
<value>157286400</value>
</setting>
<setting name="toDelete" serializeAs="String">
<value>156237824</value>
</setting>
</SO_KeepStettings.Properties.Settings>
</userSettings>
</configuration>
Deleting files is sketchy, if you accidentally pass in a malformed string or simply the wrong string then you will be losing data, such as accidentally deleting your only copy of your PhD thesis or destroying your operating system. So, I'm just going to show you how to call a method instead of showing you how to use this code you were given:
Starting with a Hello World! example:
public class Hello1
{
public static void Main()
{
System.Console.WriteLine("Hello, World!");
// This is here only to pause the console window so it stays open.
System.Console.ReadLine();
}
}
Now let's implement our own method to print any string to the console:
public class Hello1
{
public static void Main()
{
PrintToConsole("Hello World!");
// This is here only to pause the console window so it stays open.
System.Console.ReadLine();
}
private static void PrintToConsole(string stringToPrintToConsole)
{
System.Console.WriteLine(stringToPrintToConsole);
}
}
Lastly, let's pass in another parameter to control how many times the line is printed:
public class Hello1
{
public static void Main()
{
PrintToConsole("Hello World!", 5);
// This is here only to pause the console window so it stays open.
System.Console.ReadLine();
}
private static void PrintToConsole(string stringToPrintToConsole, long numberOfTimesToPrint)
{
for (int i = 0; i < numberOfTimesToPrint; i++)
{
System.Console.WriteLine(stringToPrintToConsole);
}
}
}
You were given a method but no where are you calling that method. Note how in my program I have to call PrintToConsole() somewhere, and this being a console application the entire program starts and finishes in Main() so that is where I put the code. You could technically take the body of your method and paste it directly into Main, then everywhere you see the usage of the variable folderPath you replace it with the actual string "C:\\SysApp" and likewise with the other 2 parameters and the program would work the same.
Related
I am trying to save user settings in C# and reuse them in the next session.
All over the net, one finds tipps like this:
How to save user settings programatically?
I have a .setting file in my project with the default settings.
When a user changes a setting, I call save, and in %APPDATA% the file appears, with the user settings.
It looks like this:
private void SetSetting(string prop, Object val)
{
try
{
string strval = String.Format("G{0}_{1}", Group_Id, prop);
Properties.Last.Default[strval] = val;
}
catch
{
System.Configuration.SettingsProperty property = new System.Configuration.SettingsProperty(String.Format("G{0}_{1}", Group_Id, prop));
property.PropertyType = Properties.Def.Default[String.Format("G0_{1}", Group_Id, prop)].GetType();
property.DefaultValue = Properties.Def.Default[String.Format("G0_{1}", Group_Id, prop)];
property.PropertyType = val.GetType();
property.Provider = Properties.Last.Default.Providers["LocalFileSettingsProvider"];
property.Attributes.Add(typeof(System.Configuration.UserScopedSettingAttribute), new System.Configuration.UserScopedSettingAttribute());
Properties.Last.Default.Properties.Add(property);
Properties.Last.Default.Reload();
string strval = String.Format("G{0}_{1}", Group_Id, prop);
Properties.Last.Default[strval] = val;
}
Properties.Last.Default.Save();
}
As you can see, I have the settings instance Last as in "settings from last session" and Def as in default.
Basically, a user can add and delete groups at will in the app. Def holds the default configuration for a new group. Last should hold the number of groups in the last user session, as well as the properties of each group. Thus the formatting with the Group_Id and so on.
So, as I said. During runtime, its fine. User settings are properly written to the file in %APPDATA% and everything.
The file is like this:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<sectionGroup name="userSettings" type="System.Configuration.UserSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c5629387e089" >
<section name="Project1.Properties.Last" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c5629387e089" " allowExeDefinition="MachineToLocalUser" requirePermission="false" />
</sectionGroup>
</configSections>
<userSettings>
<Project1.Properties.Last>
<setting name="G1_do_cut" serializeAs="String">
<value>True</value>
</setting>
</Project1.Properties.Last>
</userSettings>
</configuration>
So, the setting for do_cut for Group 1 is saved as G1_do_cut
But as soon as I restart the application, the user setting is ignored.
