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How I write to the file from datagridview

Am trying to write from the datagridview with a goal of saving the input to the xml file, but am not getting it correctly. My code:
XDocument doc = XDocument.Load(outputFilePath);
doc.Save(outputFilePath);
oDataSet = new DataSet();
foreach (DataGridViewRow _rows in Gridview_Output.Rows)
{
DataRow oDatarow = oDataTable.NewRow();
for (int i = 0; i < Gridview_Output.ColumnCount; i++)
{
oDataTable.Rows.Add(oDatarow.ItemArray);
}
}
oDataSet.Tables.Add(oDataTable);
oDataSet.WriteXml(outputFilePath);
doc.Save(outputFilePath);
I want to write to this empty tags:
<data name="Exit_Button" xml:space="preserve">
<value></value>
<comment>[Font][/Font][DateStamp][/DateStamp][Comment][/Comment]</comment>
</data>

Hmm try this to create a datatable from gridview:
private DataTable GetDataTableFromDGV(DataGridView dgv) {
var dt = new DataTable();
foreach (DataGridViewColumn column in dgv.Columns) {
if (column.Visible) {
// You could potentially name the column based on the DGV column name (beware of dupes)
// or assign a type based on the data type of the data bound to this DGV column.
dt.Columns.Add();
}
}
object[] cellValues = new object[dgv.Columns.Count];
foreach (DataGridViewRow row in dgv.Rows) {
for (int i = 0; i < row.Cells.Count; i++) {
cellValues[i] = row.Cells[i].Value;
}
dt.Rows.Add(cellValues);
}
return dt;
}
Then you can do:
DataTable dT = GetDataTableFromDGV(DataGridView1);
DataSet dS = new DataSet();
dS.Tables.Add(dT);
dS.WriteXml(File.OpenWrite("xml.xml"));

C# List<string>[] to Datatable

I need to convert a list array of type List<string>[] to Datatable in C#.
I have found many topics related to List<string[]> to Datatable conversion but nothing on the conversion I need.
Pseudocode:
//Retrieve data from MySQL server
db.Select(category, productID);
//populate List<string>[] array
list[0] = db.ListQuery[0];
list[1] = db.ListQuery[1];
//convert list[] to Datatable
.....
Any help is much appreciated.

If I'm understanding your question right, do you mean something like this?
string category = "Category";
string productId = "ProductId";
List<string[]> tempList = db.Select(category, productID); //Not necessarily correct (I'm not familiar with MySQL). Do what you need to do to create the List<string[]>
DataTable table = new DataTable();
DataRow row;
table.Columns.Add(category);
table.Columns.Add(productId);
foreach (string[] s in tempList)
{
row = table.NewRow();
row[category] = s[0];
row[productId] = s[1];
table.Rows.Add(row);
}

DataTable dataTable = new DataTable();
List<MemberInfo> props = typeof(T).GetFields().Select(objField => (MemberInfo)objField).ToList();
props.AddRange(typeof(T).GetProperties().Select(objField => (MemberInfo)objField));
if (props.Count > 0)
{
Type t;
bool tIsField = false;
for (int iCnt = 0; iCnt < props.Count; iCnt++)
{
var prop = props[iCnt];
tIsField = prop.MemberType == MemberTypes.Field;
dataTable.Columns.Add(prop.Name, tIsField ? ((FieldInfo)prop).FieldType : ((PropertyInfo)prop).PropertyType);
}
foreach (T item in data)
{
DataRow dr = dataTable.NewRow();
foreach (var field in props)
{
tIsField = field.MemberType == MemberTypes.Field;
object value = tIsField ? ((FieldInfo)field).GetValue(item) : ((PropertyInfo)field).GetValue(item, null);
dr[field.Name] = value;
}
dataTable.Rows.Add(dr);
}
}
return dataTable;

Convert select new to DataTable?

I am using .NET 3.5 and need to convert the below select new result into a DataTable. Is there something built in for this or anyone know of a method that can do this?
var contentList = (from item in this.GetData().Cast<IContent>()
select new
{
Title = item.GetMetaData("Title"),
Street = item.GetMetaData("Street"),
City = item.GetMetaData("City"),
Country = item.GetMetaData("Country")
});

Easy and straightforward thing to do is to use reflection:
var records = (from item in this.GetData().Cast<IContent>()
select new
{
Title = "1",
Street = "2",
City = "3",
Country = "4"
});
var firstRecord = records.First();
if (firstRecord == null)
return;
var infos = firstRecord.GetType().GetProperties();
DataTable table = new DataTable();
foreach (var info in infos) {
DataColumn column = new DataColumn(info.Name, info.PropertyType);
table.Columns.Add(column);
}
foreach (var record in records) {
DataRow row = table.NewRow();
for (int i = 0; i < table.Columns.Count; i++)
row[i] = infos[i].GetValue(record);
table.Rows.Add(row);
}
Code may not be working up front but should give you a general idea. First, you get propertyInfos from anonymous type and use this metadata to create datatable schema (fill columns). Then you use those infos to get values from every object.

