Develop Reference

Ban a variable from a list with a "ban" list

How can I ban a variable from a list without removing it from that list by adding the variable to a list of "banned" variable?
I wish to be able to type in a string. That string is compared to the file names in a folder. If there is a match, the file is read. If I type this same string again, the file should not be read again. There for I want to have a list of "banned" string that is checked whilst typing to avoid the file to be read again.
I have tried a few ways but not getting there. Below is an example of my last attempt.
What would be the best way?
public class test
{
string scl= "test3";
List <string> lsf,lso;
void Start ()
{
lsf=//file names
new List<string>();
lso=//files open
new List<string>();
lsf.Add("test0");
lsf.Add("test1");
lsf.Add("test2");
lsf.Add("test3");
lsf.Add("test4");
lso.Add("idhtk49fngo");//random string
}
void Update ()
{
if
(
Input.GetKeyDown("a")
)
{
for
(
int i=0;
i<lsf.Count;
i++
)
{
if(lsf[i]==scl)
{
Debug.Log
(i+" is read");
for
(
int j=0;
j<lso.Count;
j++
)
{
//how can i avoid reading
//lsf[3] here the second time
//"a" is pressed (by having "test3"
//added to a "ban" list (lso) )
if(scl!=lso[j])
{
lso.Add(lsf[i]);
}
}
}
}
}
}

Michael’s answer is the way to go here but it can be improved using the more appropriate collection available to keep track of opened files; if you want uniqueness use a set, not a list:
HashSet<string> openedFiles = new HashSet<string>();
public static bool TryFirstRead(
string path,
out string result)
{
if (openedFiles.Add(path))
{
result = File.ReadAllText(path);
return true;
}
result = null;
return false;
}
Also, I’d avoid throwing vexing exceptions. Give the consumer a friendly way to know if the file was read or not, don’t make them end up having to use exceptions as a flow control mechanism.

I didn't understand although if you want to replace a value from another list.
You can use the list index to create a new list with the values which you removed.
String list1 = {"hi", "hello", "World"};
String list2 = {"bye", "goodbye", "World"};
List1[1] = list2[1];

I would suggest such way:
public static List<string> openedFiles = new List<string>();
public static string ReadFileAndAddToOpenedList(string path)
{
if (openedFiles.Contains(path))
throw new Exception("File already opened");
// Instead of throwing exception you could for example just log this or do something else, like:
// Consolle.WriteLine("File already opened");
else
{
openedFiles.Add(path);
return File.ReadAllText(path);
}
}
The idea is - on every file read, add file to list, so you can check every time you try read file, if it was already read (or opened). If it is, throw exception (or do something else). Else read a file.

You could instead of making it a string list use your own class
public class MyFile
{
public string Name;
public bool isOpen;
public MyFile(string name)
{
Name = name;
isOpen = false;
}
}
List<MyFile> lsf = new List<MyFile>()
{
new MyFile("test0"),
new MyFile("test1"),
new MyFile("test2"),
new MyFile("test3"),
new MyFile("test4")
};
Than when you read the file set isOpen to true
MyFile[someIndex].isOpen = true;
and later you can check this
// E.g. skip in a loop
if(MyFile[someIndex]) continue;
You could than also use Linq in order to get a list of only unread files:
var unreadFiles = lsf.Select(f => f.Name).Where(file => !file.isOpen);

replacing a variable text with other text in c#

I am using c# and sitecore to basically use tokens in certain places ( see: how to create a custom token in sitecore ). I think I have a solution, but am not sure as to why it is not working, even though I am getting no errors.
Item tokenItem = Sitecore.Context.Database.Items["/sitecore/content/Site Content/Tokens"];
if (tokenItem.HasChildren)
{
var sValue = args.FieldValue.ToString();
foreach (Item child in tokenItem.Children)
{
if (child.Template.Name == "Token")
{
string home = child.Fields["Title"].Value;
string hContent = child.Fields["Content"].Value;
if (sValue.Contains(home))
{
home.Replace(home, hContent);
}
}
}
}
home and hContent pull up the correct values of each container, but when the page loads, it still has the "home" value inputted (the ie: ##sales) in the content area instead of the new value, which is stored in hContent. The sValue contains everything (tables, divs, text) and I was trying to single out a value that equals to "home" and replace the "home" value with hContent. What am I missing?

