Add A "properties" Data Structure To An Excel Object?
Sep 24, 2009
I'm writing a VB app to do stuff with some existing spreadsheets. I'd like to add a "properties" data structure to an Excel object and have two options:
1.
class ExcelPlusPlus
Dim properties As HashTable
Dim xlobj As Excel.Application
End Class
2.
class ExcelPlusPlus
Inherits Excel.Application
[code]....
I much prefer solution 2, as ExcelPlusPlus should respond exactly as Excel.Application.However, Visual Studio (2005) errors out on the "Inherits..." line saying "Classes can inherit only from other classes"
I'm new to VB 2008 after having spent a long time with VB6, so I apologize if this is a stupid question. But I'd really like to have this straightened out.
Let's say I have a pretty large structure that has lots of properties.
Code:
Now say that I want an internal database with about 10 instances of this structure total, describing, say, 10 different products that a store sells. When these values are loaded from a database, they remain totally static. (However, they can be different each time a program loads)
Now say that I have a class. Each instance of this class is a type of that BaseProduct structure. Meaning, each instance of the class pertains to one of the 10 types of products that the store sells. However, this class has additional properties that pertain specifically to each instance, which are not static.
Code:
Now, the problem here is... If I have 200 different transactions, each one contains an instance of BaseProduct. BaseProduct is HUGE, and is largely redundant (only 10 types possible), so I think it's a little silly to include a whole copy of it with EVERY transaction. However, the Transaction class really needs information regarding the base product it pertains to. Is there a way to, instead of declaring a New BaseProduct in the Transaction class, to simply make one of the properties of the Transaction class a pointer to a BaseProduct variable?
In VB6, I would accomplish this by making a BaseProduct(10) array, and then giving each Transaction an ID number referring to an entry in that array. But in VB 2008, using class structure, this is impossible. I can't define the BaseProduct(10) array outside of a class in a namespace, and if I define it in the actual application's form, then the class loses modularity since it relies on the application that's using it.
I have a need to populate a data object containing 30+ properties from a database table. I could create a simple class containing a public variable for each of the required properties, but I don't want to.
Is the following code a bad idea:
<Serializable()> Public Class DtoEmployee Public EmployeeId As String
Let's say I have an employee class with ID, Forename, Surname, Initials and Email Address properties.
At present, you can construct an Employee object by passing a data row which, typically will include all these fields. However, sometimes I only want the ID, Forename and Surname but still want to populate an object.
[Code]...
However obviously if certain fields are not present in the data row, I will have an error. Is there a quick way of populating the object based on the fields that are present within the data row without a) having to have separate subs for each circumstance and b) without having to try / catch (or something similar) around each property? I know other languages have options like this - where if there is no value, it will be another value (i.e. a default).
Im doing my first project with WinForms, and Im trying to get the DataBinding working. Theres no database in my project, but I'd like to bind some of the TextBoxes to objects' properties. In the other section of this forum (here) I found this line of C# code which does it: textBox2.DataBindings.Add(new Binding("Text", this.myPerson, "LastName"));
my question is can data binding to object properties be set up during design time (without writing code)? If so, how? P.S. I know how I would set up this binding if in WPF, but I'm forced to use WinForms.
I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj Inherits baseObj Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
I am using asp.net with vb for my scripts.I want to use an array of a Structure to store data parsed from an xml file.[code]All appears to work fine until I add the code that is in bold, I then get the Object reference not set to an instance of an object.
and it throws me an exception. I'm feeling that I'm doing something wrong with the object access, but this method worked in embedded VB, and do not works in .net.
How do I link data in an Excel spreadsheet to a chart object in Visual Basic 2010? Really basic here, I just want to draw a single simple line chart from a single column of data. Is it easier just to read the data into an array (which I can do) and somehow get it into the chart?
I have an enum that I want to give some methods. I thought about changing the enum to a structure so I could add properties, but then the enum is a value inside the structure (not the structure itself), so this would affect comparisons and such. (For example, instead of writing EnumVariable=EnumConstant, Now it is StructureVariable.EnumValue=EnumConstant). At least, this is my understanding of it. It seems awkward to have to do this for such a simple scenario, so is it possible give enums properties, yet still have them treated as before? I've thought maybe I need to create a new valuetype from scratch, but I've never done that before.
How do I link data in an Excel spreadsheet to a chart object in Visual Basic 2010? Really basic here....I just want to draw a single simple line chart from a single column of data. Is it easier just to read the data into an array (which I can do) and somehow get it into the chart?