The code used is:
private Object GetSetting(string prop)
{
try { return Properties.Last.Default[String.Format("G{0}_{1}", Group_Id, prop)]; }
catch { return Properties.Def.Default[String.Format("G0_{1}", Group_Id, prop)]; }
}
and in the try, an exception G1_do_cut is not found in settings is thrown and the catch loads the default.
During a user session, the GetSettings works correctly - if I try to read G1_do_cut after it has been set, no exception is thrown and I get the correct value.
How do I get C# to reuse the settings after restarting the application?
using (StreamWriter sw = new StreamWriter(sName + ".txt", true))
{
iDayNum++; //Adds a day on each time that case 3 is used.
Console.Write("How many minutes have you been exercising? ");
iExcerMinutes = Convert.ToInt32(Console.ReadLine());
Console.WriteLine();
The code inside here works fine but when I reopen the program and ask the program what daynumber I am on it resets, what am I missing?
Hopefully this will help get you started - one technique is as follows.
Right-click your project, select properties/settings and create a user-scope setting.
I just created one called 'RunCount' of type int with value zero in a console application - I set the access modifier to 'public', as it happens.
The following code persists the run count incrementing it as it goes.
class Program
{
static void Main(string[] args)
{
Settings.Default.RunCount += 1;
Settings.Default.Save();
Console.WriteLine(String.Format("This is run number {0} for this user", Settings.Default.RunCount));
Console.WriteLine("Press a key to continue");
Console.ReadKey();
}
}
If you were to run this example, then have a look in c:\users\"yourname"\Appdata\Local\"yourprogramname" you will find a .config file containing :
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<userSettings>
<yourprogramname.Properties.Settings>
<setting name="RunCount" serializeAs="String">
<value>1</value>
</setting>
</yourprogramname.Properties.Settings>
</userSettings>
</configuration>
I added a strongly-typed DataSet object to my project. It's type name is DocRetrieverDataSet.
I also have in my project settings a row for a user-scope DataSet property named DocRetrieverDataSource to which I want to save an instance of DocRetrieverDataSet.
Here is boiled-down code:
using Settings = MyProjectNameSpace.Properties.Settings;
....
private DocRetrieverDataSet myDocRetrieverDataSet;
public myForm()
{
Initialize();
if (Settings.Default.DocRetrieverDataSource == null)
{
Settings.Default.DocRetrieverDataSource = new DocRetrieverDataSet();
Settings.Default.Save();
}
this.myDocRetrieverDataSet = (DocRetrieverDataSet)Settings.Default.DocRetrieverDataSource;
}
The first time I run it, when Settings.Default.DocRetrieverDataSource is null, it works fine! However, when I run it the second time, I get an InvalidCastException at
this.myDocRetrieverDataSet = (DocRetrieverDataSet)Settings.Default.DocRetrieverDataSource;
It says
Unable to cast object of type 'System.Data.DataSet' to type 'DocRetriever.DocRetrieverDataSet'.
The funny thing is that it doesn't have this problem the first time around. What is going on and how can I fix it?
MORE INFO:
Here's the relevant code from Settings.Designer.cs
[global::System.Configuration.UserScopedSettingAttribute()]
[global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
public global::System.Data.DataSet DocRetrieverDataSource {
get {
return ((global::System.Data.DataSet)(this["DocRetrieverDataSource"]));
}
set {
this["DocRetrieverDataSource"] = value;
}
}
And from app.config
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<sectionGroup name="userSettings" type="System.Configuration.UserSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=abcdefghijkl" >
<section name="DocRetriever.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=abcdefghijkl" allowExeDefinition="MachineToLocalUser" requirePermission="false" />
</sectionGroup>
</configSections>
<userSettings>
<DocRetriever.Properties.Settings>
<setting name="SpoolDirectoryPath" serializeAs="String">
<value />
</setting>
<setting name="OutputDirectoryPath" serializeAs="String">
<value />
</setting>
</DocRetriever.Properties.Settings>
</userSettings>
</configuration>
You need to change the casting in your Settings file from DataSet to your DocRetrieverDataSet
[global::System.Configuration.UserScopedSettingAttribute()]
[global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
public global::System.Data.DataSet DocRetrieverDataSource {
get {
return ((global::FullNamespace.DocRetrieverDataSet)(this["DocRetrieverDataSource"]));
}
set {
this["DocRetrieverDataSource"] = value;
}
}
You can also do it via the Settings Designer, just go to your property and browse for you class
Say, for example, I have many methods for calculating the square root of a number.