If your code is implemented as a processor for the RenderField pipeline, you need to put the result of your work back into args. Try something like this:
Item tokenItem = Sitecore.Context.Database.Items["/sitecore/content/Site Content/Tokens"];
if (tokenItem.HasChildren)
{
var sValue = args.Result.FirstPart;
foreach (Item child in tokenItem.Children){
if (child.Template.Name == "Token") {
string home = child.Fields["Title"].Value;
string hContent = child.Fields["Content"].Value;
if (sValue.Contains(home)) {
sValue = sValue.Replace(home, hContent);
}
}
}
args.Result.FirstPart = sValue;
}
Note that you need to be sure to patch this processor into the pipeline after the GetFieldValue processor. That processor is responsible for pulling the field value into args.Result.FirstPart.

You code isn't really doing anything. You seem to be replacing the tokens on the token item field itself (child.Fields["Title"] and child.Fields["Content"]), not on the output content stream.
Try the following, you need to set the args to the replaced value, replacing both the FirstPart and LastPart properties: Replace Tokens in Rich Text Fields Using the Sitecore ASP.NET CMS (link to the code in the "untested prototype" link).
I would refactor your code to make it easier:
public void Process(RenderFieldArgs args)
{
args.Result.FirstPart = this.Replace(args.Result.FirstPart);
args.Result.LastPart = this.Replace(args.Result.LastPart);
}
protected string Replace(string input)
{
Item tokenItem = Sitecore.Context.Database.Items["/sitecore/content/Site Content/Tokens"];
if (tokenItem.HasChildren)
{
foreach (Item child in tokenItem.Children)
{
if (child.Template.Name == "Token")
{
string home = child.Fields["Title"].Value;
string hContent = child.Fields["Content"].Value;
if (input.Contains(home))
{
return input.Replace(home, hContent);
}
}
}
}
return input;
}
This is still not optimal, but gets you closer.

Well, Do you know what happens when you performs home.Replace(home, hContent);, it will create a new instance by replacing the content of the come with what is in hContent so what you need to do is, assign this instance to a new variable or to home itself. hence the snippet will be like the following:
if (sValue.Contains(home))
{
home = home.Replace(home, hContent);
}

Have you tried:
home = home.Replace(home,hContent);

Powershell module: Dynamic mandatory hierarchical parameters

So what I really want is somewhat usable tab completion in a PS module.
ValidateSet seems to be the way to go here.
Unfortunately my data is dynamic, so I cannot annotate the parameter with all valid values upfront.
DynamicParameters/IDynamicParameters seems to be the solution for that problem.
Putting these things together (and reducing my failure to a simple test case) we end up with:
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Management.Automation;
using System.Text;
using System.Threading.Tasks;
namespace PSDummy
{
[Cmdlet(VerbsCommon.Get, "BookDetails")]
public class GetBookDetails : Cmdlet, IDynamicParameters
{
IDictionary<string, string[]> m_dummyData = new Dictionary<string, string[]> {
{"Terry Pratchett", new [] {"Small Gods", "Mort", "Eric"}},
{"Douglas Adams", new [] {"Hitchhiker's Guide", "The Meaning of Liff"}}
};
private RuntimeDefinedParameter m_authorParameter;
private RuntimeDefinedParameter m_bookParameter;
protected override void ProcessRecord()
{
// Do stuff here..
}
public object GetDynamicParameters()
{
var parameters = new RuntimeDefinedParameterDictionary();
m_authorParameter = CreateAuthorParameter();
m_bookParameter = CreateBookParameter();
parameters.Add(m_authorParameter.Name, m_authorParameter);
parameters.Add(m_bookParameter.Name, m_bookParameter);
return parameters;
}
private RuntimeDefinedParameter CreateAuthorParameter()
{
var p = new RuntimeDefinedParameter(
"Author",
typeof(string),
new Collection<Attribute>
{
new ParameterAttribute {
ParameterSetName = "BookStuff",
Position = 0,
Mandatory = true
},
new ValidateSetAttribute(m_dummyData.Keys.ToArray()),
new ValidateNotNullOrEmptyAttribute()
});
// Actually this is always mandatory, but sometimes I can fall back to a default
// value. How? p.Value = mydefault?
return p;
}
private RuntimeDefinedParameter CreateBookParameter()
{
// How to define a ValidateSet based on the parameter value for
// author?
var p = new RuntimeDefinedParameter(
"Book",
typeof(string),
new Collection<Attribute>
{
new ParameterAttribute {
ParameterSetName = "BookStuff",
Position = 1,
Mandatory = true
},
new ValidateSetAttribute(new string[1] { string.Empty }/* cannot fill this, because I cannot access the author */),
new ValidateNotNullOrEmptyAttribute()
});
return p;
}
}
}
Unfortunately this tiny snippet causes a lot of issues already. Ordered descending:
I fail to see how I can create a connection between the parameters. If you pick an author, you should only be able to pick a book that matches the author. So far GetDynamicParameters() always seems stateless though: I see no way to access the value of a different/earlier dynamic parameter. Tried keeping it in a field, tried searching MyInvocation - no luck. Is that even possible?
How do you define a default value for mandatory parameter? Doesn't fit the silly example, but let's say you can store your favorite author. From now on I want to default to that author, but having a pointer to an author is still mandatory. Either you gave me a default (and can still specify something else) or you need to be explicit.
Tab completion for strings with spaces seems weird/broken/limited - because it doesn't enclose the value with quotes (like cmd.exe would do, for example, if you type dir C:\Program <tab>). So tab completion actually breaks the invocation (if the issues above would be resolved, Get-BookDetails Ter<tab> would/will expand to Get-BookDetails Terry Pratchett which puts the last name in parameter position 1 aka 'book'.
Shouldn't be so hard, surely someone did something similar already?
Update: After another good day of tinkering and fooling around I don't see a way to make this work. The commandlet is stateless and will be instantiated over and over again. At the point in time when I can define dynamic parameters (GetDynamicParameters) I cannot access their (current) values/see what they'd be bound to - e.g. MyInvocation.BoundParameters is zero. I'll leave the question open, but it seems as if this just isn't supported. All the examples I see add a dynamic parameter based on the value of a static one - and that's not relevant here. Bugger.

