The code below shows me (I think) that the "for each" loop is about 10% faster than the "i to n" loop, but the "for each" loop creates 567k in new memory? Is this right? Which way is generally most efficient with regards to speed and memory usage? If you want to run this code in VB just add a button and 2 labels to a form.
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1) SortedLIst has a GetKey property: you ask for the nth key in the sorted list of keys and you get it. SortedList(of TKey, TValue) does not have this kind of feature. Why not?
2) SortedList stores values as "object." Is this a less memory-effective method to store values of Double than SortedList(of TKey, TValue)?
url...But what I'm looking for is just see if any alpha (0-254) is used in at least one of the pixels. Would the Bitmap.Lockbits and BitmapData method be the most efficient (speedy?) or is there another way. I've tried toying around with ColorPalette and the Alpha flag, but never could figure it out (and even if it is a way to check to see if the alpha channel is used at all).
View 5 RepliesI save the client data into an array list. How to find part of data(currentIP) inside the array list(clientList) with fast method? [code]
View 1 RepliesI need to find a method of looping through a listbox and retrieving the index number and values - quite straightforward in asp, but turning out to be something of a nightmare in winforms!Here is the scenario - The user can add values in a textbox, that are in turn added to a DataTable that gives it a unique ID and a row number, this is then bound to the listbox. The user can then move the items up or down the list by adjusting the row number in the datatable and rebinding to the listbox..
The problem that I am hitting is when the user needs to delete an item -the first part is easy - delete from the DataTable and rebind to the listbox. The bit where I hit the proverbial brick wall is needing to loop through the listbox rows and getting both the index number and the ValueMember - that way I can change the row numbers in the DataTable based on the index number against the ID number.
I was wondering what was the best way to search a database. Is it possible to perform bubble sort etc or any sort of binary search to the database instead of doing a linear search. If so how would I go about doing this through an Sql statement.
View 6 RepliesOk so I have this program that shows data in a treeview and that data is from a datatable.I'm basically looping through the datatable row by row and adding nodes.The data looks something like the following:
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I have a thread that is hitting the Database (where these records are stored) every 5 seconds to see if the list is smaller,bigger or changed.If so, I was just recalling the load_form sub but this was taking too long as the lists could potentially be very large. Also, there is a lot of logic that comes into play depending on what user is displaying the records in the treeview.I was wanting to know what would be the fastest way to compare the datatable that was previously used to initially create the nodes in the treeview to a tempdatatable that has the currently updated/added/removed rows and update the treeview accordingly?The only thing I could come up with was basically looping through the tempdatatable and comparing each row to the rows in the original datatable and plucking out the ones that had no match.Then recursively looping through the nodes in the treeview to find the spot that the new node should be added (based on that datarow's values).Or is there a better way to do this and I should scrap this?
Just wondering what the most efficient way to remove multiple characters that are next to each other is.so that running would become runing - notice letters can appear in there multiple times - the n in this case.[code]
View 1 RepliesI am looking for some guidance with the most optimal or efficient way to export a dataset to an excel file. I have searched the forums and found a number of methods to do this. However, the code I am currently using is very inefficient as it is itterating through the rows and columns to create the excel file. The app I am working on needs to be able to create 50 or so excel files each with 500+ rows and 40-50 columns. This method seems to inefficient for my use.
I have seen some code out there to use an ODBC call to excel to create the file. I am wondering if someone can verify that this is the most efficient way to meet my goal. It should also be noted that after the export I will want to do some basic formatting of the sheet. Adding bold column headers, autofilters, and autofit all columns.
How to get the key of a sorted list from the corresponding value directly without using For Each loop. For instance in the following code snippet, I want to get the key value (and not the index) of "Canada", how?
Code Snippet:
SortedList
Imports System
Imports System.Collections
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Here's a list example
SortedList name = test
"nothing" | 0
"something" | 1
How can I go about running a for each loop or something to add each first column in test to, say a listbox.
Listbox should just have listed.
nothing
something
I tried
For Each i In text.Values
lbTest.Items.Add(i)
Next
But that produces:
0
1
I have a the need for key value pair that I wish to sort so I decided to use a SortedList instead of a HashTable.I am adding the data in the order below to my SortedList which is the order I need it in
Key | Value
--------------------------------
1 "700-800" | List(Of Object)
2 "900-1000" | List(Of Object)
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The key is a string and the value is a List of objects. The key is representing a time slot that has been concatenated from two integer values and delimited by "-". "700" as a string was 0700 initially an integer.e.g.
Dim key As String = slotTimeStart.ToString() & "-" & slotTimeEnd.ToString()
But once these key value pairs are added to the SortedList they appear in the order
3 "1100-1200" | List(Of Object)
4 "1700-1800" | List(Of Object)
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Unfortunately I recieve the times slots as two integer values which cannot be changed.Is there any way to force a sort on a SortedList? or is this problem because of the way I am storing my key? Is there a better way to store it?
i can get a value, a key out of a list by using index ,key or value parameters but a kvp as object ?nattelip
View 13 Replieswhen you use the object browser to see the features of a sortedlist elementat is not shown , but because a sorted list inherets features of ienumerable it works, cant that be corrected
View 1 Repliesi have a sortedlist variable called :
Cart
which contains two Cartitem object and within these two objects is a further object called Product.i wish to amend the Product object Property named Quantity
["860"] = {Cartitem}
["861"] = {Cartitem}
When i attempt to update the Cartitem object using the key value it overwrites Cartitem to Product.
