We Keep Coding

How to convert string separated by new line and comma to DataTable in C#

I have a string like this:
"Product,Price,Condition
Cd,13,New
Book,9,Used
"
Which is being passed like this:
"Product,Price,Condition\r\Cd,13,New\r\nBook,9,Used"
How could I convert it to DataTable?
Trying to do it with this helper function:
DataTable dataTable = new DataTable();
bool columnsAdded = false;
foreach (string row in data.Split(new string[] { "\r\n" }, StringSplitOptions.None))
{
DataRow dataRow = dataTable.NewRow();
foreach (string cell in row.Split(','))
{
string[] keyValue = cell.Split('~');
if (!columnsAdded)
{
DataColumn dataColumn = new DataColumn(keyValue[0]);
dataTable.Columns.Add(dataColumn);
}
dataRow[keyValue[0]] = keyValue[1];
}
columnsAdded = true;
dataTable.Rows.Add(dataRow);
}
return dataTable;
However I don't get that "connecting cells with appropriate columns" part - my cells don't have ~ in string[] keyValue = cell.Split('~'); and I obviously get an IndexOutOfRange at DataColumn dataColumn = new DataColumn(keyValue[0]);

Based on your implementation, I have written the code for you, I have not tested it. But you can use the concept.
DataRow dataRow = dataTable.NewRow();
int i = 0;
foreach (string cell in row.Split(','))
{
if (!columnsAdded)
{
DataColumn dataColumn = new DataColumn(cell);
dataTable.Columns.Add(dataColumn);
}
else
{
dataRow[i] = cell;
}
i++;
}
if(columnsAdded)
{
dataTable.Rows.Add(dataRow);
}
columnsAdded = true;

You can do that simply with Linq (and actually there is LinqToCSV on Nuget, maybe you would prefer that):
void Main()
{
string data = #"Product,Price,Condition
Cd,13,New
Book,9,Used
";
var table = ToTable(data);
Form f = new Form();
var dgv = new DataGridView { Dock = DockStyle.Fill, DataSource = table };
f.Controls.Add(dgv);
f.Show();
}
private DataTable ToTable(string CSV)
{
DataTable dataTable = new DataTable();
var lines = CSV.Split(new char[] { '\n' }, StringSplitOptions.RemoveEmptyEntries);
foreach (var colname in lines[0].Split(','))
{
dataTable.Columns.Add(new DataColumn(colname));
}
foreach (var row in lines.Where((r, i) => i > 0))
{
dataTable.Rows.Add(row.Split(','));
}
return dataTable;
}

You can split given string into flattened string array in one call. Then you can iterate through the array and populate list of objects.
That part is optional, since you can immediately populate DataTable but I think it's way easier (more maintainable) to work with strongly-typed objects when dealing with DataTable.
string input = "Product,Price,Condition\r\nCd,13,New\r\nBook,9,Used";
string[] deconstructedInput = input.Split(new string[] { "\r\n", "," }, StringSplitOptions.None);
List<Product> products = new List<Product>();
for (int i = 3; i < deconstructedInput.Length; i += 3)
{
products.Add(new Product
{
Name = deconstructedInput[i],
Price = Decimal.Parse(deconstructedInput[i + 1]),
Condition = deconstructedInput[i + 2]
});
}
public class Product
{
public string Name { get; set; }
public decimal Price { get; set; }
public string Condition { get; set; }
}
So, products collection holds 2 objects which you can easily iterate over and populate your DataTable.
Note: This requires further checks to avoid possible runtime exceptions, also it is not dynamic. That means, if you have differently structured input it won't work.
DataTable dataTable = new DataTable();
dataTable.Columns.Add(new DataColumn(nameof(Product.Name)));
dataTable.Columns.Add(new DataColumn(nameof(Product.Price)));
dataTable.Columns.Add(new DataColumn(nameof(Product.Condition)));
foreach (var product in products)
{
var row = dataTable.NewRow();
row[nameof(Product.Name)] = product.Name;
row[nameof(Product.Price)] = product.Price;
row[nameof(Product.Condition)] = product.Condition;
dataTable.Rows.Add(row);
}

