I have an array of 5 objects and also 5 textboxes. I am wanting to check to see if the values in the corresponding textbox are valid for the type of object.I have currently hard coded this, I parse out the object type and then use a tryparse statement depending on the object type.
Can I do this automatically? Can I detect the type and use a tryparse statement for that type. Maybe something like:if objectarray(x).tryparse(textbox(x).text, nothing)
Here is the structure that I have:
Friend Class StandardFormatFile
Friend fileType As String
Friend numberOfSeries As Integer
[code].....
I didn't think it fair to post a comment on Fredrik Mörk's answer in this 2 year old post, so I thought I'd just ask it as a new question instead..NB: This is not a critiscm of the answer in any way, I'm simply trying to understand this all before delving into memory management / the marshal class.
In that answer, the function GetByteArray allocates memory to each object within the given array, within a loop.Would the GetByteArray function on the aforementioned post have benefited at all from allocating memory for the total size of the provided array:
Dim arrayBufferPtr = Marshal.AllocHGlobal(Marshal.SizeOf(<arrayElement>) * <array>.Count)
I just wonder if allocating the memory, as shown in the answer, causes any kind of fragmentation? Assuming there may be fragmentation, would there be much of an impact to be concerned with? Would allocating the memory in the way I've shown force you to call IntPtr.ToInt## to obtain pointer offsets from the overall allocation pointer, and therefore force you to check the underlying architecture to ensure the correct method is used*1 or is there a better way? (ToInt32/ToInt64 depending on x86/64?)
*1 I read elsewhere that calling the wrong IntPtr.ToInt## will cause overflow exceptions. What I mean by that statement is would I use:
Dim anOffsetPtr As New IntPtr(arrayBufferPtr.ToInt## + (loopIndex * <arrayElementSize>))
I've read through a few articles on the VB.Net Marshal class and memory allocation; listed below, but if you know fo any other good articles I'm all ears![URL]..
I am creating a dll with all the functions and subroutines that I use all the time and I decided to create a function that I can pass different types of array to so the function obviously (or not) would have an array of type object. Now I no you can pass any type into an object type but when I pass an integer array into an object array I get an error.
value of type '1-dimensional array of integer' cannot be converted to '1-dimensional array of object' because 'integer' is not a reference type.
Shared Function CompareArray(ByVal FirstArray() As Object, ByVal SecondArray() As Object, Optional ByRef ErrorMessage As String = "") As Boolean
Dim IntArrayOne() As Integer = {1,2,3,4,5} Dim IntArrayTwo() As Integer = {1,2,3,5,6} Dim IsSame As Boolean = False IsSame = CompareArray(IntArrayOne(), IntArrayTwo())
I am having some trouble creating an object array of different object types. Here is what I have so far:
Public Sub New()
Dim b1 As New Book("Book Title 1", "Gold Book Publisher", 1.0, "Bob Jones", "192DJDJD212", "01/02/10")
Dim b2 As New Book("Book Title 2", "Gold Book Publisher", 1.0, "Bob Jones", "192DJDJD212", "01/02/10")
Dim b3 As New Book("Book Title 3", "Gold Book Publisher", 1.0, "Bob Jones", "192DJDJD212", "01/02/10")
[code]....
If I define the array As Book (Public publicationArray(6) As Book) or Magazine (Public publicationArray(6) As Magazine) I am able to access the properties of that class but not both. I think I need to define a type for each array instance but not sure how to do this.
I have an interface that describes an specialized list in my application...
[Code]....
Is there a way to make an interface serializable, or am I going to have to convert each of my objects into a concrete class implementing the interface, and then return that class?
I am trying to check this app. and make sure only numbers are placed into the textbox, but my tryparse isn't working.
Private Sub btnConvertC_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConvertC.Click
Dim intTemp As Integer 'holds the text input
If Integer.TryParse(txtTemp.Text, intTemp) Then
[code].....
what's the difference between variable array and object array?