Here is one generic solution without Reflecting over the properties. Have an extension method as below
public static DataTable ConvertToDataTable<TSource>(this IEnumerable<TSource>
records, params Expression<Func<TSource, object>>[] columns)
{
var firstRecord = records.First();
if (firstRecord == null)
return null;
DataTable table = new DataTable();
List<Func<TSource, object>> functions = new List<Func<TSource, object>>();
foreach (var col in columns)
{
DataColumn column = new DataColumn();
column.Caption = (col.Body as MemberExpression).Member.Name;
var function = col.Compile();
column.DataType = function(firstRecord).GetType();
functions.Add(function);
table.Columns.Add(column);
}
foreach (var record in records)
{
DataRow row = table.NewRow();
int i = 0;
foreach (var function in functions)
{
row[i++] = function((record));
}
table.Rows.Add(row);
}
return table;
}
And Invoke the same using where parameters will be the column name in the order you want.
var table = records.ConvertToDataTable(
item => item.Title,
item => item.Street,
item => item.City
);

You can convert your list result to datatable by the below function
public static DataTable ToDataTable<T>(IEnumerable<T> values)
{
DataTable table = new DataTable();
foreach (T value in values)
{
if (table.Columns.Count == 0)
{
foreach (var p in value.GetType().GetProperties())
{
table.Columns.Add(p.Name);
}
}
DataRow dr = table.NewRow();
foreach (var p in value.GetType().GetProperties())
{
dr[p.Name] = p.GetValue(value, null) + "";
}
table.Rows.Add(dr);
}
return table;
}

There is a CopyToDataTable extension method which does that for you. It lives in System.Data.DataSetExtensions.dll

Try this:
// Create your datatable.
DataTable dt = new DataTable();
dt.Columns.Add("Title", typeof(string));
dt.Columns.Add("Street", typeof(double));
// get a list of object arrays corresponding
// to the objects listed in the columns
// in the datatable above.
var result = from item in in this.GetData().Cast<IContent>()
select dt.LoadDataRow(
new object[] { Title = item.GetMetaData("Title"),
Street = item.GetMetaData("Street"),
},
false);
// the end result will be a set of DataRow objects that have been
// loaded into the DataTable.
Original Article for code sample : Converting Anonymous type generated by LINQ to a DataTable type
EDIT: Generic Pseudocode:
void LinqToDatatable(string[] columns, Type[] datatypes, linqSource)
{
for loop
{
dt.columns.add(columns[i], datatypes[i]);
}
//Still thinking how to make this generic..
var result = from item in in this.GetData().Cast<IContent>()
select dt.LoadDataRow(
new object[] { string[0] = item.GetMetaData[string[0]],
string[1] = item.GetMetaData[srring[1]
},
false);
}

public static DataTable ListToDataTable<T>(this IList<T> data)
{
DataTable dt = new DataTable();
PropertyDescriptorCollection props = TypeDescriptor.GetProperties(typeof(T));
for (int i = 0; i < props.Count; i++)
{
PropertyDescriptor prop = props[i];
dt.Columns.Add(prop.Name, prop.PropertyType);
}
object[] values = new object[props.Count];
foreach (T t in data)
{
for (int i = 0; i < values.Length; i++)
{
values[i] = props[i].GetValue(t);
}
dt.Rows.Add(values);
}
return dt;
}
After you do your select new you can to .ToList().ListToDataTable(). This uses ComponentModel reflection and is (theroetically) faster than System.Reflection.