One developer gives me his own .dll (maths1.dll), another one gives me his too (maths2.dll) and maybe a third one (maths3.dll).
All of them contains the same class, implementing the same interface.
Assembly 1 Maths1.dll
public class Maths : IMaths {
public static string Author = "Author1";
public static SquareRoot(int number) {
// Implementation method 1
}
}
Assembly 2 Maths2.dll
public class Maths : IMaths {
public static string Author = "Author2";
public static SquareRoot(int number) {
// Implementation method 2
}
}
etc. etc.
And I have a console application wich must be aware of all the dlls dynamically at runtime.
Looking for .dll files in code is undesirable.
// DON'T WANT THIS
DirectoryInfo di = new DirectoryInfo("bin");
FileInfo[] fi = di.GetFiles("*.dll");
My idea is to manage them from the app.config file with a custom configuration section.
<configuration>
<configSections>
<section name="MathsLibraries" type="MyMathsLibrariesSectionClass, ApplicationAssembly" />
</configSections>
<MathsLibraries>
<Library author="Author1" type="MathsClass, Maths1Assembly" /><!-- Maths1.dll -->
<Library author="Author2" type="MathsClass, Maths2Assembly" /><!-- Maths2.dll -->
<Library author="Author3" type="MathsClass, Maths3Assembly" /><!-- Maths3.dll -->
</MathsLibraries>
</configuration>
Considering I will manually copy the library file Maths1.dll to my application's bin folder.Then, the only thing I would have to do is, add a line to my app.config file in the MathsLibraries section.
I need an example code for the console application's Main, presenting the user all the dynamically linked .dll's and allowing him to calculate the square root of a number with the chosen library.
// NOT WORKING CODE, JUST IDEA OF WHAT IS NEEDED
public static void Main(string[] args) {
// Show the user the linked libraries
MathsLibraries libs = MathsLibraries.GetSection();
Console.WriteLine("Available libraries:");
foreach (MathLibrary lib in libs.Libraries) {
Console.WriteLine(lib.Author);
}
// Ask for the library to use
Console.Write("Which do you want to use?");
selected_option = Console.Read();
IMaths selected_library;
// since we don't know wich class would be,
// declare a variable using the interface we know they al implement.
// Assign the right class to the variable
if (selected_option == '1') {
selected_library = Assembly1.Maths;
} else if (selected_option == '2') {
selected_library = Assembly2.Maths;
}
// other options...
// Invoke the SquareRoot method of the dynamically loaded class
float sqr_result = selected_library.SquareRoot(100);
Console.WriteLine("Result is {0}", sqr_result);
Console.WriteLine("Press Enter key to exit");
Console.Read();
}
Please, can any one help me in this task of loading assemblies from app.config.
Detailed code would be appreciated.
Thanks!
Assuming they all implement the same interface (actually the same one, declared in the same assembly, not just the same definition in individual namespaces), you could use dependency injection like ms unity, which can be managed in config file, to register all implementations of this interface, create concrete implementations of all at run time, and execute them.
EDIT
Wrote a sample app, I'll post the meat here, and will provide a link to git hub or something when I get it uploaded.
I have an interface, IMasterInterface, and 3 implementations in separate assemblies 'UnityContainer.MasterImplementation', 'Satellite1.Implementation1' and 'Satellite2.Implementation2'. UnityConfiguration is a console app, and I have referenced unity using NuGet. For convenience, I have configured the build paths of all 3 assemblies to the same Build directory for Debug, so the 2 satellite assemblies are available to the console app.
IMasterInterface has a single method GetResult(): string.