Arraylist multiple dimensions C# 2.0

I am trying to create a multi dimension array
What I have so far is...
ArrayList iEFiles = (ArrayList)Session["Files"];
iEFiles.Add(Server.MapPath(FileName));
FileName = "Testing123"
FileName = "AnotherTest"
What I want it to do is have it come out like this...
FileName = ("Testing123", "Waterproof")
FileName = ("AnotherTest", "Non-Waterproof")
Like Array[,]
Any ideas?
To display the records...
BindGridview(iEFiles);
private void BindGridview(ArrayList list)
{
DataTable dt = new DataTable();
dt.Columns.Add("FileName");
dt.Columns.Add("id");
dt.Columns.Add("snFile");
int c = list.Count;
for (int i = 0; i < c; i++)
{
dt.Rows.Add();
dt.Rows[i]["FileName"] = list[i].ToString().ToUpper();
dt.Rows[i]["id"] = i;
dt.Rows[i]["snFile"] = list[i].ToString();
}
GridView1.DataSource = dt;
GridView1.DataBind();
}

You could use the Hashtable / Dictionary to store the key value pair. If you do not want that you can make a class having two attributes FileName and Value and store object of that class in ArrayList or preferably generic List<T>.
class FileInformation
{
public FileInformation(string fileName, string value)
{
FileName = fileName;
Value = value;
}
public string FileName;
public string Value;
}
List<FileInformation> lst = new List<FileInformation>();
lst.Add(new FileInformation("fileName", "somevalue"));

An ArrayList is a bit of a .net 1.x throwback before we had generics.
You could use Dictionary<string,string> to store these values but the first item is a key and has to be unique. If you just want to store a list of 2 values you could use something like List<KeyValuePair<string,string>> or List<string[]>.

Bind list to gridview C#

I'm trying to bind list to gridview. Situation is like this: I take data from .txt file, later I put it inside first list List<Mycolumns>. I have data in list (with 3 separated columns) that I created. I am taking data from one of the columns called System_Description. Now I would like to show this data in gridview, but only thing that I get is length of each row. How should I fix it? Here is my code.
private void button7_Click(object sender, EventArgs e)
{
List<MyColumns> list = new List<MyColumns>();
OpenFileDialog openFile1 = new OpenFileDialog();
openFile1.Multiselect = true;
if (openFile1.ShowDialog() != DialogResult.Cancel)
{
foreach (string filename in openFile1.FileNames)
{
using (StreamReader sr = new StreamReader(filename))
{
string line;
while ((line = sr.ReadLine()) != null)
{
string[] _columns = line.Split(",".ToCharArray());
MyColumns mc = new MyColumns();
mc.Time = _columns[0];
mc.System_Description = _columns[1];
mc.User_Description = _columns[2];
list.Add(mc);
}
}
}
DataTable ListAsDataTable = BuildDataTable<MyColumns>(list);
DataView ListAsDataView = ListAsDataTable.DefaultView;
this.dataGridView1.DataSource = view = ListAsDataView;
this.dataGridView1.AllowUserToAddRows = false;
dataGridView1.ClearSelection();
}
List<string> description = list.Select(x => x.System_Description).ToList<string>();
this.dataGridView2.DataSource = description;
}
class MyColumns
{
public string Time { get; set; }
public string System_Description { get; set; }
public string User_Description { get; set; }
}
EDIT:
I've read that DataBind() works for Web form, my app is desktop app. What should I do now?

