Excel read in CVI

Question

I just open the excel file as 'string' in CVI.
I already read http://forums.ni.com/t5/LabWindows-CVI/How-do-I-allocate-memory-for-excel-strings/m-p/754813#M37082
However, I cannot understand it  T-T because I am poor at programming.
Does any guys teach how to open the excel file and appear at table in CVI UI.
Solved!
Go to Solution.

Answer 1

Hi! Babemin,
You need to study the example CVI project "excel2000dem.prj" that comes with your LabWindows/CVI.  Closely investigate the function "ReadDataFromExcel(....)" in the C program "excel2000dem.c".  The first method in this function read each individual cell in the opened Excel file and print out the value of that cell directly on screen.  This example shows you how to read multiple double values from an Excel file "exceldem.xls".  If you don't study this project, you will not be able to complete your task.
Assuming you understand the example program already, open this "exceldem.xls" file manually and add a text "myText1" to cell B35.  Close and save the excel file.
You can then add the following code into the function "ReadDataFromExcel(....)" in the C program "excel2000dem.c" before the label "Error:".  Be sure to add a new declaraction "char *str;" in the function. 
// Open and activate one cell only
    error = CA_VariantSetCString (&MyCellRangeV, "B35");
    error = Excel_WorksheetRange (ExcelWorksheetHandle, NULL, MyCellRangeV, CA_DEFAULT_VAL, &ExcelSingleCellRangeHandle);
    if (error<0) goto Error;
    // Make range Active
    error = Excel_RangeActivate (ExcelSingleCellRangeHandle, &ErrorInfo, NULL);
    if (error<0) goto Error;
            // Get the value of the Single Cell Range
            error = Excel_GetProperty (ExcelSingleCellRangeHandle, &ErrorInfo, Excel_RangeValue2, CAVT_VARIANT, &MyVariant);
            if (error<0) goto Error;
            if (!CA_VariantHasCString(&MyVariant))
                MessagePopup(APP_WARNING, "Values returned were not of type character string.");
                goto Error;
            error = CA_VariantGetCString(&MyVariant, &str);
            if (error<0) goto Error;
            // Free Variant element
            CA_VariantClear(&MyVariant);
            printf("%s\n ", str);
Now run the project again.  Click "Read Data" in the front panel and you'll see it reads and prints "myText1" on the screen.
This is the method to read a text string from a known cell position in an Excel file.