On Demand Filtering

[Michael Murphy]

I am new to the WinForms components and here is what I would like to be able to do. Not sure if this functionality is built in or if I will need to use a combination of Telerik controls so I figured it would be faster to ask. :)

I want to be able to fill a listview... then have a way to type in criteria and have it filter the listview accordingly. I want to be able to use checkboxes so once I have the listview filtered I can select certain items using the checkboxes.

Then I want to be able to remove the criteria and the listview restores all the items while retaining the items with checks in the checkboxes. Then i'll enter new criteria, which filters the list, i select more items via the checkboxes, remove the criteria, selected items are retained and so on...

Please let me know how to do this. :)

[Ivan Todorov]

Hello Michael,

Thank you for your question.

Yes, this can be easily achieved using RadListView. It supports built-in checkboxes and filtering via filter descriptors. Below is a sample code that implements the mentioned requirements. It assumes using a RadListView and a RadTextBox.

public partial class Form30 : Form
{
    public Form30()
    {
        InitializeComponent();
        this.radListView1.ShowCheckBoxes = true;
    }

    private void radTextBox1_TextChanged(object sender, EventArgs e)
    {
        this.radListView1.FilterDescriptors.Clear();

        if (this.radTextBox1.Text.Length > 0)
        {
            this.radListView1.FilterDescriptors.Add(new FilterDescriptor("Value", FilterOperator.Contains, this.radTextBox1.Text));
            this.radListView1.EnableFiltering = true;
        }
        else
        {
            this.radListView1.EnableFiltering = false;
        }
    }
}

More information about RadListView can be found in its corresponding help section.

I hope this was useful. Do not hesitate to contact me if you need further assistance.

All the best,
Ivan Todorov
the Telerik team

[Michael Murphy]

AWESOME! Works perfectly! Thanks for saving me time!

[Ivan Todorov]

Hello Michael,

I am glad I could help.

Feel free to share with us your feedback on this new control or contact us whenever you need assistance. We are always ready to help you.

Best wishes,
Ivan Todorov
the Telerik team

[RR]

Hi,

What if I wan to use multiple filter criteria?

For Example: Lets say I have two List Views with ShowCheckBoxes set to True
.
ListView1 with items Type1, Type 2 Type 3
And  ListView2 with Items T11, T12, T13, T21,T22, T23, T31. T32,T33

When I Select Type1 in ListView1, then I need to Show the items T11, T12, T13  only in ListView2
Similerly when I select Type2 then T21,T22, T23 needs to be shown and same as the case for Type3

I'm able achieve this behavior by adding the Filter.

Now the it is required to show T11, T12, T13, T21,T22, T23  items When both Type1 and Type2 are selected.

I Tried to achieve this by adding multiple FilterDescriptors but of no use. 

Is this feature supported by ListView filtering? If yes, please explain me how to achieve.

Thanks.

[Ivan Todorov]

Hi RR,

You can use the CompositeFilterDescriptor to achieve this. The following code snippet demonstrates this:

private void radListView1_ItemCheckedChanged(object sender, Telerik.WinControls.UI.ListViewItemEventArgs e)
{
    CompositeFilterDescriptor des = new CompositeFilterDescriptor();
    des.LogicalOperator = FilterLogicalOperator.Or;

    if (this.radListView1.Items[0].CheckState == ToggleState.On)
    {
        des.FilterDescriptors.Add(new FilterDescriptor("Text", FilterOperator.StartsWith, "T1"));
    }
    if (this.radListView1.Items[1].CheckState == ToggleState.On)
    {
        des.FilterDescriptors.Add(new FilterDescriptor("Text", FilterOperator.StartsWith, "T2"));
    }
    if (this.radListView1.Items[2].CheckState == ToggleState.On)
    {
        des.FilterDescriptors.Add(new FilterDescriptor("Text", FilterOperator.StartsWith, "T3"));
    }

    this.radListView2.FilterDescriptors.Clear();
    this.radListView2.FilterDescriptors.Add(des);
}

Do not hesitate to contact us, if you have any additional questions.

Greetings,
Ivan Todorov
the Telerik team

[Jorge]

Hello,

And as it would be to implement a custom icons view?

filtering a radlabelelement within a stack added to radlistview in iconsview mode.

[Hristo]

Hello Jorge,

Thank you for writing.

I am not sure that I completely understand your question. Could you please provide me with details about your scenario and the type of functionality you are after?

Looking forward to hearing from you.

Regards,
Hristo Merdjanov
Telerik