ComboBox DataSets Qty

[Guest]

My Program: a local C# ADO.Net application using VS 2003

Right now I have about 5 ComboBox's which provides drop down selection
entries from the same MS-Access table via a DataConnection, DataAdapter and
DataSet datasource. Each CB has it's own DA and DS. When I tried to use the
same DS as the datadource for each of the five CB's, changing one of the CB's
selection affectd the other four CB's.

New business requirements require I increase the number of CB's from 5 to
about 100. What do I do? Do I create 100 DA and DS?

Steve

 

[Bart Mermuys]

Hi,
inline

My Program: a local C# ADO.Net application using VS 2003

Right now I have about 5 ComboBox's which provides drop down selection
entries from the same MS-Access table via a DataConnection, DataAdapter
and
DataSet datasource. Each CB has it's own DA and DS. When I tried to use
the
same DS as the datadource for each of the five CB's, changing one of the
CB's
selection affectd the other four CB's.

Instead of using a different DataSource (DataSet) for each ComboBox, you can
use a different BindingContext :

comboBox1.BindingContext = new BindingContext();
comboBox1.DataSource = ds; // same datasource
comboBox1.DisplayMember = ....;

comboBox2 .BindingContext = new BindingContext();
comboBox2.DataSource = ds; // same datasource
comboBox2.DisplayMember = ....;

.....

This way the comboboxes will create different CurrencyManagers(which
mantains position) for the same datasource/datamember and allow independent
navigating.


HTH,
greetings

 

[Guest]

Bart

Thank You for responding. Great Idea. Will try it this weekend.

One question, the DataSource and DisplayMember assignments are in VS CB
properties window. Where do I put the comboBox1.BindingContext = new
BindingContext() statement so I get it in the order you specified or can I
put it anywhere (i.e. Constuctor, form Load() event)? Can I somehow get "new
BindingContext()" into the VS CB (DataBinding) block ?? Or do I remove the
CB DataSource and DisplayMemeber and put it all in my code after the
InitializeComponent();

Steve

 

[Bart Mermuys]

Hi,

Bart

Thank You for responding. Great Idea. Will try it this weekend.

One question, the DataSource and DisplayMember assignments are in VS CB
properties window. Where do I put the comboBox1.BindingContext = new
BindingContext() statement so I get it in the order you specified or can I
put it anywhere (i.e. Constuctor, form Load() event)? Can I somehow get
"new
BindingContext()" into the VS CB (DataBinding) block ?? Or do I remove
the
CB DataSource and DisplayMemeber and put it all in my code after the
InitializeComponent();

It doesn't matter where you bind, from code or with the properties window.
The new BindingContext assignments can only be done in in code. A good
place would be after InitializeComponent() in the constructor.

If you want independent navigating, sorting and filtering, you can:
Create a different dataview for each combox and bind that ( from code or
designer ) .

If you only want independent navigating you can gain some performance:
Create a single dataview (designer or code) and bind that to all ComboBoxes
and then give each ComboBox a new BindingContext from code.


HTH,
greetings

 

[Guest]

Bart,

Again thank you for the free input

Yes, I do want sorting of the comboBox dropdown but didn't know how to do it
Not real familar dataview but have used it once or twice - need to check it
out.

 

[Guest]

Bart

Hope your still there, It gets a little more differcult.

The db may already have a entry for that field that should be loaded as
ComboBox.text when the form opens. The user should also have a choice to
edit the field without changing the other 20 "charaCode" fields

From IntializeComponent() method:
this.charaCode1CB.DataBindings.Add(new System.Windows.Forms.Binding("Text",
this.csiDbDS, "Main.CharacteristicCodes1"));

Adding "charaCode1CB.BindingContext = new BindingContext();" seems to
remove that previous binding

Steve