DxListBox<TData, TValue>.SearchTextChanged Event

Fires when the search text changes.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.2.dll

NuGet Package: DevExpress.Blazor

Declaration

[Parameter]
public EventCallback<string> SearchTextChanged { get; set; }

Parameters

Type	Description
String	A new value of the SearchText property.

Remarks

The SearchTextChanged event fires each time the SearchText property value changes.

The following code snippet implements an external search box for the List Box and handles search text changes.

Razor

<DxTextBox NullText="Type search text..."
           InputDelay="500"
           @bind-Text="@SearchText"
           SearchTextChanged="OnSearchTextChanged"
           BindValueMode="BindValueMode.OnInput"
           ClearButtonDisplayMode="DataEditorClearButtonDisplayMode.Auto">
</DxTextBox>
<br />
<text>The current search text is: @SearchText</text>

<DxListBox TData=Person TValue=Person Data="Staff.DataSource"
           ShowCheckboxes="true"
           SearchText="@SearchText"
           SearchTextChanged="OnSearchTextChanged"
           SelectionMode="@ListBoxSelectionMode.Multiple">
    <Columns>
        <DxListEditorColumn FieldName="FirstName"></DxListEditorColumn>
        <DxListEditorColumn FieldName="LastName"></DxListEditorColumn>
        <DxListEditorColumn FieldName="Department"></DxListEditorColumn>
    </Columns>
</DxListBox>

@code {
    public string SearchText { get; set; }
    void OnSearchTextChanged(string newSearchText) {
        SearchText = newSearchText;
    }
}

StaffData

namespace StaffData {
    public static class Staff {
        private static readonly Lazy<List<Person>> dataSource = new Lazy<List<Person>>(() => {
            var dataSource = new List<Person>() {
                new Person() { Id= 0 , FirstName="John", LastName="Heart", Department=Department.Electronics },
                new Person() { Id= 1 , FirstName="Samantha", LastName="Bright", Department=Department.Motors },
                new Person() { Id= 2 , FirstName="Arthur", LastName="Miller", Department=Department.Software },
                new Person() { Id= 3 , FirstName="Robert", LastName="Reagan", Department=Department.Electronics },
                new Person() { Id= 4 , FirstName="Greta", LastName="Sims", Department=Department.Motors },
                new Person() { Id= 5 , FirstName="Brett", LastName="Wade", Department=Department.Software },
                new Person() { Id= 6 , FirstName="Sandra", LastName="Johnson", Department=Department.Electronics },
                new Person() { Id= 7 , FirstName="Edward", LastName="Holmes", Department=Department.Motors },
                new Person() { Id= 8 , FirstName="Barbara", LastName="Banks", Department=Department.Software },
                new Person() { Id= 9 , FirstName="Kevin", LastName="Carter", Department=Department.Electronics },
                new Person() { Id= 10, FirstName="Cynthia", LastName="Stanwick", Department=Department.Motors },
                new Person() { Id= 11, FirstName="Sam", LastName="Hill", Department=Department.Electronics }};
            return dataSource;
        });
        public static List<Person> DataSource { get { return dataSource.Value; } }
    }

    public class Person {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public Department Department { get; set; }
        public string Text => $"{FirstName} {LastName} ({Department} Dept.)";
        public override bool Equals(object obj) {
            if (obj is Person typedObj) {
                return (this.Id == typedObj.Id) && (this.FirstName == typedObj.FirstName) && (this.LastName == typedObj.LastName)
                && (this.Department == typedObj.Department);
            }
            return base.Equals(obj);
        }
    }

    public enum Department { Motors, Electronics, Software }
}

The SearchTextChanged event is handled automatically when you use two-way data binding for the SearchText property (@bind-SearchText). The following code uses two-way data binding (@bind-SearchText).

Razor

<DxTextBox NullText="Type search text..."
           InputDelay="500"
           @bind-Text="@SearchText"
           BindValueMode="BindValueMode.OnInput"
           ClearButtonDisplayMode="DataEditorClearButtonDisplayMode.Auto">
</DxTextBox>
<br />
<DxListBox TData=Person TValue=Person Data="Staff.DataSource"
            ShowCheckboxes="true"
            @bind-SearchText="@SearchText"
            SelectionMode="@ListBoxSelectionMode.Multiple">
    <Columns>
        <DxListEditorColumn FieldName="FirstName"></DxListEditorColumn>
        <DxListEditorColumn FieldName="LastName"></DxListEditorColumn>
        <DxListEditorColumn FieldName="Department"></DxListEditorColumn>
    </Columns>
</DxListBox>

@code{
    public string SearchText { get; set; }
}

StaffData

namespace StaffData {
    public static class Staff {
        private static readonly Lazy<List<Person>> dataSource = new Lazy<List<Person>>(() => {
            var dataSource = new List<Person>() {
                new Person() { Id= 0 , FirstName="John", LastName="Heart", Department=Department.Electronics },
                new Person() { Id= 1 , FirstName="Samantha", LastName="Bright", Department=Department.Motors },
                new Person() { Id= 2 , FirstName="Arthur", LastName="Miller", Department=Department.Software },
                new Person() { Id= 3 , FirstName="Robert", LastName="Reagan", Department=Department.Electronics },
                new Person() { Id= 4 , FirstName="Greta", LastName="Sims", Department=Department.Motors },
                new Person() { Id= 5 , FirstName="Brett", LastName="Wade", Department=Department.Software },
                new Person() { Id= 6 , FirstName="Sandra", LastName="Johnson", Department=Department.Electronics },
                new Person() { Id= 7 , FirstName="Edward", LastName="Holmes", Department=Department.Motors },
                new Person() { Id= 8 , FirstName="Barbara", LastName="Banks", Department=Department.Software },
                new Person() { Id= 9 , FirstName="Kevin", LastName="Carter", Department=Department.Electronics },
                new Person() { Id= 10, FirstName="Cynthia", LastName="Stanwick", Department=Department.Motors },
                new Person() { Id= 11, FirstName="Sam", LastName="Hill", Department=Department.Electronics }};
            return dataSource;
        });
        public static List<Person> DataSource { get { return dataSource.Value; } }
    }

    public class Person {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public Department Department { get; set; }
        public string Text => $"{FirstName} {LastName} ({Department} Dept.)";
        public override bool Equals(object obj) {
            if (obj is Person typedObj) {
                return (this.Id == typedObj.Id) && (this.FirstName == typedObj.FirstName) && (this.LastName == typedObj.LastName)
                && (this.Department == typedObj.Department);
            }
            return base.Equals(obj);
        }
    }

    public enum Department { Motors, Electronics, Software }
}