Edit web config with the following:
<configuration>
<configSections>
<section name="unity"
type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection,
Microsoft.Practices.Unity.Configuration, Version=3.0.0.0,
Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</configSections>
<unity>
<typeAliases>
<typeAlias alias="IMasterInterface" type="UnityInjection.IMasterInterface, UnityInjection" />
<typeAlias alias="MasterImp" type="UnityInjection.MasterImplementation, UnityInjection" />
<typeAlias alias="SatelliteOneImplementation" type="Satellite1.Implementation1, Satellite1" />
<typeAlias alias="SatelliteTwoImplementation" type="Satellite2.Implementation2, Satellite2" />
</typeAliases>
<containers>
<container name="containerOne">
<types>
<type type="IMasterInterface" mapTo="MasterImp" name="Master" />
<type type="IMasterInterface" mapTo="SatelliteOneImplementation" name="One" />
<type type="IMasterInterface" mapTo="SatelliteTwoImplementation" name="Two" />
</types>
</container>
</containers>
</unity>
</configuration>
Configure the container
//Set up the dependency container
IUnityContainer myContainer = new UnityContainer();
var section = (UnityConfigurationSection)ConfigurationManager.GetSection("unity");
section.Configure(myContainer, "containerOne");
Resolve All implementations
//create all implementations of out interface
var implementations = myContainer.ResolveAll<IMasterInterface>();
//call the method we are interested in for all implementations
foreach (var implementation in implementations)
{
Console.WriteLine(implementation.GetResult());
}
Resolve a specific named implementation
//Get a particular one
var specific = myContainer.Resolve<IMasterInterface>("Master");
Console.WriteLine(specific.GetResult());
You can use reflection to load selected library and create instance of required type.
var assembly = Assembly.LoadFrom("selected_math_library.dll");
var types = assembly.GetTypes();
var mathType = (from type in types
where type.GetInterface("IMath") != null && !type.IsAbstract
select type).ToList();
if (mathType.Count > 0)
{
IMath math = (IMath)Activator.CreateInstance(mathType);
// call methods from math
}
Possible duplicate of C# - Correct Way to Load Assembly, Find Class and Call Run() Method
var asm = Assembly.LoadFile(#"YourMathAssembly.dll");
var type = asm.GetType("Maths");
var sqrRoot = Activator.CreateInstance(Maths) as IMaths;
if (sqrRoot == null)
throw new Exception("broke");
sqrRoot .SquareRoot(100);
Is there any way to load settings from a different file other than the default App.config file at runtime? I'd like to do this after the default config file is loaded.
I use the Settings.Settings GUI in Visual Studio to create my App.config file for me. The config file ends up looking like this:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="SnipetTester.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</sectionGroup>
</configSections>
<applicationSettings>
<SnipetTester.Properties.Settings>
<setting name="SettingSomething" serializeAs="String">
<value>1234</value>
</setting>
</SnipetTester.Properties.Settings>
</applicationSettings>
</configuration>
In code, I'm able to access the settings like this:
Console.WriteLine("Default setting value: " + Properties.Settings.Default.SettingSomething);
The idea is that when the application is run, I should be able to specify a config file at run time and have the application load the config file into the Properties.Settings.Default object instead of using the default app.config file. The formats of the config files would be the same, but the values of the settings would be different.
I know of a way to do this with the ConfigurationManager.OpenExeConfiguration(configFile);. However, in the tests that I've run, it doesn't update the Properties.Settings.Default object to reflect the new values from the config file.
After thinking about this a bit longer, I've been able to come up with a solution that I like a little better. I'm sure it has some pitfalls, but I think it'll work for what I need it to do.
Essentially, the Properties.Settings class is automatically generated by Visual Studio; it generates the code for the class for you. I was able to find where the code was generated and add a few function calls to load a config file on its own. Here's my addition:
internal sealed partial class Settings : global::System.Configuration.ApplicationSettingsBase
{
//Parses a config file and loads its settings
public void Load(string filename)
{
System.Xml.Linq.XElement xml = null;
try
{
string text = System.IO.File.ReadAllText(filename);
xml = System.Xml.Linq.XElement.Parse(text);
}
catch
{
//Pokemon catch statement (gotta catch 'em all)
//If some exception occurs while loading the file,
//assume either the file was unable to be read or
//the config file is not in the right format.
//The xml variable will be null and none of the
//settings will be loaded.