I managed to solve this problem. I did it this way, maybe it will help someone. You can use DataTable and then bind DT to gridview.
DataTable dt = new DataTable();
dt.Columns.Add("values");
foreach(string items in description)
{
DataRow row = dt.NewRow();
dt.Rows.Add(items);
}
this.dataGridView2.DataSource = dt;

this.dataGridView1.DataSource = new BindingSource(list);

You are only selecting the System_Description field using the following statement:
List<string> description = list.Select(x => x.System_Description).ToList<string>();
Then you are binding this list to the gridview:
this.dataGridView2.DataSource = description;
If you want to bind the whole data to the gridview; just bind the list as a datasource.
this.dataGridView2.DataSource = list;
this.dataGridView2.DataBind();

Use this
this.dataGridView1.DataSource = description;
and add Bound field in gridview on aspx.
<asp:BoundField DataField="System_Description" HeaderText="System_Description"></asp:BoundField>

how to set SelectedIndex in DataGridViewComboBoxColumn?

i am using a datagridview in that i am using a datagridviewcomboboxcolumn, comboboxcolumn is displaying text but the problem is i want to select the first item of comboboxcolumn by default how can i do this
DataGridViewComboBoxColumn dgvcb = (DataGridViewComboBoxColumn)grvPackingList.Columns["PackingUnits"];
Globals.G_ProductUtility G_Utility = new Globals.G_ProductUtility();
G_Utility.addUnittoComboDGV(dgvcb);
DataSet _ds = iRawMaterialsRequest.SelectBMR(bmr_ID, branch_ID, "PACKING");
grvPackingList.DataSource = _ds.Tables[0];
int i = 0;
foreach (DataRow dgvr in _ds.Tables[0].Rows)
{
grvPackingList.Rows[i].Cells["Units"].Value = dgvr["Units"].ToString();
i++;
}

The values available in the combobox can be accessed via items property
row.Cells[col.Name].Value = (row.Cells[col.Name] as DataGridViewComboBoxCell).Items[0];

the best way to set the value of a datagridViewComboBoxCell is:
DataTable dt = new DataTable();
dt.Columns.Add("Item");
dt.Columns.Add("Value");
dt.Rows.Add("Item1", "0");
dt.Rows.Add("Item1", "1");
dt.Rows.Add("Item1", "2");
dt.Rows.Add("Item1", "3");
DataGridViewComboBoxColumn cmb = new DataGridViewComboBoxColumn();
cmb.DefaultCellStyle.Font = new Font("Tahoma", 8, FontStyle.Bold);
cmb.DefaultCellStyle.ForeColor = Color.BlueViolet;
cmb.FlatStyle = FlatStyle.Flat;
cmb.Name = "ComboColumnSample";
cmb.HeaderText = "ComboColumnSample";
cmb.DisplayMember = "Item";
cmb.ValueMember = "Value";
DatagridView dvg=new DataGridView();
dvg.Columns.Add(cmb);
cmb.DataSource = dt;
for (int i = 0; i < dvg.Rows.Count; i++)
{
dvg.Rows[i].Cells["ComboColumnSample"].Value = (cmb.Items[0] as
DataRowView).Row[1].ToString();
}
It worked with me very well

If I had known about doing it in this event, it would have saved me days of digging and
trial and errors trying to get it to set to the correct index inside the CellEnter event.
Setting the index of the DataGridViewComboBox is the solution I have been looking for.....THANKS!!!
In reviewing all the issues other coders have been experiencing with trying to set
the index inside of a DataGridViewComboBoxCell and also after looking over your code,
all that anyone really needs is:
1. Establish the event method to be used for the "EditingControlShowing" event.
2. Define the method whereby it will:
a. Cast the event control to a ComboBox.
b. set the "SelectedIndex" to the value you want.
In this example I simply set it to "0", but you'd probably want to apply so real life logic here.
Here's the code I used:
private void InitEvents()
{
dgv4.EditingControlShowing += new DataGridViewEditingControlShowingEventHandler( dgv4EditingControlShowing );
}
private void dgv4EditingControlShowing( object sender, DataGridViewEditingControlShowingEventArgs e )
{
ComboBox ocmb = e.Control as ComboBox;
if ( ocmb != null )
{
ocmb.SelectedIndex = 0;
}
}

