I have assigned a column of values from an Excel file into a dataset.I am using the following code to check if the column header is empty:[code] However for some reason even if I have an empty column header in the Excel spreadsheet, it is automatically assigned a value within the dataset. For example if I blank out the third column header in Excel spreadsheet, the dataset assigns it as "F3" as its column header which is making the above code ineffective. Can anyone tell me how to prevent the dataset to automatically assign a value to its column header.
im using a Dataset which loads XML from xml file on form startingit has one more form in which button click event adds a table to dataset but while adding it , compiler gives error like" DataSet loaded from XML , editing is not possible (like that)"
I created a program that has serval labels on a form and a listview object. It has a button that when clicked reads a textfile and loads up values in the listview object. I then can click and drag text from the listview box to any label on the form and then the program removes the value from the listview box. Now, my question is how can I instruct VB to save these values in the text property of the labels so that the next time the program is loaded the labels will contain the values loaded during the last run time session?
I have a multi-user app which consists of a Windows form (VS2008), and a SQL Express 2008 database. I'm already detecting if the dataset has changed before the user closes the form so I can prompt them to save their changes. What I'd like to do is to capture the changes they've made, and write them to a database table so that users can track all changes made to each record on the DB.What is the best way to grab hold of the data changes before they're written back to the DB and also grab the original records?
I have a need to assign values from my dataset to a variable but when i use string (which its normally text) and the item in that row of the dataset is empty it tells me that conversion from DBnull to string is not valid
I have two rich text boxes, and two buttons on my screen. The first button grabs HTML from a URL and then converts the HTML to XML which resides in rich text box 1.
The second button is to grab the XML from the rich text box1 and then parse it to grab all the input elements by their ID.
My issue is that my parser isn't doing anything. My guess is that I'm not quite getting the XML from the first rich text box.
What would be the best way to grab the XML from a rich text box load it into memory and then parse the XML to grab all the ID tags?
I have two rich text boxes, and two buttons on my screen. The first button grabs HTML from a URL and then converts the HTML to XML which resides in rich text box 1. The second button is to grab the XML from the rich text box1 and then parse it to grab all the input elements by their ID.
My issue is that my parser isn't doing anything. My guess is that I'm not quite getting the XML from the first rich text box.What would be the best way to grab the XML from a rich text box load it into memory and then parse the XML to grab all the ID tags?
So i have a DB with 3 tables. User Table with U_ID and U_Name, Class with C_ID, and C_Name and User_Class Table with U_ID and C_ID. Foreign keys are set.I want to display the classes associated with the selected user. The user is identified by their name. I know these are the two SQL statements I need to execute:SELECT U_ID FROM User WHERE U_Name = current_U_name
then SELECT C_ID FROM User_Class WHERE U_ID = current_U_ID then
I am using strongly typed dataset and have many tables in that. The problem is now I want to filter data from GetData() function which has a query like select * from table_name
How can I filter a particular table and distinct values from it. Also if I try to filter it return all column but rest have null values except the one I asked, so I cannot assign it as a datasource to a datagrid or combobox. How can I do this..
How to update combobox values coming from a dataset if I change the connection string. The connection string takes effect but doesn't update the dataset tied to the combobox.
I have visual studio 2008 I have two different datasets that take values as "money". those datasets are in two different forms. I would like to collect each and every value of all different entries o the two datasets, and add them so that I can display the totals in a new form that has textboxes that displays the total of the two different datasets.
I have a textbox which is bounded to the typed dataset. If the user in the textbox &hit keydown, it should allow only numeric values with 2 decimal points and also it should not allow more than one "."(dot). I found many but all thats are using textbox event
it's possibly to bind the values in a combobox to a column in a dataset? If so, how would I go about doing it? For example, If I have a column named 'Names' in a DataSet, each comboBox item would be a name from that column.(There will only me at maximum, 10 entries)
In a WinForms app (VS2008 / .Net Framework 3.5) I bind data from SQL Server to controls. If there's a null value e.g. an employee has no middle name (allowed by business rules), when I browse that record at runtime an exception is thrown. So I code: If Not (row("middle_name") Is DbNull.Value then txtMiddleName.DataBindings.Add(New Binding("Text", row, "middle_name)). Say someone adds a middle name to this record, because the control had no databindings the dataset.HasChanges property is false and update stored proc doesn't run. I guess I could handle this like this: If txtMiddleName.Databindings.Count = 0 AndAlso txtMiddleName.Text <> "" Then row("middle_name") = txtMiddleName.Text. I guess I would have to do something similar to handle a value changing from not null to null.
I'm working with a zedgraph bar chart and displaying only certain values from a dataset. I have a dataset with 912 records. One field is called "DeviceName" and one is called "TimesOffline". I am able to bind the chart to the dataset, but it wants to plot all 912 records. What I need is to somehow sort the dataset to retrieve the top 10% (or something) devices with the highest number of times offline.
Trying to make a vb.net program that is able to read values from an access database and pass them into some data sets. Here is the code I have so far, with the error line between the two dotted lines:
UPDATE OPENQUERY (db,'SELECT * FROM table WHERE ref = ''"+ Ref +"'' AND bookno = ''"+ Session("number") +"'' ') How would I prevent SQL Injections on this?
Is there a way to prevent the VB .NET editor from saving the project whenever IT LIKES TO ? It very annoying ; it so stupid that it saves things that I don't want to and that I didn't ask it to do .If I add a form and then close the editor , when I open the project again , that form is still there though I DIDN'T save it !If I change a declaration from Friend to Public and close the editor without saving , then when I open again the project , my modified code remains modified , though I DID NOT save it !Today I realized that if I delete some controls of a form and then close the Editor , then when I reopen it , the controls are missing for good ! It saved that modification by itself !
I've completed an assignment that requires me to search through two listboxes for a particular number.If the number is found, the text on a label changes to a dollar amount, otherwise a message box is displayed letting the user know that the requested number cannot be found.It works well enough, searches through the listboxes, finds the number, and displays the message box when it can't be found.However, the message box shows repeatedly up to five times.After the user clicks "OK" on the fifth appearance, the program crashed and displays the follow message."Invalid Argument = Value of '5' is not valid for 'index'.Parameter name: index."I don't know what's causing this, or how to fix it.I do use the index as a counter at a portion of the program...but I'm not sure where I went wrong with it.[code]Also there are five items in the second listbox...probably has something to do with it.
I designed an application in vb.net 2005 while using Administrator account on vista.After compiling the application it start requesting for elevation during startup.I will like to prevent this, because the customer is complaning
i have develop small project in vb.net and also created setup for it with license key but when i install the project in C drive it can run on another machine with simply copy it how to prevent this piracy
I have 2 forms. Form1 and Form2 When the user calls for a new record to be created, Form2 shows modally centered in form1. I have disabled the control box and need to stop the form from being moved by the mouse. I do not see (Movable) in the properties list.
I have a program, I have published it, and I have been actually using it in my PC. Whenever it encounters an error, the JIT debugger comes out. How do I prevent it from popping up using try...catch blocks, or is there any other ways or code on how to do this?
<VB.NET 2008>I created a MDI frame and I try to open a Winform by clicking menu.I do not want to allow opening same winform which is already opened by user.How do I check whether the winform is already opened or not?