Present Update
Cart(key.ToString) = product
results in
["860"] = {Product}
How may i update a Product property without replacing Cartitem object to Product?
I'm making a sortedlist I can read a file into my program but do someone now how to show the output? Its made with classes and they will work. How to show the output of the file because I can't find.
This is the Form1
Public Class Form1
Public lijst As New SortedList(Of String, bankrekening)
'Dim spaar As spaarrekening
'Dim zicht As zichtrekening
Private Sub OverschrijvenToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OverschrijvenToolStripMenuItem.Click
FrmOverschrijven.show()
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I have a txt file I' m trying to read a line and add it to the array list, I' m identying the begining of the new line with B and N charecters in the 11 and 12 th positions respectively. Now the problem is that few keys are getting dropped the structure of the file is
10000BN test 1 test2
10000S0000 test3 test 4// these are getting dropped because they are on a new line
10000S 0000 test5
so how do I add these two lines to the record
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I have a SortedList
Protected _Items As New Generic.SortedList(Of String, _Control)
I am adding items into this SortedList
_Items.Add(_key, _Control)
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I have to provide an Excel file as an output. I have to color some of lines and make them bold.The input is based on a dynamic list (in memory) and it also could be based on CSV file that I'm already provide today (based on the same dynamic list).I'm wondering what would be the most efficient way (in terms of performance) in order to provide the colored Excel output?Should I export directly from dynamic list into Excel - or - Should I export from CSV into Excel ?
View 7 RepliesMine is a windows app. containing forms named BOM nd BOMSelected..There is datagridview in BOM which contains checkbox column.. When the user selects checkbox, the selected rows should be seen in the datagridview of other form, SelectedBom..
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I have been using the following code for quite some time to list the property values of an object:
Dim instance As New Configuration
Dim propValue As Object
For Each pi As System.Reflection.PropertyInfo In instance.GetType.GetProperties()
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Works great but we've gotten alot of properties at this point and could use them in alphabetical order.
looping through check boxes.. checkbox1, checkbox2, checkbox3...... Error in the code ocheck = "CheckBox" & Str(t) as "Run time errors may occur when converting 'string' to 'Microsoft.office.interop.word.checkbox'." Dim No_Checkboxes As Integer, ocheck As CheckBox
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I would like to know how to loop with textboxs. For example. I would set the text to "Hello" And the loop will send this...
-"Hello1"
-"Hello2"
-"Hello3"
I have tried many looping techniques but they all used listboxs and even modifying them I could not get it to work correctly.
I have this Visual Basic class I'm taking online. At this point in the section all I'm supposed to know about are Do, Do While, Do Until, Exit Do, Continue Do, and For Next loops. So try not to go off in a fancy super-coder direction. And everything is (preferably) made through Console Applications on VBE 2008
Problem 1:
Write a program that evaluates the factorials of the integers from 1 to 10 using an appropriate data type. (factorials are... factorial of 1 is 1, factorial of 5 is 120, or 1*2*3*4*5=120)
Problem 2:
Make a diamond - 1 asterisk at the top, 9 asterisks at it's widest - using only nested For...Next statements to print the asterisks AND spaces, minimizing use of output statements.
[code]I am facing difficulty in coding when intRow loop for the 2nd round. Error message "There is already an open DataReader associated with this Command which must be closed " appear in the above red highlight vb.net code.
View 6 RepliesI have some code that should update my listbox with files in a directory i have this code put in a timer:
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Have this Uni question; which after 20 minutes of frustration I'm sending it to the brain trust (you might be interested).Write a program that, when a button is pressed, checks the contents of a textbox. If the textbox does not contain a number, the program informs the user of this and does nothing more. Once a number has been entered, the program will do something trivial such as displaying double the number in a message box.Notice that this can be done without explicit looping,even though the user might repeatedly enter non-numbers. Because it is an event-driven program, each iteration is started when the user clicks the button. The looping is driven by the user, not by a looping statement.
View 5 RepliesIm trying to loop through all rows in a datagrid and enter a calculation in the field in the next column (first column is already populated with appliance names). The code below works but only on the first row. Can someone be good enough to point out my error? For Each row As DataGridViewRow In DataGridView1.Rows
If DataGridView1.Rows(s).Cells(0).Value = "" Then
DataGridView1.Rows(s).Cells(1).Value = "0"
Else
DataGridView1.Rows(s).Cells(1).Value = dtDLopt.Compute("SUM(Measurement)", "Appliance = '" & DataGridView1.Rows(s).Cells(0).Value & "'")
End If
Next row
I'm using this code to get the preview window
Dim iHeight As Integer = picCapture.Height
Dim iWidth As Integer = picCapture.Width
'
' Open Preview window in picturebox
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As you can see, I have 2 sources. Would it be possible to not show the preview window, but instead loop through all the sources?
That would be in a timer, so like each 10 seconds a pictures is made from each source.
i have a winform and i have about 30 labels and 30 picture boxes on it. What i would like to do is fill each label and picturebox with a value and image from a backend database. I could have easily done this in vb6 using control struture , for eg.
for x = 1 to 30
picturebox(x).image = value from database
label(x).caption = value from database
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