I tried to write to CSV file using CsvHelper in C#.
This is the link to the library http://joshclose.github.io/CsvHelper/
Nothing is sent to the csv file. I tried doing "exportCsv.WriteField("Hello");" but still nothing happened.
List<string> ColumnOne = new List<string>();
List<string> ColumnTwo = new List<string>();
var csvTextWriter = new
StreamWriter(#"C:\Users\Public\Documents\ExportTest.csv");
var exportCsv = new CsvWriter(csvTextWriter);
//creating a list to store workflows then adding name and description to the myWorkflowsList list
if (myWorkflows.WorkFlowCollection.Any())
{
foreach (var Workflow in myWorkflows.WorkFlowCollection)
{
ColumnOne.Add(Workflow.WorkflowName);
ColumnTwo.Add(Workflow.WorkflowDescription);
}
exportCsv.WriteField(ColumnOne);
//exportCsv.WriteField(ColumnTwo);
exportCsv.NextRecord();
exportCsv.Flush();
Console.WriteLine("File is saved:
C:\\Users\\Public\\Documents\\ExportTest.csv");
Console.ReadLine();
}
Your code doesn't add any records. It doesn't have any calls to WriteRecords or WriteRecord. It looks like it's trying to write an entire list of strings into a single field instead.
To write two columns out to a file you can use `WriteRecords, eg :
var data = from flow in myWorkflows.WorkFlowCollection
select new { flow.WorkflowName,flow.WorkflowDescription};
using (var writer = new StreamWriter("test.csv"))
using (var csv = new CsvWriter(writer))
{
csv.WriteRecords(data);
}
This will write a file with field names WorkflowName and WorkflowDescription
You can change how the fields are written by creating a small class that accepts only the fields you want and sets names etc through attributes :
class Flow
{
[NameAttribute("Workflow Name")]
public string WorkflowName { get; set; }
[NameAttribute("Workflow Description")]
public string WorkflowDescription { get; set; }
public Flow(string workflowName, string workflowDescription)
{
WorkflowName = workflowName;
WorkflowDescription = workflowDescription;
}
}
//...
var data = from flow in myWorkflows.WorkFlowCollection
select new Flow(flow.WorkflowName,flow.WorkflowDescription);
using (var writer = new StreamWriter("test.csv"))
using (var csv = new CsvWriter(writer))
{
csv.WriteRecords(data);
}
Related
Currently working with an XML which looks like this. filename introduced below is a List<string>
<Path>
<Entry>
<File>name</File>
<File>folder</File>
<File>directory</File>
<File>drive</File>
<File>filename</File>
</Entry>
</Path>
Trying to get my code to display values of File element
C# code I have tried:
XDocument filefolder = null;
filefolder = XDocument.Load;
string xmlfile = "Path/Entry/File";
foreach(var item in filefolder.GetXPathElements(xmlfile))
{
if(item.Name.ToString() == "File")
{
filename = item.Descendants("Entry").Elements("File").Select(val => val.Value).ToList();
}
}
My code runs well inside the if statement, but I don't get any values for File. I get the count = 0 for File values.
How can I get my code to display all the values of File?
You can create a model from XML using the link https://xmltocsharp.azurewebsites.net/
Then you can deserialize the XML into the model as follows. Once XML is deserialized then LINQ can be used to query.
[XmlRoot(ElementName="Entry")]
public class Entry {
[XmlElement(ElementName="File")]
public List<string> File { get; set; }
}
[XmlRoot(ElementName="Path")]
public class ModelPath {
[XmlElement(ElementName="Entry")]
public Entry Entry { get; set; }
}
Deserialize the xml as:
string inputXmlFilePath = #"D:\Docs\Test\myfile.xml";
ModelPath modelPathObject = null;
XmlSerializer serializer = new XmlSerializer(typeof(ModelPath));
using (FileStream fileStream = new FileStream(MappingFilePath, FileMode.Open))
{
modelPathObject = (ModelPath)serializer.Deserialize(fileStream);
}
Console.WriteLine("Total file lines count:" + modelPathObject.Entry.File.Count);
foreach (var item in modelPathObject.Entry.File)
{
Console.WriteLine("File value is:" + item.ToString());
}
I'm a newbie. I want to get data from the CSV file-the Id and Name fields, but when I run the reading method, I get only 100 lines of an incomprehensible type: "CsvHelper.CsvReaderd__87`1[Program+Product]". I do not know how to get data from CSV, I also cannot understand where the error is.
