c＃在Handler类中从流中读取.csv

Question

I am using Valum's AJAX File Uploader to upload the csv file. The code to initialize it is :

    $(document).ready(function () {          
        var uploader = new qq.FileUploader({
            element: document.getElementById('file-uploader'),
            // path to server-side upload script
            action: 'handlers/PhoneNumberListHandler.ashx',
            buttonTitle: 'Upload Document',
            buttonText: ' Upload',
            allowedExtensions: ['csv'],
            sizeLimit: 1024000, // max size 
        });
    });


<div id="file-uploader"></div>

In c# handler class I have written the following code so far:

    HttpRequest request = context.Request;
    byte[] buffer = new byte[request.ContentLength];
    Stream inputStream;
    string fileName;

    inputStream = request.InputStream;
    fileName = request["qqfile"];

    using (var reader = new StreamReader(inputStream))
    {
        while (!reader.EndOfStream)
        {
            var line = reader.ReadLine();
            var values = line.Split(';'); // gives some abstract characters
        }
    }

My csv file have three columns Phone, Firstname, Lastname where first column is compulsory and rest are optional.

I am now stuck as I am not able to read the .csv file. Can someone please help me and suggest how can I read a csv file content from the stream or is there any other way to do it? I want to extract the csv content and save each line separately in database table.

Update: I made changes in saving the csv file and now the content look like this:

PhoneNumber,FirstName,LastName

11111,Taj,Mahal

22222,Oberai,

33333,,Lake Palace

44444,,

Modified the above code:

    using (var reader = new StreamReader(inputStream))
    {
        List<string> listA = new List<string>();            
        while (!reader.EndOfStream)
        {
            var line = reader.ReadLine();
            var values = line.Split(';');

            listA.Add(values[0]);               
        }
    }

I want to get the individual value of the columns and here I am getting a full line in one string. To get individual value I have to further split it with "," and get the values. I want to know is there a better way to do this?

Answer 1

Converting CSV file to model with reflection. First of all you could create model and set attributes with Name of CSV columns. like this:

     public class UserInfo
    {
        [CSVColumn(ImportName = "FirstName"]
        public string FirstName { get; set; }

        [CSVColumn(ImportName = "LastName"]
        public string LastName { get; set; }

        [CSVColumn(ImportName = "PhoneNumber"]
        public string PhoneNumber { get; set; }
    }

Other steps are reading first line for getting data about columns and based on property attributes of model set data from scv row to each model property:

     List<UserInfo> users = new List<UserInfo>();
     using (var reader = new StreamReader(inputStream))
            {
                //read first line with headers
                var metaDataLine = reader.ReadLine() ?? "";
                //get array with headers
                string[] csvMetada = metaDataLine.Split(',');  

                   while (!reader.EndOfStream)
                    { 
                     // create model based on string data and columns metadata with columns                      
                     UserInfo newModel =   ConvertCSVToEntity(reader.ReadLine() ?? "", csvMetada);
                     users.add(newModel);
                    }
                }

converting method string csv row to model :

        public UserInfo convertCSVToEntity(string line, string[] csvMetada)
        {
            var values = line.Split(',');

            UserInfo newRecord = ConvertorHelper.ConvertCSVToEntity<UserInfo>(values, csvMetada);

            return newRecord;
        }


        public static T ConvertCSVToEntity<T>(string[] csvData, string[] csvMetada) where T : new()
        {
            T returnEntity = new T();
            var properties = returnEntity.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance);

            foreach (var eachProperty in properties)
            {
                var csvAttribute = eachProperty.GetCustomAttribute(typeof(CSVColumn)) as CSVColumn;
                if (csvAttribute != null)
                {
                    int csvIndex = Array.IndexOf(csvMetada, csvAttribute.ImportName);
                    if (csvIndex > -1)
                    {
                        var csvValue = csvData[csvIndex];

                        object setValue = null;
                        try
                        {
                            setValue = string.IsNullOrEmpty(csvValue) && eachProperty.PropertyType != typeof(string) ? Activator.CreateInstance(eachProperty.PropertyType) : Convert.ChangeType(csvValue, eachProperty.PropertyType, ParseCulture);
                        }
                        catch (Exception e)
                        {
                        }
                }
            }

            return returnEntity;
        }

Attributes class

[AttributeUsage(AttributeTargets.Property, AllowMultiple = false)]  



 public class CSVColumn : Attribute
    {
        public string ImportName { set; get; }

        public CSVColumn() { }

        public CSVColumn(string _import)
        {
            this.ImportName = _import;

        }
    }