If DataGridViewComboBoxCell already exist:
DataTable dt = new DataTable();
dt.Columns.Add("Item");
dt.Columns.Add("Value");
dt.Rows.Add("Item 1", "0");
dt.Rows.Add("Item 2", "1");
dt.Rows.Add("Item 3", "2");
dt.Rows.Add("Item 4", "3");
for (int i = 0; i < dvg.Rows.Count; i++)
{
DataGridViewComboBoxCell comboCell = (DataGridViewComboBoxCell)dvg.Rows[i].Cells[1];
comboCell.DisplayMember = "Item";
comboCell.ValueMember = "Value";
comboCell.DataSource = dt;
};

I've had some real trouble with ComboBoxes in DataGridViews and did not find an elegant way to select the first value. However, here is what I ended up with:
public static void InitDGVComboBoxColumn<T>(DataGridViewComboBoxCell cbx, List<T> dataSource, String displayMember, String valueMember)
{
cbx.DisplayMember = displayMember;
cbx.ValueMember = valueMember;
cbx.DataSource = dataSource;
if (cbx.Value == null)
{
if(dataSource.Count > 0)
{
T m = (T)cbx.Items[0];
FieldInfo fi = m.GetType().GetField(valueMember, BindingFlags.Instance | BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Public);
cbx.Value = fi.GetValue(m);
}
}
}
It basically sets the .Display and .ValueMember properties of the DataGridViewComboBoxCell and uses a List as DataSource. It then takes the first item, and uses reflection to get the value of the member that was used as ValueMember and sets the selected value via .Value
Use it like this:
public class Customer
{
private String name;
public String Name
{
get {return this.name; }
set {this.name = value; }
}
private int id;
public int Id
{
get {return this.id; }
set {this.id = value; }
}
}
public class CustomerCbx
{
private String display;
public String Display
{
get {return this.display; }
set {this.display = value; }
}
private Customer value;
public Customer Value
{
get {return this.value; }
set {this.value = value; }
}
}
public class Form{
private void Form_OnLoad(object sender, EventArgs e)
{
//init first row in the dgv
if (this.dgv.RowCount > 0)
{
DataGridViewRow row = this.dgv.Rows[0];
DataGridViewComboBoxCell cbx = (DataGridViewComboBoxCell)row.Cells[0];
Customer c1 = new Customer(){ Name = "Max Muster", ID=1 };
Customer c2 = new Customer(){ Name = "Peter Parker", ID=2 };
List<CustomerCbx> custList = new List<CustomerCbx>()
{
new CustomerCbx{ Display = c1.Name, Value = c1},
new CustomerCbx{ Display = c2.Name, Value = c2},
}
InitDGVComboBoxColumn<CustomerCbx>(cbx, custList, "display", "value");
}
}
}
}
It seems pretty hacky to me, but I couldn't find any better way so far (that also works with complex objects other than just Strings). Hope that will save the search for some others ;)

You need to set the Items for the new cell. This must be auto done by the column when creating a new row from the UI.
var cell = new DataGridViewComboBoxCell() { Value = "SomeText" };
cell.Items.AddRange(new String[]{"SomeText", "Abcd", "123"});

something different worked for me what i did is to simply set the value of dtataGridComboBox when ever new record is added bu user with 'userAddedRow' event. For the first row I used the code in constructor.
public partial class pt_drug : PatientDatabase1_3._5.basic_templet
{
public pt_drug()
{
InitializeComponent();
dataGridView_drugsDM.Rows[0].Cells[0].Value = "Tablet";
}
private void dataGridView_drugsDM_UserAddedRow(object sender, DataGridViewRowEventArgs e)
{
dataGridView_drugsDM.Rows[dataGridView_drugsDM.RowCount - 1].Cells[0].Value = "Tablet";
}
}

Here the solution I have found : select the cell you are interested in so you can cast it to a combobox.
this.Invoke((MethodInvoker)delegate
{
this.dataGridView1.CurrentCell = dataGridView1.Rows[yourRowindex].Cells[yourColumnIndex];
this.dataGridView1.BeginEdit(true);
ComboBox comboBox = (ComboBox)this.dataGridView1.EditingControl;
comboBox.SelectedIndex += 1;
});

How to bind list to dataGridView?