I think this works. Unfortunately, it uses reflection to get at some of the cmdlet's private members for your first bullet. I got the idea from Garrett Serack. I'm not sure if I completely understood how to do the default author, so I made it so that the last valid author is stored in a static field so you don't need -Author the next time.
Here's the code:
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Management.Automation;
using System.Text;
using System.Threading.Tasks;
namespace PSDummy
{
internal class DynParamQuotedString {
/*
This works around the PowerShell bug where ValidateSet values aren't quoted when necessary, and
adding the quotes breaks it. Example:
ValidateSet valid values = 'Test string' (The quotes are part of the string)
PowerShell parameter binding would interperet that as [Test string] (no single quotes), which wouldn't match
the valid value (which has the quotes). If you make the parameter a DynParamQuotedString, though,
the parameter binder will coerce [Test string] into an instance of DynParamQuotedString, and the binder will
call ToString() on the object, which will add the quotes back in.
*/
internal static string DefaultQuoteCharacter = "'";
public DynParamQuotedString(string quotedString) : this(quotedString, DefaultQuoteCharacter) {}
public DynParamQuotedString(string quotedString, string quoteCharacter) {
OriginalString = quotedString;
_quoteCharacter = quoteCharacter;
}
public string OriginalString { get; set; }
string _quoteCharacter;
public override string ToString() {
// I'm sure this is missing some other characters that need to be escaped. Feel free to add more:
if (System.Text.RegularExpressions.Regex.IsMatch(OriginalString, #"\s|\(|\)|""|'")) {
return string.Format("{1}{0}{1}", OriginalString.Replace(_quoteCharacter, string.Format("{0}{0}", _quoteCharacter)), _quoteCharacter);
}
else {
return OriginalString;
}
}
public static string[] GetQuotedStrings(IEnumerable<string> values) {
var returnList = new List<string>();
foreach (string currentValue in values) {
returnList.Add((new DynParamQuotedString(currentValue)).ToString());
}
return returnList.ToArray();
}
}
[Cmdlet(VerbsCommon.Get, "BookDetails")]
public class GetBookDetails : PSCmdlet, IDynamicParameters
{
IDictionary<string, string[]> m_dummyData = new Dictionary<string, string[]>(StringComparer.OrdinalIgnoreCase) {
{"Terry Pratchett", new [] {"Small Gods", "Mort", "Eric"}},
{"Douglas Adams", new [] {"Hitchhiker's Guide", "The Meaning of Liff"}},
{"An 'Author' (notice the ')", new [] {"A \"book\"", "Another 'book'","NoSpace(ButCharacterThatShouldBeEscaped)", "NoSpace'Quoted'", "NoSpace\"Quoted\""}} // Test value I added
};
protected override void ProcessRecord()
{
WriteObject(string.Format("Author = {0}", _author));
WriteObject(string.Format("Book = {0}", ((DynParamQuotedString) MyInvocation.BoundParameters["Book"]).OriginalString));
}
// Making this static means it should keep track of the last author used
static string _author;
public object GetDynamicParameters()
{
// Get 'Author' if found, otherwise get first unnamed value
string author = GetUnboundValue("Author", 0) as string;
if (!string.IsNullOrEmpty(author)) {
_author = author.Trim('\'').Replace(
string.Format("{0}{0}", DynParamQuotedString.DefaultQuoteCharacter),
DynParamQuotedString.DefaultQuoteCharacter
);
}
var parameters = new RuntimeDefinedParameterDictionary();
bool isAuthorParamMandatory = true;
if (!string.IsNullOrEmpty(_author) && m_dummyData.ContainsKey(_author)) {
