c#


BindingSource.Find Multiple Columns


Is it possible to use the Find method of a BindingSource on multiple columns?
For example, say I have a gridview displaying current pets; two comboboxes, cboPetType and cboGender; and a button to create a new record into the Pet table based on the values of these two comboboxes.
Now, let's say I only want one of each PetType/Gender combination (Dog - M, Cat - F, etc.). So, if I have a Dog - M pet in my BindingSource and a user selects Dog and M from the comboboxes, I would like to stop the user to inform them that combination already exists.
In the past, I have used the BindingSource.Find method to do something similar, but, as far as I can tell, that is only good for searching one column (i.e. BindingSource.Find("PetType", cboPetType.SelectedValue);).
Is it possible to search a bindingsource based on multiple columns? If not, any suggestions to achieve my desired result? Any advice is greatly appreciated!
No, unfortunately this isn't possible. While it's likely that given a particular data source that such a search would be fairly simple, doing it in a more generic way (as the BindingSource would) is a little less transparent. For one, the syntax would be less than obvious. Here's a somewhat contrived solution:
public class Key
{
public string PropertyName {get; set;}
public object Value {get; set;}
}
public static int Find(this BindingSource source, params Key[] keys)
{
PropertyDescriptor[] properties = new PropertyDescriptor[keys.Length];
ITypedList typedList = source as ITypedList;
if(source.Count <= 0) return -1;
PropertyDescriptorCollection props;
if(typedList != null) // obtain the PropertyDescriptors from the list
{
props = typedList.GetItemProperties(null);
}
else // use the TypeDescriptor on the first element of the list
{
props = TypeDescriptor.GetProperties(source[0]);
}
for(int i = 0; i < keys.Length; i++)
{
properties[i] = props.Find(keys[i].PropertyName, true, true); // will throw if the property isn't found
}
for(int i = 0; i < source.Count; i++)
{
object row = source[i];
bool match = true;
for(int p = 0; p < keys.Count; p++)
{
if(properties[p].GetValue(row) != keys[p].Value))
{
match = false;
break;
}
}
if(match) return i;
}
return -1;
}
You can call it like this:
BindingSource source = // your BindingSource, obviously
int index = source.Find(
new Key { PropertyName = "PetType", Value = "Dog" },
new Key { PropertyName = "Gender", Value = "M" });
Bear in mind that for this to be usable, you really need a smarter comparison algorithm, but I'll leave that as an exercise to the reader. Checking for an implementation of IComparable would be a good start. Nonetheless, the concept should carry through regardless of that particular point of implementation.
Note that this won't take advantage of any of the possible performance optimizations that might be implemented by the underlying data source, whereas the single column Find would.
Another simpler solution, in case someone runs into the same issue. This works when the BindingSource is a DataView:
MyBindingSource.Sort = "Column1,Column2"
Dim underlyingView As DataView = DirectCast(MyBindingSource.List, DataView)
Dim searchVals As New List(Of Object)
searchVals.Add("SearchString1")
searchVals.Add("SearchString2")
Dim ListIndex as Integer = underlyingView.Find(searchVals.ToArray)
If ListIndex >=0 Then
MyBindingList.Position = ListIndex
Else
'No matches, so what you need to do...
End If
This is my version based on the above examples. It works very well.
Public Class clsBSHelpers
Public Structure Key
Public PropertyName As String
Public Value As Object
Sub New(ByVal pPropertyName As String, ByVal pValue As Object)
PropertyName = pPropertyName
Value = pValue
End Sub
End Structure
Public Shared Function Find(ByVal Source As BindingSource, ByVal ParamArray keys As Key()) As Boolean
Dim sb As New Text.StringBuilder
For i As Integer = 0 To keys.Length - 1
If sb.Length > 0 Then
sb.Append(",")
End If
sb.Append(keys(i).PropertyName)
Next
Source.Sort = sb.ToString
Dim underlyingView As DataView = DirectCast(Source.List, DataView)
Dim searchVals As New List(Of Object)
For i As Integer = 0 To keys.Length - 1
searchVals.Add(keys(i).Value)
Next
Dim ListIndex As Integer = underlyingView.Find(searchVals.ToArray)
If ListIndex >= 0 Then
Source.Position = ListIndex
Find = True
Else
Find = False
'No matches, so what you need to do...
End If
Return Find
End Function
End Class
I call it thus:
e.Cancel = clsBSHelpers.Find(CastingBedBindingSource, _
New clsBSHelpers.Key("PlantID", m_PlantID), _
New clsBSHelpers.Key("LineBedNUmber", m_LineBedNumber))
Hope this helps those that like it simple.
The more simple solution is by using Extension Method:
var id1 = "id1";
var id2 = "id2";
var data = bindingSource1.Cast<DataModelType>().Single(r => r.ID1 == id1 && r.ID2 == id2);
bindingSource1.Position = bindingSource1.IndexOf(data);

Related Links

Get by Reflection Properties from a Class
MSBuild log file location
Function not working in Form Load, but works everywhere else
C# Interaction.inputbox 2 inputs
c# DataGridView update cell value
XDocument descendants is throwing a null reference
String combination does not work [closed]
Calculator in C# input from keyboard using “&” in text property
Difficulty starting computing project
asp.net mvc c# listing categories recursively
GroupPrincipal.GetMembers vs LDAP search to get all users from Ad Group including sub group
C# Regular Expression throws Unterminated [] set
WPF ToggleButton Binding Not Working
C# - I get the following error when I add a number while running my program 'System.ArgumentOutOfRangeException' occurred in mscorlib.dll" [duplicate]
Security test for AES
“System.InvalidOperationException: Permission denied to access property” when using Selenium with Firefox

Categories

HOME
drupal
internet-explorer
grizzly
azure-eventhub
data-modeling
spss
arguments
redhawksdr
flowtype
meson-build
browserstack
osx-yosemite
restheart
google-my-business-api
runtime
activejdbc
decoding
yui
openstack-horizon
glibc
bootstrap-datetimepicker
vala
klipfolio
matlab-gui
procedural-generation
symlink
folder
edirectory
arp
foxpro
lines
choco
contextmenustrip
storefront
cache-control
campaign-monitor
lighting
anypoint-studio
mapquest
const
libconfig
armadillo
glide-image-library
compiler-warnings
smooth-streaming
jsfl
riemann
spring-cloud-aws
sqlproj
hdr
xcode7.1
weblogic-maven-plugin
nsoperationqueue
firefox-os
instabug
clear
gitk
avrcp
playn
web-standards
radgrid
aiff
unityvs
xmlserializer
cocos2d-x-2.x
redmine-plugins
isl
pthreads-win32
node-mongodb-native
kernel-density
android-jack-and-jill
raddatepicker
pyxplot
bho
magicsuggest
pageload
antixsslibrary
nsregularexpression
hypertable
google-email-audit-api
dancer
reflexil
pinchzoom
meego-harmattan
html-help-workshop
cstring
cons

Resources

Mobile Apps Dev
Database Users
javascript
java
csharp
php
android
MS Developer
developer works
python
ios
c
html
jquery
RDBMS discuss
Cloud Virtualization
Database Dev&Adm
javascript
java
csharp
php
python
android
jquery
ruby
ios
html
Mobile App
Mobile App
Mobile App