Although the documentation says that having the same names of properties and CSV headers, you do not need to write additional configurations. However, I get the result specified above. The CSV names match the classes. Link to the documentation:https://joshclose.github.io/CsvHelper/getting-started/
reading method:
{
using (var reader = new StreamReader("C:\\Users\\Saint\\Desktop\\TaskRetail\\file.csv", Encoding.UTF8))
using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture))
{
var records = csv.GetRecords<Product>();
Console.WriteLine($"{records}");
}
}
CSV is created without problems, there are two columns with Id and Name with filled rows, there are 100 rows in total:
method for creating a csv with the Id and Name fields:
using (var writer = new StreamWriter("C:\\Users\\Saint\\Desktop\\TaskRetail\\file.csv", false, Encoding.UTF8))
using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
{
csv.WriteRecords(products);
}
the entire code:
using CsvHelper;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Net;
using System.Text;
using System.Xml;
public class Program
{
public class Product
{
public int Id { get; set; }
public string Name { get; set; }
public Product(int id, string name)
{
Id = id;
Name = name;
}
}
public const string PathToDoc = "C:/Users/Saint/Desktop/TaskRetail/yml.xml";
public static void Main(string[] args)
{
string url = "https://www.googleapis.com/drive/v3/files/1sSR9kWifwjIP5qFWcyxGCxN0-MoEd_oo?alt=media&key=AIzaSyBsW_sj1GCItGBK0vl8hr9zu1I1vTI1Meo";
string savePath = #"C:\Users\Saint\Desktop\TaskRetail\yml.xml";
WebClient client = new WebClient();
client.DownloadFile(url, savePath);
Research();
}
public static void Research()
{
Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
var document = new XmlDocument();
document.Load(PathToDoc);
var xmlDoc = document.SelectNodes("/yml_catalog/shop/offers/offer");
var count = xmlDoc.Count;
var products = new List<Product>();
Console.WriteLine($"Offers count: {count}");
for (var i = 0; i < count; i++)
{
var element = xmlDoc.Item(i);
var id = int.Parse(element.Attributes.GetNamedItem("id").Value);
var name = element.SelectSingleNode("name").InnerText;
var product = new Product(id, name);
//Console.WriteLine($"Id: {id}, name: {name}");
products.Add(product);
using (var writer = new StreamWriter("C:\\Users\\Saint\\Desktop\\TaskRetail\\file.csv", false, Encoding.UTF8))
using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
{
csv.WriteRecords(products);
}
var config = new CsvConfiguration(CultureInfo.InvariantCulture) { Delimiter = ",", PrepareHeaderForMatch = header => header.Header.ToLower() };
using (var reader = new StreamReader("C:\\Users\\Saint\\Desktop\\TaskRetail\\file.csv", Encoding.UTF8))
using (var csv = new CsvReader(reader, config))
{
var records = csv.GetRecords<Product>();
foreach (var record in records)
{
Console.WriteLine($"{record.Id} {record.Name}");
}
}
}
}
}
Because GetRecords() does return an object of type IEnumerable,
you have to iterate over your records to print each one of them:
foreach(var record in records)
{
Console.WriteLine($"{record.Id} {record.Name}");
}
Furthermore you have to access each property you want to print individually.
Another option would be to override the ToString() method in your Product class.
EDIT
The initial problem wasn't the correct printing of the values but the parsing of the file as I learned from this comment:
CsvHelper.HeaderValidationException: 'Header with name 'id'[0] was not found. Header with name 'name'[0] was not found.
To tackle this problem one have to make sure that the delimiter character is set correctly. This can be enforced in the config object of the CsvHelper. Furthermore to avoid casing errors the configuration can be set to ignore the casing of the headers:
var config = new CsvConfiguration(CultureInfo.InvariantCulture)
{
Delimiter = ",", // Enforce ',' as delimiter
PrepareHeaderForMatch = header => header.Header.ToLower() // Ignore casing
};
using (var csv = new CsvReader(reader, config))
{
...