isAuthorParamMandatory = false;
var m_bookParameter = new RuntimeDefinedParameter(
"Book",
typeof(DynParamQuotedString),
new Collection<Attribute>
{
new ParameterAttribute {
ParameterSetName = "BookStuff",
Position = 1,
Mandatory = true
},
new ValidateSetAttribute(DynParamQuotedString.GetQuotedStrings(m_dummyData[_author])),
new ValidateNotNullOrEmptyAttribute()
}
);
parameters.Add(m_bookParameter.Name, m_bookParameter);
}
// Create author parameter. Parameter isn't mandatory if _author
// has a valid author in it
var m_authorParameter = new RuntimeDefinedParameter(
"Author",
typeof(DynParamQuotedString),
new Collection<Attribute>
{
new ParameterAttribute {
ParameterSetName = "BookStuff",
Position = 0,
Mandatory = isAuthorParamMandatory
},
new ValidateSetAttribute(DynParamQuotedString.GetQuotedStrings(m_dummyData.Keys.ToArray())),
new ValidateNotNullOrEmptyAttribute()
}
);
parameters.Add(m_authorParameter.Name, m_authorParameter);
return parameters;
}
/*
TryGetProperty() and GetUnboundValue() are from here: https://gist.github.com/fearthecowboy/1936f841d3a81710ae87
Source created a dictionary for all unbound values; I had issues getting ValidateSet on Author parameter to work
if I used that directly for some reason, but changing it into a function to get a specific parameter seems to work
*/
object TryGetProperty(object instance, string fieldName) {
var bindingFlags = System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.Public;
// any access of a null object returns null.
if (instance == null || string.IsNullOrEmpty(fieldName)) {
return null;
}
var propertyInfo = instance.GetType().GetProperty(fieldName, bindingFlags);
if (propertyInfo != null) {
try {
return propertyInfo.GetValue(instance, null);
}
catch {
}
}
// maybe it's a field
var fieldInfo = instance.GetType().GetField(fieldName, bindingFlags);
if (fieldInfo!= null) {
try {
return fieldInfo.GetValue(instance);
}
catch {
}
}
// no match, return null.
return null;
}
object GetUnboundValue(string paramName) {
return GetUnboundValue(paramName, -1);
}
object GetUnboundValue(string paramName, int unnamedPosition) {
// If paramName isn't found, value at unnamedPosition will be returned instead
var context = TryGetProperty(this, "Context");
var processor = TryGetProperty(context, "CurrentCommandProcessor");
var parameterBinder = TryGetProperty(processor, "CmdletParameterBinderController");
var args = TryGetProperty(parameterBinder, "UnboundArguments") as System.Collections.IEnumerable;
if (args != null) {
var currentParameterName = string.Empty;
object unnamedValue = null;
int i = 0;
foreach (var arg in args) {
var isParameterName = TryGetProperty(arg, "ParameterNameSpecified");
if (isParameterName != null && true.Equals(isParameterName)) {
string parameterName = TryGetProperty(arg, "ParameterName") as string;
currentParameterName = parameterName;
continue;
}
// Treat as a value:
var parameterValue = TryGetProperty(arg, "ArgumentValue");
if (currentParameterName != string.Empty) {
// Found currentParameterName's value. If it matches paramName, return
// it
if (currentParameterName.Equals(paramName, StringComparison.OrdinalIgnoreCase)) {
return parameterValue;
}
}
else if (i++ == unnamedPosition) {
unnamedValue = parameterValue; // Save this for later in case paramName isn't found
}
// Found a value, so currentParameterName needs to be cleared
currentParameterName = string.Empty;
}
if (unnamedValue != null) {
return unnamedValue;
}
}
return null;
}
}
}

