Develop Reference

C# Excel VSTO can not convert string to String.Array

I am new to VSTO C# excel add-in. I am looking to find total count of not null/empty rows in a range. My Code looks at the range "A4:E4" and count total number of rows.
This is the code :
private void button1_Click(object sender, RibbonControlEventArgs e)
{
Workbook workbook = Globals.ThisAddIn.GetWorkBook("c:\\temp\\testfile.xlsx");
Worksheet mergeSheet = workbook.Worksheets["Data"];
Excel.Range mergeCells = mergeSheet.Range["A4:E4"];
var colValues = (System.Array)mergeCells.Columns[1].Cells.Value;
var strArray = colValues.OfType<object>().Select(o => o.ToString()).ToArray();
var rowCount = strArray.Length;
}
[public Excel.Workbook GetWorkBook(string pathName)
{
return (Excel.Workbook)Application.Workbooks.Open(pathName);
}][1]
I get error var colValues = (System.Array)mergeCells.Columns[1].Cells.Value;on line :
Microsoft.CSharp.RuntimeBinder.RuntimeBinderException: 'Cannot convert type 'string' to 'System.Array''
It works when I have two rows in my range. I have hardcoded range A4:E4 to produce the error. My excel sheet (testfile.xlsx) looks like below:
Any ideas how do I resolve this?
Same line of code works when I have two rows. Eg and following line is updated
Excel.Range mergeCells = mergeSheet.Range["A4:E5"];

The problem is that Range.Value can return different types of objects. Among others, it can return
a single value of type String, if the range contains a single cell containing a string or
an array of values, if the range contains more than one cell.
The simplest solution would be to count the number of cells and "wrap" the special "single value" case in an array:
var range = mergeCells.Columns[1].Cells;
var values = (range.Count == 1)
? new object[] { range.Value })
: ((Sytem.Array)range.Value).Cast<object>();

This line is causing me trouble, var colValues = (System.Array)mergeCells.Columns[1].Cells.Value
This row has only one value. Note that same line works when mergeCells range has two rows.
Why it does not work for single cell range:
The Value of a single cell is not an array (it's a Long, String, DateTime, etc.) and won't be cast to an array in that manner. You can see this by testing like below:
var myArray = (System.Array)"hello"
This will give same failure for other types:
Why it works for multi-cell range:
The Value of a multi-cell range will return a variant array of the individual cell values, which either is, or can be cast to a System.Array
There may be a better resolution, but at least you should be able to do like:
var colValues;
if (mergeCells.Columns[1].Cells.Count > 1)
{
colValues = (System.Array)mergeCells.Columns[1].Cells.Value;
}
else
{
// NB: you may need to cast other data types to string
// or you could use .Cells[0].Text.Split()
colValues = (System.Array)mergeCells.Columns[1].Cells[0].Value.Split();
}

Seeing if comment in cell is null using Excel interlop c#.net

Hey all I am using the code below in order to find out if a cell in the Excel sheet that I am parsing thru has a comment or not.
int columnCount = ws.UsedRange.Columns.Count;
Dictionary<string,bool> storedValidaters = new Dictionary<string, bool>();
for (int c = 1; c < columnCount; c++)
{
if (ws.Cells[2, c].Comment.Shape.AlternativeText != null)
{
string columnName = ws.Cells[2, c].Value2.ToString();
string myComment = ws.Cells[2, c].Comment.Shape.AlternativeText.ToString().Replace("Text Box: ", "");
storedValidaters.Add(columnName, true);
} else {
//the value is null so its false
string columnName = ws.Cells[2, c].Value2.ToString();
storedValidaters.Add(columnName, false);
}
}
It loops a few times but once it gets to a cell that does not have a comment, it poops.
Having the error of Cannot perform runtime binding on a null reference.
I did a few searches to find out if anyone else had working code in order to check for null but have been unable to find a working example.
Anyone know of a way to do this?

I would recommend changing:
Comment.Shape.AlternativeText
to:
Comment?.Shape?.AlternativeText
The null conditional operator will ensure that the code will continue to work as expected regardless of whether the Comment is null, or the Shape is null or the AlternativeText is null.