}
I need to manipulate an existing CSV file via following actions:
Read from an existing CSV file -> then Append new row to it.
I have following code which is choking over the 3rd row - as the file is already in use by the code from the 1st row. And I'm not sure how to read it properly otherwise, and then append new row to it.
public bool Save(Customer customer)
{
using (StreamReader input = File.OpenText("DataStoreOut.csv"))
using (CsvReader csvReader = new CsvReader(input))
using (StreamWriter output = File.CreateText("DataStoreOut.csv"))
using (var csvWriter = new CsvWriter(output))
{
IEnumerable<Customer> records = csvReader.GetRecords<Customer>();
List<Customer> customerList = new List<Customer>();
customerList.Add(customer);
csvWriter.WriteHeader<Customer>();
csvWriter.NextRecord();
foreach (var array in customerList)
{
csvWriter.WriteRecord(records.Append(array));
}
}
}
Each of row in the CSV file contains a customer.CustomerId (which is unique, and read-only). How can I read only row which has specific customerId and then update any values there.
If you want to append a record to a file, the best way to do it is read the items, add the new one to the collection, and write everything back.
public static void Append(Customer customer, string file)
{
List<Customer> records = null;
using (var reader = new StreamReader(file))
{
using (var csv = new CsvReader(reader))
{
records = csv.GetRecords<Customer>().ToList();
}
}
records.Add(customer);
using (var writer = new StreamWriter(file))
{
using (var csv = new CsvWriter(writer))
{
csv.WriteRecords(records);
}
}
}
As #Dour High Arch mentioned, to be perfectly safe though you might want to take the extra step of using a temp file in case something goes wrong.
If you want to update instead of append, you'd have to look up the specified record, and update it if it exists.
public static void Update(Customer customer, string file)
{
List<Customer> records = null;
using (var reader = new StreamReader(file))
{
using (var csv = new CsvReader(reader))
{
records = csv.GetRecords<Customer>().ToList();
}
}
var index = records.FindIndex(x => x.ID == customer.ID);
if (index >= 0)
{
records[index] = customer;
using (var writer = new StreamWriter(file))
{
using (var csv = new CsvWriter(writer))
{
csv.WriteRecords(records);
}
}
}
}
Again, writing to a temp file is advisable.
UPDATE
Actually there's a slightly better way to append if you don't want to replace the file. When instantiating a StreamWriter you can do so with append=true. In which case, it will append to the end of the file.
The small caveat is that in case the EOF marker is not at a new line but at the last field of the last record, this will append record to the end of the last field messing up your columns. As a workaround I've added a writer.WriteLine(); before using the CSVHelper class' writer.
public static void Append2(Customer customer, string file)
{
using (var writer = new StreamWriter(file, true))
{
writer.WriteLine();
using (var csv = new CsvWriter(writer))
{
csv.WriteRecord(customer);
}
}
}
In case the file is in a new line, then this will add an empty line though. That can be countered by ignoring empty lines when you read a file.
I am trying to use csv helper libary to parse my csv. But I am having an issue it says that the itemcode does not exist when its there in the file.
// Adding stock item code
Sage.Accounting.Stock.StockItem stockItem = new Sage.Accounting.Stock.StockItem();
string line = null;
public void ImportCsv(string filename)
{
TextReader reader = File.OpenText(filename);
var csv = new CsvReader(reader);
csv.Configuration.HasHeaderRecord = true;
csv.Read();
// Dynamic
// Using anonymous type for the class definition
var anonymousTypeDefinition = new
{
Itemcode = string.Empty,
Barcode = string.Empty
};
var records = csv.GetRecords(anonymousTypeDefinition);
}
This is the csv structure
"Itemcode","Barcode","description"
"P4S100001","303300054486","Test Product"
This is my first time using the csvhelper as showing here at https://joshclose.github.io/CsvHelper/
You are better off creating a strongly typed model to hold the data if one does not already exist
public class Item {
public string Itemcode { get; set; }
public string Barcode { get; set; }
public string description { get; set; }
}
and using GetRecords<T>() to read the records by type
TextReader reader = File.OpenText(filename);
var csv = new CsvReader(reader);
var records = csv.GetRecords<Item>();
Your GetRecords function needs a type specifier like so:
var records = csv.GetRecords<type>();
Also you may want to put csv.Read() in a while loop depending on your need.
