How To Use BindingSource.Find Method Alongwith .Net Object Class
Mar 7, 2011
I want to search particular item in Binding Source for which i use BindingSource.Find() method, but it throws an exception "This operation requires an IBindingList". My binding source is bind to a .net class object.. I searched over the internet, but could not find the clear solution to achieve this task. The sample class code is given below:
Imports System.ComponentModel
Public Class Department
Private _code As Long
I'm binding a DataGridView to a BindingSource to a LINQ IEnumerable, I found that the BindingSource.Find method throws an exception because .Find isn't implemented in IEnumerable (and the BindingSource just passes the call to it's DataSource). I need to use BindingSource.Find to select/highlight a particular row in the DataGridView.
Is there a feasable way to extend my DataContext to support this behavior w/o breaking anything else? I expected to find the code out there already, but I've searched exaustively with no luck.Without it, I cannot "move" the BindingSource using .Position and that's a pretty common use of the BindingSource I think.
Basically, I've got this plugin-based application I've used all the time in VS2008 flawlessly. In my current project (VS2010 by the way) I wrote a plugin for the application and whenever I try to use an instance of a particular class (in an external dll) from my plugin, I get an error.
I tried watching the instance and I got the message: "Cannot find the method on the object instance." in the watch window. This has never happened before! I also found that some of the extension methods in the plugin does not work.
I'm trying to code a class of RandomNumber. One of the class methods needs to populate a "List (Of RandomNumber)" ... which was passed as a parameter to the method ... with 10 random numbers between 1 and 50. DEAD SIMPLE :)
As i described below code i am trying to find the the similar class from the ClassArray using the indexof method. How can we invoke name property inside the indexof method
Public Class Form1 Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
I have tried several versions of this with no luck. The casting of the worksheet works as my data is entered in other parts, but I have a section where I need to add data 1 column right of the cell containing the 'str(0)' value. Most of these parameters are optional. I have even tried the System.Reflection.Missing object.
I hate to see the name of the class used as a string parameter like "FileDownloader" in the code, and I would like to use something like this FileDownloader.Name(), where FileDownloader is name of the class.Only problem is that I can't find out how to do that without instantiating object or creating a static method..Is there a way to get a class name in .net without having the object instance and without creating a static method that returns the name of the class?
Consider a MyForm class that contains a shadowed implementation of Show(). It also contains a CreateForm() method, which accepts an instance of the form and calls the shadowed sub:
I am getting some wierd errors when using the ReportViewer control in Visual Studio 2008. When I try to access the LocalReport property, it displays with this error: "Cannot find the method on the object instance.". Also, I am getting invalid cast errors saying I cannot cast from Microsoft.Reporting.Winforms.ReportViewer to Microsoft.Reporting.Winforms.ReportViewer. I am getting this using either CType or DirectCast. This is really frustrating as I can find almost no documentation on this error.
I'm trying to use the bindingsource.find method to match a datarow column with a user entered text. I know that using BindingSource1.find("columnName", searchString) will work when the user enters the exact string. What I would like to know is how to find a row that is close to the string using a wildcard search... a good example I guess is:dim searchString as string = textbox1.text 'lets say the user enter "se"dim index as integer = myBindingSource.find("columnName", searchString) 'I would like to find the firs record that starts with "se"I can achieve the idea using the bindingsource.filter method but this will interfere with other parts of my application if the bindingsource is changed.
In my application, I have a single table. Two of the fields in the table are COUNTY and CATNUM. Both are string.
I want to perform a FIND on both fields. I have no problem doing the search on CATNUM alone IF I set a FILTER first. Due to the size of the table, it takes a few seconds to set the filter. Once the filter is set, .FIND works quickly.
The customer has the option of setting a filter to work on one COUNTRY at a time. If they choose to do so, no problem.
If they don't have a filter set and they are using the entire table, then when the customer wants to search for a COUNTRY & CATNUM, I present a list of COUNTRIES in the table and a textbox for them to input the CATNUM.
Now I have the COUNRTY and CATNUM - how do I do the FIND? I already know that I can FILTER the table by COUNTRY then do the find but as I said before, it takes too long for the filter to be set (in my mind anyway!).
I have a bindingsource that is connected to a table where tho fields determine uniqueness. During a refresh I would like to return to the row that the user was on when he clicked the refresh button. BindingSource.find only supports one column in so far as i have been able to infer. So how doi do it. Altering the table is out of the question. Besides searching on multiple fields is a common event. Like for example first and lastname or perhaps company and journal number.
i am trying to locate the id of a field using the binding source, if i type the full id, it is locating it successfully no problem, but that is not what i want, i want to type 3 digits of the end of the id and be able to still locate that record. i triedusing wildcards with it "%" with no success any suggestions?
