How to pass non-contiguous cells to Excel UDF - c#

in myUDF, I can reference a range of cells like "A1:A12", but how can I reference non-contiguous cells like "A1,B4,H3" etc.
I use ExcelDNA, the parameter type is object
but it seems it will take string, and a range of cells, not non-contiguous cells
[ExcelArgument(AllowReference = true, Name = "Relations", Description = "a set of relations")]object rels

It sounds like you're entering the formula onto the worksheet, along with its parameters, from your code, and you want users to then be able to edit the formula normally in Excel's formula bar. Is that correct?
If so, enclose the parameter in parens. For example, for a UDF like this...
Public Function MyUDF(my_param As Range)
'concatenate all cell values in a non-contiguous range:
Dim rgCell As Range, rgArea As Range
For Each rgArea In my_param.Areas
For Each rgCell In rgArea
MyUDF = MyUDF & CStr(rgCell.Value)
Next rgCell
Next rgArea
End Function
...enter it in the worksheet cell like this:
=MyUDF((A1,A3,A7:A11,C8:E10))
Note the extra set of parens compared to using a built-in function like SUM.
BTW as you may already know, when looping through a non-contiguous range you have to loop through the areas of the range, then loop through the cells in each area; looping through the cells in the range only gives you the cells in the first area.

Related

C# Interop, how to get the max length within a range of cells in Excel

I would like to get the max length within a range of cells in Excel using C# interop library.
I know that we can do it via in excel:-
1. =MAX(LEN(A2:A65636))
2. press ctrl+shft+enter after typing in the formula.
But I would like to do it using formula by my C# program.
Currently I am looping through all the cells within the column range and setting the maximum count. But it is taking lot of time for big excel file aroung 50000 rows.
I have tried even, setting the formula dynamically =MAX(LEN(A2:A rcnt))
But that doesn't work.
You can try to use the range.FormulaArray property to set formulas to a cell using C#.
For example:
Range r = activeWorksheet.get_Range("Y9",Type.Missing);
r.FormulaArray = "=MAX(LEN(D3:E3))";

Can Excel Ranges be jagged (rather than always contiguous)?

One can define ranges in C# Excel Interop like so:
var homeHomeOnTheRange = _xlSheet.Range[_xlSheet.Cells[3, 7], _xlSheet.Cells[42, 11]];
This range will encompass the subset of cells on the page from row 3 down to row 42, and across from columns 7 (or "G") through 11 (or "K").
What, though, if I want a "jagged" range - is it possible to concatenate an array of ranges into one range?
You can use this format sheet.Range("A1:A2,B2:B3,C3:C4").
Pay attention that sheet should be of type dynamic so don't use Worksheet class for this purpose.
Example
Set the specified range background color to red:
var range = sheet.Range("A1:A2,B2:B3,C3:C4");
range.Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);

Spreadsheetgear set data flags for specific column?

I am attempting to do this:
IWorksheet worksheet = Factory.GetWorkbook().Worksheets[0];
IRange range = worksheet.Cells["A1"];
range.CopyFromDataTable(dataTable, SetDataFlags.None);
worksheet.Cells.Columns.AutoFit();
return worksheet;
This works great normally, however I've run into an issue. I have one column that has a really long number, possibly with zeroes in the front and I need it to be entered and displayed as text. If I do a lookup of that particular cell like:
var cell = range["U34"].Value;
The data has already been turned into scientific notation so no amount of formatting afterwards fixes it. I tried SetDataFlags.AllText and that works great, except it breaks the rest of the worksheet because all of the numbers are stored as text, which is unacceptable.
I'm at a loss of how to fix this.
Solution:
Since I'm just looking to change one column, if it's present and a lot of the columns are dynamic I went with the "preformatting" route. Find the column index from the datatable:
int ColumnIndex = -1;
for (int x = 0; x < dataTable.Columns.Count; x++)
{
if (dataTable.Columns[x].ColumnName.Equals("Whatever"))
{
ColumnIndex = x;
}
}
worksheet.Cells[0, ColumnIndex, 0, ColumnIndex].EntireColumn.NumberFormat = "#";
Then perform the CopyFromDataTable, with Flags set to None and everything is perfect!
The IRange.CopyFromDataTable(...) method can be passed in a SetDataFlags.InsertCells enum option, which allows you to pre-format your destination range so that the inserted DataTable data picks up the formatting you specify. This formatting includes a cell's IRange.NumberFormat, which can be set to "#" and specifies that input to that cell should be treated as Text.
So, if you know what columns will have these unusually-large numbers that trigger scientific notation, another option would be to pre-format your worksheet's destination range with IRange.NumberFormat = "#" and will preserve your values for these columns as-is.
Please see the documentation for the IRange.CopyFromDataTable(...) method, as it provides important information on what range needs this "pre-formatting." Also, assuming you've installed SpreadsheetGear on your machine, check out the Reporting > DataSet to Workbook example in the SpreadsheetGear Explorer Solutions for C#/VB (found in the "SpreadsheetGear" folder under the Start Menu) for a live demo of this SetDataFlags.InsertCells option.