View 7 RepliesI have become accustomed to using TryParse for attempting to parse unknown types:
Dim b As Boolean
Dim qVal As Boolean = If(Boolean.TryParse(Request.QueryString("q").Trim(), b), b, False)
or
bool b;
bool qVal = (Boolean.TryParse(Request.QueryString("q").Trim(), out b) ? b : false;
So, just curious if someone knows a better way of doing this other than using a ternary operator.
public static class PrimitiveType
{
/// This function will return a parsed value of the generic type specified.
/// </summary>
[code]....
Just pass in the type you're expecting as the generic and provide a string value to be parsed and a default value in case the string is not parsable. If you provide a class instead of a primitive type it will throw new ArgumentException("Generic type must be a valid Value Type that has a Parse method.");
The adultcombobox & childcombobox have value from 1 to 10, and none.I try put it in Do Loop like the code below, but the total price not come up so well, so I think I am having problem with the Do Loop and the Payment method.One more thing, do I need to Tryparse the combobox and use the selectedIndex ?
[Code]...
I am in my programming class and we had a small program to make that would check to see if an value that was entered is a integer and convert it to a Roman numeral. I know how to properly do it by putting the TryParse into the If...Then statement. What I am trying to do is to not use an If...Then statement and go just by a Case Selection statement. If it is not possible then that is cool with me, I am just trying to think outside the box. Here is what i have done with it:
[code]....
When you do say "Case 1" it says it needs to be "Case CBool(1)." Using either "Case CBool(1)" or "Case 1 = 1" provides the same result .However the code shows no errors it doesn't do the conversion, it always displays the label's value as "I"
this is for homework but I have 90% of the project done, I just need to finish the data validation portion of the code. This is what I have for the calculate click event:
[Code]...
this is for homework but I have 90% of the project done, I just need to finish the data validation portion of the code.This is what I have for the calculate click event:
Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click
Dim intInputA As Integer
Dim intInputB As Integer
Dim intInputC As Integer
[code]....
My Problem: I am using the Try parse to validate weather the inputA(B)(C) is an integer or not, if it is an integer, i want it to move to the nested if and validate that it is a positive number, and show the error message in the label if it is not. If it is not a number at all i want it to show another message in the label. The problem that I am getting is that even if i put in a letter for the input it does not catch it and it continues on to the select case, which comes out 0.
My understanding of the Integer.TryParse() function was that it tried to parse an integer from the passed in string and if the parse failed the result integer would remain as it did before.
I have an integer with a default value of -1 which I would like to remain at -1 if the parse fails. However the Integer.TryParse() function on failing to parse is changing this default value to zero.
Dim defaultValue As Integer = -1
Dim parseSuccess As Boolean = Integer.TryParse("", defaultValue)
Debug.Print("defaultValue {0}", defaultValue)
Debug.Print("parseSuccess {0}", parseSuccess)
[Code]....
On all my assignments I am asked to make sure the data is valid - only numeric, no empty strings. And I keep wondering which is the best to use IsNumeric or TryParse. When I try both on coding they seem to do the same thing, and I don't seem to find my answer online. Any ideas of why to use one over the other.
View 3 RepliesI am creating a program that will convert Celsius to Fahrenheit and visa versa. The program must use a function to return the answer. I'm using a string function that will return either the temperature in Celsius or Fahrenheit or "Please enter a valid temperature" if anything but a number is entered. TryParse is used to check if the input is valid.
When using the TryParse method in the function I am trying to use a parameter to pass the variable that will store the converted data type value [Code] The line " If Double.TryParse(tempTextBox.Text, scale) Then " is supposed to check if the conversion is possible and if it is pass either F or C as a variable to the scale parameter. It seems to verify the conversion all right but it doesn't actually do the conversion. Why isn't doing the conversion? Both F and C remain 0. I can get it to work by using two more TryParse methods (one in each branch of the If else statement in the function), but I'd rather not do this.
With a Decimal, I use:
document.Air1 = CDec(IIf(Decimal.TryParse(Air1TextBox.Text, Nothing), Air1TextBox.Text, "0")) to fill the column with there is no value.