Private Sub btnRPSearch_Click(sender As System.Object, e As System.EventArgs) Handles btnRPSearch.Click Dim currentRecord As String = RprAuthNumTextBox.Text
I want to search my db for the value abcd, so I wrote this Private Sub Button1_Click_2(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click MessageBox.Show(Me.Table_0BindingSource.Find("Hash", "abcd")) End Sub
but I keep getting -1 even if there is no data that matches what I want to search.
I've got a databound query in my application which is querying the "Customers" table in our database.I've created this directly from the ComboBox's datasource creator in the Design view.Various bits of code created in the designer include:
What I've done in the first stage of developing this feature is to show my users a ComboBox showing a specific subset of the customer list by applying a filter to the BindingSource.
What I want to do on a second pass is to allow the users to type a specific bit of information into a textbox and check whether it appears in Me.CustomerDataSet like so:
Dim x As IEnumerable(Of CustomerDataSet.customerRow) = From cust In Me.CustomerDataSet.customer Where cust.custno.Trim = "test" If x.Count <> 0 Then
At this point, I have a customerRow object. I want to check whether this customerRow object appears in the list presented to users in Me.ComboBox_Customers via the filtered Me.CustomerBindingSource. Me.CustomerBindingSource does not (directly) contain customerRow objects, it contains Object objects.How do I find out whether Me.CustomerBindingSource contains the customerRow object at whatever lower level?Also Once I've determined that Me.CustomerBindingSource contains the item, how do I select that entry in the ComboBox?
I have a custom business object called Customer and a Form1 with a BindingSource1, NumericUpDown1, TextBox1 and ComboBox1 and the attached code. Setting break points in the Property Sets shows that the Set for the ComboBox never fires at all even though the Set for the NumericUpDown and TextBox fire like crazy. [code]
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 have this class binded to a DataGridView with a BindingSource, what I'm trying to do is make the _SelectedMethod property a ComboBox in the GridView, and then make the items people are able to select from the ComboBox come from _Dictionary.here is my class which is binded to a DataGridView via a BindingSource.
Is BindingSource class makes use of Threading to read and write the values in controls and in objects?I mean how bindingsource know when properties of an object changes and sometimes seems not to know? Does it use a kind of BackGroundWorker running to watch changes on bindings objects? And why does it sometimes read and write properties so many times the same value on the same object's property?I found that it's sometimes easier not to use them since it's hard to know why a control do not update but, on the other hand, dealing with control events can be tedious. And what if i tried to make my own BindingSource Class not inherited from the System.Form.BindingSource
Basically I try to get a DataGridView and a BindingSource working inside a class. I define them by:
Dim TempDGV3 As DataGridView = New DataGridView Dim TestBinding As BindingSource = New BindingSource
When I manually add columns to the DataGridView, it works perfectly, but when I set it's DataSource to a bindingsource from a base class, it doesn't load data and keeps throwing 'object does not exist' errors. The bindingsource mentioned here did, however, work on other DataGridViews that are defined in the base class (and implemented in the form to which the base class belongs)
Same for the BindingSource(not the above mentioned, but the one I try to create inside the class in the beginning of this post). I try to use it in the following way:
But the BindingSource keeps returning 'Nothing' for it's datasource and basically doesn't work. However, the SourceDataGridView mentioned here gets filled with 63 columns with "AllowUserToAddRows" and other properties when the columns names are asked.
So my question is: how do I get the BindingSource and the DataGridView to work in this class? I'm getting the feeling I'm missing out on something very obviously here. If that's not the case, I can report back with more code?
I have a datagridview that is bound to a list object of a custom type via a BindingSource. From everything I've read, I should be able to click the column headers and the rows sort, This doesn't happen for me. Sortmode is set to automatic and the column headers aren't set to be used for selection so it should work.
I know that I could sort progamatticly but that seems a little bit of a waste given that I should just be able to do it by default.
I've been creating short test apps repeatedly to try to understand some of the concepts in VB.NET.For the most part it has been illuminating.I read Bucky's .NET knowlegebase tutorial on passing objects as parameters to newly created forms. He shows how to create a new class that inherits from the base form class and define a New() method with parameters Extending the concept I thought about doing the same thing with a form that was created at design-time (In this case Form2).
Base class has one field to hold numeric balance value. With 2 methods that accept arguments for adding and subtracting the new input calculating new balance. Sub class has four fields dates, transaction, memo and amount.I have a deposit form, and withdraw form. Each time one transaction is entered it creates an object with sub class fields, then adds to the account collection. My problem is not understanding how to call the deposit/withdraw method and pass the current transaction amount back to the base class to alculate the new balance. Does anyone have any links to information/tutorials on how to perform something like this? As you can see with my code I have tried various different approaches without any success.
Public Class airplane Private var_num_seats As Integer Private var_num_engines As Integer
[code]....
Obviously, I don't wish that the class Glider has the method "start_engines" neither the property "num_engines". Otherwise, other child classes may have. How can I supress these property and method in child class, not just ignoring (if I can)?