I seem to be running around in circles and have been doing so in the last hours.
I want to populate a datagridview from an array of strings. I've read its not possible directly, and that I need to create a custom type that holds the string as a public property. So I made a class:
public class FileName
{
private string _value;
public FileName(string pValue)
{
_value = pValue;
}
public string Value
{
get
{
return _value;
}
set { _value = value; }
}
}
this is the container class, and it simply has a property with the value of the string. All I want now is that string to appear in the datagridview, when I bind its datasource to a List.
Also I have this method, BindGrid() which I want to fill the datagridview with. Here it is:
private void BindGrid()
{
gvFilesOnServer.AutoGenerateColumns = false;
//create the column programatically
DataGridViewTextBoxColumn colFileName = new DataGridViewTextBoxColumn();
DataGridViewCell cell = new DataGridViewTextBoxCell();
colFileName.CellTemplate = cell; colFileName.Name = "Value";
colFileName.HeaderText = "File Name";
colFileName.ValueType = typeof(FileName);
//add the column to the datagridview
gvFilesOnServer.Columns.Add(colFileName);
//fill the string array
string[] filelist = GetFileListOnWebServer();
//try making a List<FileName> from that array
List<FileName> filenamesList = new List<FileName>(filelist.Length);
for (int i = 0; i < filelist.Length; i++)
{
filenamesList.Add(new FileName(filelist[i].ToString()));
}
//try making a bindingsource
BindingSource bs = new BindingSource();
bs.DataSource = typeof(FileName);
foreach (FileName fn in filenamesList)
{
bs.Add(fn);
}
gvFilesOnServer.DataSource = bs;
}
Finally, the problem: the string array fills ok, the list is created ok, but I get an empty column in the datagridview. I also tried datasource= list<> directly, instead of = bindingsource, still nothing.
I would really appreciate an advice, this has been driving me crazy.

Use a BindingList and set the DataPropertyName-Property of the column.
Try the following:
...
private void BindGrid()
{
gvFilesOnServer.AutoGenerateColumns = false;
//create the column programatically
DataGridViewCell cell = new DataGridViewTextBoxCell();
DataGridViewTextBoxColumn colFileName = new DataGridViewTextBoxColumn()
{
CellTemplate = cell,
Name = "Value",
HeaderText = "File Name",
DataPropertyName = "Value" // Tell the column which property of FileName it should use
};
gvFilesOnServer.Columns.Add(colFileName);
var filelist = GetFileListOnWebServer().ToList();
var filenamesList = new BindingList<FileName>(filelist); // <-- BindingList
//Bind BindingList directly to the DataGrid, no need of BindingSource
gvFilesOnServer.DataSource = filenamesList
}

may be little late but useful for future. if you don't require to set custom properties of cell and only concern with header text and cell value then this code will help you
public class FileName
{
[DisplayName("File Name")]
public string FileName {get;set;}
[DisplayName("Value")]
public string Value {get;set;}
}
and then you can bind List as datasource as
private void BindGrid()
{
var filelist = GetFileListOnWebServer().ToList();
gvFilesOnServer.DataSource = filelist.ToArray();
}
for further information you can visit this page Bind List of Class objects as Datasource to DataGridView
hope this will help you.

I know this is old, but this hung me up for awhile. The properties of the object in your list must be actual "properties", not just public members.
public class FileName
{
public string ThisFieldWorks {get;set;}
public string ThisFieldDoesNot;
}

Instead of create the new Container class you can use a dataTable.
DataTable dt = new DataTable();
dt.Columns.Add("My first column Name");
dt.Rows.Add(new object[] { "Item 1" });
dt.Rows.Add(new object[] { "Item number 2" });
dt.Rows.Add(new object[] { "Item number three" });
myDataGridView.DataSource = dt;
More about this problem you can find here: http://psworld.pl/Programming/BindingListOfString

Using DataTable is valid as user927524 stated.
You can also do it by adding rows manually, which will not require to add a specific wrapping class:
List<string> filenamesList = ...;
foreach(string filename in filenamesList)
gvFilesOnServer.Rows.Add(new object[]{filename});
In any case, thanks user927524 for clearing this weird behavior!!