How to get format type of cell using c# in spreadsheetlight

I am using spreadsheetlight library to read Excel sheet(.xslx) values using c#.
I can read the cell value using following code
for (int col = stats.StartColumnIndex; col <= stats.EndColumnIndex; col++)
{
var value= sheet.GetCellValueAsString(stats.StartRowIndex, col); //where sheet is current sheet in excel file
}
I am getting the cell value. But how can I get the data type of the cell? I have checked in documentation but didn't find the solution.
Note: For .xls type of excel files i am using ExcelLibrary.dll library where i can easily get the datatype of cells using below code
for (int i = 0; i <= cells.LastColIndex; i++)
{
var type = cells[0, i].Format.FormatType;
}
but there is no similar method in spreadsheetlight.

Here is the answer from the developer Vincent Tang after I asked him as I wasn't sure how to use DataType:
Yes use SLCell.DataType. It's an enumeration, but for most data, you'll be working with Number, SharedString and String.
Text data will be SharedString, and possibly String if the text is directly embedded in the worksheet. There's a GetSharedStrings() or something like that.
For numeric data, it will be Number.
For dates, it's a little tricky. The data type is also Number (ignore the Date enumeration because Microsoft Excel isn't using it). For dates, you also have to check the FormatCode, which is in the SLStyle for the SLCell. Use the GetStyles() to get a list. The SLCell.StyleIndex gives you the index to that list.
For example, if your SLCell has cell value "15" and data type SharedString, then look for index 15 in the list of shared strings. If it's "blah" with String data type, then that's it.
If it's 56789 with Number type, then that's it.
Unless the FormatCode is "mm-yyyy" (or some other date format code), then 56789 is actually the number of days since 1 Jan 1900.
He also recommended using GetCellList() in order to obtain the list of SLCell objects in the sheet. However, for some reason that function was not available in my version of SL, so I used GetCells() instead. That returns a dictionary of SLCell objects, with keys of type SLCellPoint.
So for example to get the DataType (which is a CellValues object) of cell A1 do this:
using (SLDocument slDoc = new SLDocument("Worksheet1.xlsx", "Sheet1")) {
slCP = SLCellPoint;
slCP.ColumnIndex = SLConvert.ToColumnIndex("A"); ///Obviously 1 but useful function to know
slCP.RowIndex = 1;
CellValues slCV = slDoc.GetCells(slCP).DataType;
}
By the way, I also had a problem with opening the chm help file. Try this:
Right Click on the chm file and select properties
Click on Unblock button at the bottom of the General Tab

To get the value of the cell try following code
var cellValue = (string)(excelWorksheet.Cells[10, 2] as Excel.Range).Value;
Use this link for more details

Check out the SLCell.DataType Property. Spreadsheetlight documentation mentions that this returns the Cell datatype, in class Spreadsheetlight.SLCell
public CellValues DataType { get; set; }
PS: On a side note, I figured out how to open the chm documentation. Try opening the chm file in Winzip, it opens without any issues.
Hope it helps. Thanks

Well, After a lot of trail and error methods i got to find a solution for this.
Based on the formatCode of a cell we can decide the formatType of the cell.
Using GetCellStyle method we can get the formatcode of the cell. Using this formatCode we can decide the formatType.
var FieldType = GetDataType(sheet.GetCellStyle(rowIndex, columnIndex).FormatCode);
private string GetDataType(string formatCode)
{
if (formatCode.Contains("h:mm") || formatCode.Contains("mm:ss"))
{
return "Time";
}
else if (formatCode.Contains("[$-409]") || formatCode.Contains("[$-F800]") || formatCode.Contains("m/d"))
{
return "Date";
}
else if (formatCode.Contains("#,##0.0"))
{
return "Currency";
}
else if (formatCode.Last() == '%')
{
return "Percentage";
}
else if (formatCode.IndexOf("0") == 0)
{
return "Numeric";
}
else
{
return "String";
}
}
This method worked for 99% of the cases.
Hope it helps you.

Get textbox value from Excel cell

A user has provided me with an Excel document that has textboxes in a few of the cells. I have the usual setup code to load the Excel application, get the worksheet, and then start iterating the used range. When I try to get the value of the cell that contains the textbox, the value is null.
foreach (Range row in usedRange.Rows) {
object[,] valueArray = (object[,])row.get_Value(XlRangeValueDataType.xlRangeValueDefault);
var value = valueArray[1,10]; // This is null for textbox cells
}
Is there a special method I should use to get the value of the textbox that appears in an Excel worksheet?
Edit with fix and explanation
Stewbob's suggestion of iterating the shapes got me in the right direction. But using the following code, I was getting null exceptions:
for (int i=1; i<shapes.Count;i++){
var item = shapes.Range[i].Item(1);
string myString = item.TextFrame2.TextRange.Characters.Text.ToString();
}
After looking at the object in Quickwatch, I noticed something odd about the shape. It was of type msoOLEControlObject. It turns out the values on this Excel document are cut and pasted into Excel from a webpage. Excel was not creating textboxes but OLE boxes. The OLE box did have a 'Value' property so I could access the textboxes value as such:
var shapes = ws.Shapes;
for (int i=1; i<shapes.Count;i++){
var item = shapes.Range[i].Item(1);
var myText = item.OLEFormat.Object;
if (myText.Object != null) {
if (myText.Object.Value != null) {
Console.WriteLine(myText.Object.Value.ToString());
}
}
}
So make sure if you are dealing with pasted objects that you check the value property and not the TextRange property.