I am having some trouble using Refelction to list the properties of a user defined structure. I need to get a list of the properties and their values.[code]
I want to build a MVC helper function for which I pass a Entity Framework object and have it build a select. Generally speaking I tried something like this:
Public Function RenderSelect(ByVal helper As HtmlHelper, ByVal sSelectName As String, ByVal aItmes As Array, Optional ByVal sTitleKeyName As String = "name", Optional ByVal sValueKeyName As String = "id") As String ' open select
[Code].....
However, it isn't working. It would be great to have a way to do this and pass the current entity object.
I am passing a pair of serialized objects into a vb.net webserviceThe first one maps to a known structure, so I am using the structure type in the parameter list of the webservice. The second object may map to one of 6+ structures.A field in the first object will tell me which structure to use for the second object once both objects are passed to the webservice.
We are busy with a TabControl1 with 5 tabs. On these 5 tabs will be made the exact the same object structure with the same script.What is the best way to organize the TabControl1.
We are busy with a TabControl1 with 5 tabs. On these 5 tabs will be made the exact the same object structure with the same script.What is the best way to organize the TabControl
I am using VS .net 2003 and developing a program that calls Excel. The development computer only has Excel 2003, and the target machine only has Excel 2007. Would it be possible to install Excel 12 Object Library in the development computer without installing Excel 2007?
I'm trying to upgrade a VB6 app to VB 2008. I have read the article in the tutors corner about automating Excel from VB but I cannot get it to work. Heres what I have done:
1) set a reference to the Microsoft Excel 12.0 Object Library
2) Added "Imports Excel = Microsoft.Office.Interop.Excel" to the top of the module
3) in a routine I have added: Dim X As New Excel.Application Here's where I get an error: Error 75 'Application' is ambiguous in the namespace 'Microsoft.Office.Interop.Excel'.
Dim exlapp As New Microsoft.Office.Interop.Excel.Application Dim xlWorkBook_new As Microsoft.Office.Interop.Excel.Workbook Dim strOriginal As String strOriginal = Server.MapPath(Request.ApplicationPath & "/Attachments/") & "abc.xls" xlWorkBook_new = exlapp.Workbooks.Open(strOriginal)
The code hangs in the last line. It works fine in the development environment. i deployed in windows server 2000 ,where I get this issue. the browser goes half way and throws the below exception after some time
[Code]...
I have set the identity impersonate to true in web config. This should be mostly an access rights issue.I have even provided access rights for the "everyone " user in the excel file and as well for the interop component. Please post ur valuable comments.
I'm trying to create a pivot table by opening an Excel file from my drive.But I'm receiving the error saying "Object reference not set to an instance of an object".[code]
I was wondering if there is a way to take an object in Visual Basic 2010 (Express, FWIW) and browse through its structure to visualize how the data inside is laid out.For example, I have an object called "model" that is populated by a function that is a black box to me. Model is set by a "read" function that loads a DXF file from disk. The read function isn't very well-documented.
What I've discovered is that model.Entities ends up containing a list of different objects, all with different properties. I'd like to be able to simply browse this list of objects and view their associated properties and values at run-time, similar to how you can use Intellisense to view a list simply by typing "blah." and waiting for the pop-up to appear.A tree view that you can pop open and closed would be excellent. Obviously this has to work during run-time rather than in the editor because the file hasn't been loaded if the program isn't running.
Is this something that's possible in Visual Basic 2010? Is it a built-in feature I can't find?
I am trying to figure out how to add my own properties to an object. i am trying to make my own rpg game and i want to be able to refer to a integer property like so: strengthstat = bronzelongsword.attackstrength. of course strength stat being an integer vairable that would equal to the property attackstrength that belongs to the bronze longsword.
In VB.NET I would like to create a complicated data structure with multiple types of data stored in an array like format (see below). I am trying to create a data structure that would look something like this: [Name; xLoc; yLoc; zLoc; [Jagged Array]] Note: Name needs to be dimensioned as a string, xLoc and so forth as integers. The Jagged Array would look like this:
I am constantly receiving back objects and it would be very useful be able to print out all of their properties. Is there a way in VB to get all the properties of an object and print them out (to console)?
I'm debuging an complex calculation object in my project, and I'd like to show its various and many properties in a textbox, to make my tests easier.
Can I do something like
for each p as someKindOfProperty in MyObject1 debug.print(p.name & " - " & debug.print p.value) textbox1.text = textbox1.text & vbcrlf & p.name & " - " & p.value next
I need to get all the object properties of a web browser. in this web page how do i retireve all the proeprties, like the text box name, html id, button name and so on.Also help me with retrieveing all the html ids of the browser. the html ids could be seen in the source page. but how do i get those ids.