I would like to do something similar when the date is blank (preferably with NULL or just plain blank):
document.TestDate1 = CDate(IIf(Date.TryParse(TestDate1TextBox.Text, Nothing), TestDate1TextBox.Text, " - - ")) - of course, this throws an exception.
The table Data Type is date.
The last line in the code below throws the error. Is it because I haven't intialized the size of the byte array?
Public Class Form1
Private toSocket_IPP As Byte()
Public Sub New()
[code].....
I am working on a project and came to a junction. I have various data in a object array, myObj().
How can one convert Object Array to Byte Array
I dont know if i should be using Memory Stream, Buffer, etc.
Is there any way to use the TryParse method to check for letter text input?For example, a user needs to input a name in a text box. Is there anyway to check that input are all letters?
View 4 RepliesThis is my code in vb.net 2010:
Structure feature_s
Public feature() As Integer
End Structure
[CODE]............
I keep on getting a error "object not set to an instance of an object" i am puzzled by this since there are no errors until i run the program. I redim the array. the build is fine. the exception is handled. and the structures and "dims are all global"
The code performs correctly when the input is an integer, but when I enter a character, the result is as though I've entered an integer. Can you tell me what's wrong with my TryParse statement?
Private Sub btnCompare_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCompare.Click
' Declare Local Variables
[CODE]...
How would I code a TryParse to get the input from customer from a textbox named Strands and convert it to a number (this number will always be a whole complete number, cannot be 5.6 or 4 1/2 or whatever) then have that Strand number be muliplied by the selected item in my listbox1. This listbox has an access database bound to it with 2 columns Size and Area, the Size equals the Area and I set the Value to the Area column but set the Size to show up in the list box. and the Strands textbox has to muliply by the Size picked, but by the Area # not the Size #. And the results of that multiplication showing up in another textbox named total.
View 14 Replieslike every class in .net does Arrays also inherit Object?
View 1 RepliesI'm having problems regarding using arrays on object names. for example, i have a textbox named txtBox1.text and a array declared as a(2). I what to transfer the value of the textbox to the array using loop.[code]
View 2 RepliesI want to know the difference. I have given 2 lines code.
CODE:
Let me know difference between both datatype.
I created a class named person and interface IPerson and tried to call this class in VB6 form. the class structure is given below
[Code]...
My project I am working on is a product location system for a large supermarket. My current issue is that the map I am using to display the product location is assembled from rectangle objects which I will then change the colour of when required.The array storing the locations is dimensioned as LocationArray(x) Where x is equal to the max rows function used on a table in database. Stored information always proceeded with "loc_" and the location. All rectangles are named in accordance with this.
I wish to pull the field name stored in the array (which corresponds to the rectangle to change colour) and be able to change its colour. This is giving me issue as the straight forward command of "LocationArray(x).Color = #" doesnt work as an array does not inherit this property.
I'm writing a wrapper class to expose a subset of the functionality of a .NET FTP library edtftpne from Enterprise Distributed Technologies.
When you call the edtftp's GetFileInfos method you get an array of FTPFile objects returned. I'm able to iterate through these but I don't know how to pass them on as a new and different object array containing only Name and Size for each file. Here's the code I have. Sorry it's a little confusing because I have my own class named FTPFile and the .NET library I'm using also has a class named FTPFile. I'm using both of them here. I should probably change the name of my class just to avoid confusion:
Public Function GetFileList() As FTPFile() Implements IFTP.GetFileList
Dim ftpfiles() As EnterpriseDT.Net.Ftp.FTPFile
ftpfiles = fCon.GetFileInfos 'Fill object array
[Code]....
I'd just pass on the object array that I'm getting from the GetFileInfos method but COM clients won't have access to the class/object EnterpriseDT.Net.Ftp.FTPFile without me rewriting it, I'm assuming.
My Task Background :I have list of data items and have to calculate/aggregate details about each data item and populate that to SQLServer database.I can do 1 by 1 insert [Traditional method]But, the application needs to perform good.Is it possible to aggregate the data in a 2d array and dump into database @ once ?' Populate this and insert it to database.
Private data(100, 100) As Object
So, how to do that ?Also, is it possible to use dataset in some way ?