Merge datatables but ignore duplicated rows

I have the following code, its a custom people picker for sharepoint 2010.
It searches by username, but also by the person name.
Because its a contains search, if I try with part of my username: cia
It shows my duplicated rows because that matches the username but also the person name.
this is my code (I cant use LINQ:
protected override int IssueQuery(string search, string groupName, int pageIndex, int pageSize)
{
try
{
// Find any user that has a matching name
var table = ADHelper.ExecuteNameQuery(RootPath, search);
// 20249: Search by username, method was already done, but it was not being called.
var table2 = ADHelper.ExecutesAMAccountNameQuery(search);
table2.Merge(table,);
PickerDialog.Results = table2;

Normally the DataTable.Merge method removes duplicates implicitely. But only when all columns' values are the same.
I'm not sure if there is something simplier(you've mentioned that you cannot use LINQ), but you could merge both and remove the duplicates afterwards:
List<string> dupColumns = new List<string>();
dupColumns.Add("ColumnA");
dupColumns.Add("ColumnB");
table2.Merge(table,);
RemoveDuplicates(table2, dupColumns);
And here the remove-duplicates function:
private void RemoveDuplicates(DataTable table, List<string> keyColumns)
{
Dictionary<string, string> uniquenessDict = new Dictionary<string, string>(table.Rows.Count);
System.Text.StringBuilder sb = null;
int rowIndex = 0;
DataRow row;
DataRowCollection rows = table.Rows;
while (rowIndex < rows.Count)
{
row = rows[rowIndex];
sb = new System.Text.StringBuilder();
foreach (string colname in keyColumns)
{
sb.Append(((string)row[colname]));
}
if (uniquenessDict.ContainsKey(sb.ToString()))
{
rows.Remove(row);
}
else
{
uniquenessDict.Add(sb.ToString(), string.Empty);
rowIndex++;
}
}
}

you should the .ToTable function
here is a sample code
DataTable DT1 = new DataTable();
DT1.Columns.Add("c_" + DT1.Columns.Count);
DT1.Columns.Add("c_" + DT1.Columns.Count);
DT1.Columns.Add("c_" + DT1.Columns.Count);
DataRow DR = DT1.NewRow();
DR[0] = 0;
DR[1] = 1;
DR[2] = 2;
DT1.Rows.Add(DR);
DataTable DT2 = new DataTable();
DT2.Columns.Add("c_" + DT2.Columns.Count);
DT2.Columns.Add("c_" + DT2.Columns.Count);
DT2.Columns.Add("c_" + DT2.Columns.Count);
DT2.Columns.Add("c_" + DT2.Columns.Count);
DR = DT2.NewRow();
DR[0] = 0;
DR[1] = 1;
DR[2] = 2;
DR[3] = 3;
DT2.Rows.Add(DR);
DT1.Merge(DT2);
Trace.IsEnabled = true;
DataTable DT_3=DT1.DefaultView.ToTable(true,new string[]{"c_1","c_2","c_0"});
foreach (DataRow CDR in DT_3.Rows)
{
Trace.Warn("val",CDR[1]+"");//you will find only one data row
}

How to 'foreach' a column in a DataTable using C#?

How do I loop through each column in a datarow using foreach?
DataTable dtTable = new DataTable();
MySQLProcessor.DTTable(mysqlCommand, out dtTable);
foreach (DataRow dtRow in dtTable.Rows)
{
//foreach(DataColumn dc in dtRow)
}

This should work:
DataTable dtTable;
MySQLProcessor.DTTable(mysqlCommand, out dtTable);
// On all tables' rows
foreach (DataRow dtRow in dtTable.Rows)
{
// On all tables' columns
foreach(DataColumn dc in dtTable.Columns)
{
var field1 = dtRow[dc].ToString();
}
}

I believe this is what you want:
DataTable dtTable = new DataTable();
foreach (DataRow dtRow in dtTable.Rows)
{
foreach (DataColumn dc in dtRow.ItemArray)
{
}
}

You can do it like this:
DataTable dt = new DataTable("MyTable");
foreach (DataRow row in dt.Rows)
{
foreach (DataColumn column in dt.Columns)
{
if (row[column] != null) // This will check the null values also (if you want to check).
{
// Do whatever you want.
}
}
}

You can check this out. Use foreach loop over a DataColumn provided with your DataTable.
foreach(DataColumn column in dtTable.Columns)
{
// do here whatever you want to...
}

Something like this:
DataTable dt = new DataTable();
// For each row, print the values of each column.
foreach(DataRow row in dt .Rows)
{
foreach(DataColumn column in dt .Columns)
{
Console.WriteLine(row[column]);
}
}
http://msdn.microsoft.com/en-us/library/system.data.datatable.rows.aspx

In LINQ you could do something like:
foreach (var data in from DataRow row in dataTable.Rows
from DataColumn col in dataTable.Columns
where
row[col] != null
select row[col])
{
// do something with data
}

int countRow = dt.Rows.Count;
int countCol = dt.Columns.Count;
for (int iCol = 0; iCol < countCol; iCol++)
{
DataColumn col = dt.Columns[iCol];
for (int iRow = 0; iRow < countRow; iRow++)
{
object cell = dt.Rows[iRow].ItemArray[iCol];
}
}