C# Interop Excel format like Excel's format as table

I'm exporting a table from SQLite to Excel (2010) in C#. It works fine. I'm using the Excel.Range.set_Value() method.
How can I format an Excel.Range like Excel's format (like a table) would?
To expand upon my comment and add to D Stanley.
Range range = ws.get_Range("A1:D5");
wrksheet.ListObjects.AddEx(XlListObjectSourceType.xlSrcRange, range, missing, Microsoft.Office.Interop.Excel.XlYesNoGuess.xlNo, missing).Name = "MyTableStyle";
wrksheet.ListObjects.get_Item("MyTableStyle").TableStyle = "TableStyleMedium1";
This example selects a rectangular range of every cell in the active sheet. Also, it uses indexed parameters of Range to get the range points. Furthermore, AddEx() (and most methods in Interop.Excel) uses default parameters so you don't have to use System.Reflection.Missing.
// define points for selecting a range
// point 1 is the top, leftmost cell
Excel.Range oRng1 = oSheet.Range["A1"];
// point two is the bottom, rightmost cell
Excel.Range oRng2 = oSheet.Range["A1"].End[Excel.XlDirection.xlToRight]
.End[Excel.XlDirection.xlDown];
// define the actual range we want to select
oRng = oSheet.Range[oRng1, oRng2];
oRng.Select(); // and select it
// add the range to a formatted table
oRng.Worksheet.ListObjects.AddEx(
SourceType: Excel.XlListObjectSourceType.xlSrcRange,
Source: oRng,
XlListObjectHasHeaders: Excel.XlYesNoGuess.xlYes);
Here's the VBA that does it:
ActiveSheet.ListObjects.Add xlSrcRange, Range("$J$10:$N$12"), , xlYes
Shouldn't be too hard to translate into an automation call. You can read the documentation as well.

In C#, how do I use the Excel Interop to speed up writing several cell values

I have a piece of hardware for which I am getting 30 data points. Each of these points is recorded in a spreadsheet at several different places before the sheet is made visible, then another program takes over the excel spreadsheet. It is required all these values are written to the spreadsheet before the other program takes over. If I write each cell individually, the writes are taking approximately 50ms, which takes about 1.25 seconds to complete the data acquisition.
If I could write all the values to the spreadsheet at one time, I feel this will significantly speed up the writing of all these cells. The problem I see is that Ranges work very well for updating contiguous cells where as my data isn't contiguous. Essentially, this would be an example of what I want to write:
A1 = 1
B23 = a
F8 = 2012/12/25
D53 = 4.1235
B2 = 5
I have tried creating a range of "A1,B23,F8,D53,B2", then set the values using an array of values. I tried 3 different arrays: object[5], object[1,5], and object[5,1]. These all set the values of the specified cells in the range to the first index of the array I created in all cases.
Is there a way to update these 30 cells data without iterating through the cells one at a time?
Thanks,
Tom
If your architecture would permit, another idea is using a hidden sheet with a continuous rectangular range, set names to its parts and use these names on all other sheets.
I would define a rectangular range object that includes all the cells whose values you want to modify. Get a rectangular object[,] array from that range's value property. Write the new values to the array, and then set the range's value using the modified array.
You could write the values to contiguous cells that are somewhere out of the way, say in column X, and have formulae in the target cells that refer to these updated cells. So cell A1 would have the formula "=X1", cell B23 "=X2" and so on.

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