}
if(xml != null)
{
foreach(System.Xml.Linq.XElement currentElement in xml.Elements())
{
switch (currentElement.Name.LocalName)
{
case "userSettings":
case "applicationSettings":
foreach (System.Xml.Linq.XElement settingNamespace in currentElement.Elements())
{
if (settingNamespace.Name.LocalName == "SnipetTester.Properties.Settings")
{
foreach (System.Xml.Linq.XElement setting in settingNamespace.Elements())
{
LoadSetting(setting);
}
}
}
break;
default:
break;
}
}
}
}
//Loads a setting based on it's xml representation in the config file
private void LoadSetting(System.Xml.Linq.XElement setting)
{
string name = null, type = null, value = null;
if (setting.Name.LocalName == "setting")
{
System.Xml.Linq.XAttribute xName = setting.Attribute("name");
if (xName != null)
{
name = xName.Value;
}
System.Xml.Linq.XAttribute xSerialize = setting.Attribute("serializeAs");
if (xSerialize != null)
{
type = xSerialize.Value;
}
System.Xml.Linq.XElement xValue = setting.Element("value");
if (xValue != null)
{
value = xValue.Value;
}
}
if (string.IsNullOrEmpty(name) == false &&
string.IsNullOrEmpty(type) == false &&
string.IsNullOrEmpty(value) == false)
{
switch (name)
{
//One of the pitfalls is that everytime you add a new
//setting to the config file, you will need to add another
//case to the switch statement.
case "SettingSomething":
this[name] = value;
break;
default:
break;
}
}
}
}
The code I added exposes an Properties.Settings.Load(string filename) function. The function accepts a config filename as a parameter. It will parse the file and load up any settings it encounters in the config file. To revert back to the original configuration, simply call Properties.Settings.Reload().
Hope this might help someone else!
Look at using ExeConfigurationFileMap and ConfigurationManager.OpenMappedExeConfiguration.
See Cracking the Mysteries of .Net 2.0 Configuration
The ExeConfigurationFileMap allows you to specifically configure the
exact pathnames to machine, exe, roaming and local configuration
files, all together, or piecemeal, when calling
OpenMappedExeConfiguration(). You are not required to specify all
files, but all files will be identified and merged when the
Configuration object is created. When using
OpenMappedExeConfiguration, it is important to understand that all
levels of configuration up through the level you request will always
be merged. If you specify a custom exe and local configuration file,
but do not specify a machine and roaming file, the default machine and
roaming files will be found and merged with the specified exe and user
files. This can have unexpected consequences if the specified files
have not been kept properly in sync with default files.
It depends on the type of the application:
Web Application & Windows Application - use the configSource xml attribute if you are willing to store the config files in the same folder (or subfolders) as the application
Create a settings provider and also implement IApplicationSettingsProvider. Samples here and here. You might also need to use the IConfigurationManagerInternal interface to replace the default .NET configuration manager. When implementing the provider don't forget to make a difference between user settings and application settings and the roaming profiles.
If you want to get started quickly just decompile the LocalFileSettingsProvider class (the default settings provider) and change it to your needs (you might find some useles code and might need to replicate all of the classes on which it depends).
Good luck
You can include the types so you don't need to manually update the source every time.
`private void LoadSetting(System.Xml.Linq.XElement setting)
{
string name = null, type = null;
string value = null;
if (setting.Name.LocalName == "setting")
{
System.Xml.Linq.XAttribute xName = setting.Attribute("name");
if (xName != null)
{
name = xName.Value;
}
System.Xml.Linq.XAttribute xSerialize = setting.Attribute("serializeAs");
if (xSerialize != null)
{
type = xSerialize.Value;
}
System.Xml.Linq.XElement xValue = setting.Element("value");
if (xValue != null)
{
if (this[name].GetType() == typeof(System.Collections.Specialized.StringCollection))
{
foreach (string s in xValue.Element("ArrayOfString").Elements())
{
if (!((System.Collections.Specialized.StringCollection)this[name]).Contains(s))
((System.Collections.Specialized.StringCollection)this[name]).Add(s);
}
}
else
{
value = xValue.Value;
}
if (this[name].GetType() == typeof(int))
{
this[name] = int.Parse(value);
}
else if (this[name].GetType() == typeof(bool))
{
this[name] = bool.Parse(value);
}
else
{
this[name] = value;
}
}
}`