Since all your values have quotes you need to specify it in the config. Working with quotes in csvHelper is frustrating. if not all if the values have quotes there are ways to handle that as well but not as nicely as this
var csv = new CsvReader(reader,new CsvHelper.Configuration.Configuration
{
HasHeaderRecord = true,
QuoteAllFields = true
});
var anonymousTypeDefinition = new
{
Itemcode = string.Empty,
Barcode = string.Empty
};
var records = csv.GetRecords(anonymousTypeDefinition);
I'm writing a program to read in CSV files and validate the data. The csv file is comma delimited.
The csv file contains a sales order that is retrieved online so we can't actually edit the CSV file itself. I need to read in the file and split it into the cells. However, the product description will contain further commas which is affecting how I access the data.
My code for pulling the values out is below.
private void csvParse()
{
List<string> products = new List<string>();
List<string> quantities = new List<string>();
List<string> price = new List<string>();
using (var reader = new StreamReader(txt_filePath.Text.ToString()))
{
while (!reader.EndOfStream)
{
var line = reader.ReadLine();
var values = line.Split(',');
products.Add(values[0]);
quantities.Add(values[2]);
values[3] = values[3].Substring(4);
price.Add(values[3]);
}
}
if (validateData(products, quantities, price) != "")
{
MessageBox.Show(validateData(products, quantities, price));
}
}
Is there anyway to ignore the columns in a set cell or can the columns distinguished by another delimiter?
A snippet of a row in my csv file is below.
The raw CSV data is below:
TO12345,"E45 Dermatological Moisturising Lotion, 500 ml",765,GBP 1.75
You can use LinqToCSV from nuGet. ie:
void Main()
{
List<MyData> sample = new List<MyData> {
new MyData {Id=1, Name="Hammer", Description="Everything looks like a nail to a hammer, doesn't it?"},
new MyData {Id=2, Name="C#", Description="A computer language."},
new MyData {Id=3, Name="Go", Description="Yet another language, from Google, cross compiles natively."},
new MyData {Id=3, Name="BlahBlah"},
};
string fileName = #"c:\temp\MyCSV.csv";
File.WriteAllText(fileName,"Id,My Product Name,Ignore1,Ignore2,Description\n");
File.AppendAllLines(fileName, sample.Select(s => $#"{s.Id},""{s.Name}"",""ignore this"",""skip this too"",""{s.Description}"""));
CsvContext cc = new CsvContext();
CsvFileDescription inputFileDescription = new CsvFileDescription
{
SeparatorChar = ',',
FirstLineHasColumnNames = true,
IgnoreUnknownColumns=true
};
IEnumerable<MyData> fromCSV = cc.Read<MyData>(fileName, inputFileDescription);
foreach (var d in fromCSV)
{
Console.WriteLine($#"ID:{d.Id},Name:""{d.Name}"",Description:""{d.Description}""");
}
}
public class MyData
{
[CsvColumn(FieldIndex = 1, Name="Id", CanBeNull = false)]
public int Id { get; set; }
[CsvColumn(FieldIndex = 2, Name="My Product Name",CanBeNull = false, OutputFormat = "C")]
public string Name { get; set; }
[CsvColumn(FieldIndex = 5, Name="Description",CanBeNull = true, OutputFormat = "C")]
public string Description { get; set; }
}
It should work..:)
var csvSplit = new Regex("(?:^|,)(\"(?:[^\"]+|\"\")*\"|[^,]*)", RegexOptions.Compiled);
string[] csvlines = File.ReadAllLines(txt_filePath.Text.ToString());
var query = csvlines.Select(csvline => new
{
data = csvSplit.Matches(csvline)
}).Select(t => t.data);
var row = query.Select(matchCollection =>
(from Match m in matchCollection select (m.Value.Contains(',')) ? m.Value.Replace(",", "") : m.Value)
.ToList()).ToList();
You can also use the Microsoft.VisualBasic.FileIO.TextFieldParser class. More detailed answer here: TextFieldParser