If you know the name of the Text Box, you can reference it this way:
ActiveSheet.Shapes.Range(Array("TextBox 1")).Select
If you don't know the name, you can use ActiveSheet.Shapes to iterate through all the shapes on the worksheet.
Getting to the actual text in the TextBox is not very straightforward in VBA. The following code iterates through all the Shape objects on the active worksheet:
Dim shp As Shape
Dim myText As String
For Each shp In ActiveSheet.Shapes
myText = shp.TextFrame2.TextRange.Characters.Text
Next
Though I see that you are working in C#, so the above code will be a little different, but it at least gives you the object model to get to the text inside the TextBox.

Well, the TextBox isn't actually inside any cell (although it may appear to be).
Instead, you have to get it from the Shapes collection in the WorkSheet.

Read data from combined Excel columns/rows using C#

I'm trying to read data from an Excel document in C# using Microsofts COM Interop.
So far, I'm able to load the document and read some data from it. However, I need to read data from two different columns and output these as json (for a jquery ajax call)
I've made a quick prototype of how my Excel document is structured with the hope that it's a bit easier to explain ;-)
The method I have is called GetExcelDataByCategory(string categoryName) where the categoryName parameter would be used to find which column to get the data from.
So, i.e., if I'm making the call with "Category 2" as parameter, I need to get all the values in the C columns rows and the corresponding dates from the A column, so the output will look like this:
Which then needs to be transformed/parsed into JSON.
I've searched high and low on how to achieve this, but with no luck so far :-( I'm aware that I can use the get_Range() method to select a range, but it seems you need to explicitly tell the method which row and which column to get the data from. I.e.: get_Range("A1, C1")
This is my first experience with reading data from an Excel document, so I guess there's a lot to learn ;-) Is there a way to get the output on my second image?
Any help/hint is greatly appreciated! :-)
Thanks in advance.
All the best,
Bo

This is what I would do:
using Excel = Microsoft.Office.Interop.Excel;
Excel.Application xlApp = new Excel.Application();
Excel.Workbook xlWorkbook = xlApp.Workbooks.Open("path to book");
Excel.Worksheet xlSheet = xlWorkbook.Sheets[1]; // get first sheet
Excel.Range xlRange = xlSheet.UsedRange; // get the entire used range
int numberOfRows = xlRange.Rows.Count;
int numberOfCols = xlRange.Columns.Count;
List<int> columnsToRead = new List<int>();
// find the columns that correspond with the string columnName which
// would be passed into your method
for(int i=1; i<=numberOfCols; i++)
{
if(xlRange.Cells[1,i].Value2 != null) // ADDED IN EDIT
{
if(xlRange.Cells[1,i].Value2.ToString().Equals(categoryName))
{
columnsToRead.Add(i);
}
}
}
List<string> columnValue = new List<string>();
// loop over each column number and add results to the list
foreach(int c in columnsToRead)
{
// start at 2 because the first row is 1 and the header row
for(int r = 2; r <= numberOfRows; r++)
{
if(xlRange.Cells[r,c].Value2 != null) // ADDED IN EDIT
{
columnValue.Add(xlRange.Cells[r,c].Value2.ToString());
}
}
}
This is the code I would use to read the Excel. Right now it reads every column that has the heading (designated by whatever is in the first row) and then all the rows there. It isn't exactly what you asked (it doesn't format into JSON) but I think it is enough to get you over the hump.
EDIT: Looks like there are a few blank cells that are causing problems. A blank cell will be NULL in the Interop and thus we get errors if we try to call Value2 or Value2.ToString() since they don't exist. I added code to check to make sure that the cell isn't null before doing anything with it. It prevent the errors.

for Excel-parsing and creation you can use ExcelDataReader: http://exceldatareader.codeplex.com/
and for json you can use json.net: http://json.codeplex.com/
Both are fairly easy to use. Just have a look at the websites.