Validating Multiple Attributes

I am building an online store for local artists, and one of the requirements is to add an image to be associated with a given product. For the image, there are multiple elements that need to be validated; specifically dimensions, file size, and type.
Currently, I have the following set up to validate the image:
[LocalizedDisplayName(typeof(StoreManagementRes), "Image")]
[ImageSize(typeof(BesLogicSharedRes),"ValidationImageFileSizeMustBeLessThan20kb")]
[ImageDimension(typeof(BesLogicSharedRes), "ValidationImageDimensionMustBeLessThan640x480")]
[ImageType(typeof(BesLogicSharedRes), "ValidationImageTypeMustBeJpgOrPng")]
public int ImageFileId { get; set; }
The file that is uploaded does get validated properly, however, they are not necessarily called in the same order every time the application runs. In the end, if validation fails on more than one attribute, only one error message gets displayed. Again, not necessarily the first failed validation, nor the last. I would like to display all the errors at once so as not to frustrate the user.
If this is relevant, all three image validation classes are sub classed from ValidationAttribute.

One thing to be thankful of is that the model keeps all errors rather than one of them, it's just the HtmlHelper that's displaying the first.
ValidationSummary should in fact display all errors on your model though I suspect you want the equivalent for an individual property.
Unfortunately a couple of the useful methods are private rather than protected so they had to be copy and pasted out of ValidationExtensions.cs. I did this with a slightly cut down version (no use of resource files for error messages, easy enough to do by getting the original version of GetUserErrorMessageOrDefault but you'll also have to check to take the related methods and fields from the class too). I also only did one function call but it's easy enough to impliment the overloads if needed.
public static MvcHtmlString ValidationSummaryForSubModel(this HtmlHelper html, bool excludePropertyErrors, string message, IDictionary<string, object> htmlAttributes)
{
string prefix = html.ViewData.TemplateInfo.HtmlFieldPrefix;
var props = html.ViewData.ModelState.Where(x => x.Key.StartsWith(prefix));
var errorprops = props.Where(x => x.Value.Errors.Any()).SelectMany(x=>x.Value.Errors);
if (html == null) {
throw new ArgumentNullException("html");
}
FormContext formContext = (html.ViewContext.ClientValidationEnabled) ? html.ViewContext.FormContext : null;
if (formContext == null && html.ValidForSubModel())
{
return null;
}
string messageSpan;
if (!String.IsNullOrEmpty(message)) {
TagBuilder spanTag = new TagBuilder("span");
spanTag.SetInnerText(message);
messageSpan = spanTag.ToString(TagRenderMode.Normal) + Environment.NewLine;
}
else {
messageSpan = null;
}
StringBuilder htmlSummary = new StringBuilder();
TagBuilder unorderedList = new TagBuilder("ul");
foreach (ModelError modelError in errorprops) {
string errorText = GetUserErrorMessageOrDefault(html.ViewContext.HttpContext, modelError, null /* modelState */);
if (!String.IsNullOrEmpty(errorText)) {
TagBuilder listItem = new TagBuilder("li");
listItem.SetInnerText(errorText);
htmlSummary.AppendLine(listItem.ToString(TagRenderMode.Normal));
}
}
if (htmlSummary.Length == 0) {
htmlSummary.AppendLine(_hiddenListItem);
}
unorderedList.InnerHtml = htmlSummary.ToString();
TagBuilder divBuilder = new TagBuilder("div");
divBuilder.MergeAttributes(htmlAttributes);
divBuilder.AddCssClass((html.ViewData.ModelState.IsValid) ? HtmlHelper.ValidationSummaryValidCssClassName : HtmlHelper.ValidationSummaryCssClassName);
divBuilder.InnerHtml = messageSpan + unorderedList.ToString(TagRenderMode.Normal);
if (formContext != null) {
// client val summaries need an ID
divBuilder.GenerateId("validationSummary");
formContext.ValidationSummaryId = divBuilder.Attributes["id"];
formContext.ReplaceValidationSummary = !excludePropertyErrors;
}
return MvcHtmlString.Create(divBuilder.ToString(TagRenderMode.Normal));
}
private static string GetUserErrorMessageOrDefault(HttpContextBase httpContext, ModelError error, ModelState modelState)
{
if (!String.IsNullOrEmpty(error.ErrorMessage))
{
return error.ErrorMessage;
}
if (modelState == null)
{
return null;
}
string attemptedValue = (modelState.Value != null) ? modelState.Value.AttemptedValue : null;
//return String.Format(CultureInfo.CurrentCulture, GetInvalidPropertyValueResource(httpContext), attemptedValue);
return "Error";
}

user defined Error collection in Visual C#

I want to write an user defined error collection class which should collect all the Error's. When we validate an entity object if there is no error it should go and save to the Database. if Error there it should display it.
now i have wrote the class it collects the error and displays it successfully but when there is two identical error the class throws an exception.
(i use error-code for the error. the value for the error-code is in resx file from where the display method will take the value and display it. Display works perfectly)
//The code where it collects Error
if (objdepartment.Departmentname == null)
{
ErrorCollection.AddErrors("A1001","Department Name");
}
if (objdepartment.Departmentcode == null)
{
ErrorCollection.AddErrors("A1001","Department code");
}
//In the Errorcollection
public class ErrorCollection
{
static Dictionary<string,List<string>> ErrorCodes;
private ErrorCollection() { }
public static void AddErrors(string eCode,params string[] dataItem)
{
if (ErrorCodes == null)
{
ErrorCodes = new Dictionary<string, List<string>>();
}
List<String> lsDataItem = new List<String>();
foreach (string strD in dataItem)
lsDataItem.Add(strD);
ErrorCodes.Add(eCode, lsDataItem);
}
public static string DisplayErrors()
{
string ErrorMessage;
//string Key;
ErrorMessage = String.Empty;
if (ErrorCodes != null)
{
string Filepath= "D:\\Services\\ErrorCollection\\";
//Read Errors- Language Specsific message from resx file.
ResourceManager rm = ResourceManager.CreateFileBasedResourceManager("ErrorMessages", Filepath, null);
StringBuilder sb = new StringBuilder();
foreach (string error in ErrorCodes.Keys)
{
List<string> list = ErrorCodes[error];
if (error == "A0000")
{
sb.Append("System Exception : " + list[0]);
}
else
{
sb.Append(rm.GetString(error) + "\nBreak\n");
}
for (int counter = 0; counter < list.Count; counter++)
{
sb.Replace("{A}", list[counter]);
}
}
ErrorMessage = sb.ToString();
}
return ErrorMessage;
}
}
now when there is two common error. then the code shows an exception like "datakey already exist" in the line " ErrorCodes.Add(eCode, lsDataItem);" (the italic part where the exception throwed)

Well for one thing, having this statically is a terrible idea. You should create an instance of ErrorCollection to add the errors to IMO, and make the variable an instance variable instead of static.
Then you need to take a different approach within AddErrors, presumably adding all the new items if the key already exists. Something like this:
List<string> currentItems;
if (!ErrorCodes.TryGetValue(eCode, out currentItems))
{
currentItems = new List<string>);
ErrorCodes[eCode] = currentItems;
}
currentItems.AddRange(dataItem);

You are adding "A1001" twice as a key in a dictionary. That simply isn't allowed. However, more urgently - why is that dictionary static? That means that everything, anywhere, shares that error collection.
Suggestions:
make that not static (that is a bad idea - also, it isn't synchronized)
check for existence of the key, and react accordingly:
if(ErrorCodes.ContainsKey(eCode)) ErrorCodes[eCode].AddRange(lsDataItem);
else ErrorCodes.Add(eCode, lsDataItem);
As an aside, you might also consider implementing IDataErrorInfo, which is a built-in standard wrapper for this type of functionality, and will provide support for your error collection to work with a few standard APIs. But don't rush into this until you need it ;p