A Blazor component to create panes separated by a slidable splitter bar.
Note
I know the same feature component library, the "BlazorSliders", already exists, but it was a bit unsmooth, particularly on Blazor Server apps. So I've decided to create another one on my hand.
- Add package to your project like this.
dotnet add package Toolbelt.Blazor.SplitContainer
- Open
Toolbelt.Blazor.Splitter
namespace in_Imports.razor
file.
@* This is "_Imports.razor" *@
...
@using Toolbelt.Blazor.Splitter
- Then you can use the
SplitContainer
component in your Blazor app.
<SplitContainer @bind-FirstPaneSize="_PaneSize">
<FirstPane>
<h1>Hello</h1>
</FirstPane>
<SecondPane>
<h1>World</h1>
</SecondPane>
</SplitContainer>
@code {
private int _PnaeSize = 80;
}
Parameter Name | Type | Description |
---|---|---|
Id | string? | Gets or sets an id string applied for the "id" attribute of the split container element. |
Style | string? | Gets or sets a CSS style string applied for the "style" attribute of the split container element. |
Class | string? | Gets or sets a CSS class string applied for the "class" attribute of the split container element. |
FirstPane | RenderFragment | The left or top pane in the SplitContainer. |
SecondPane | RenderFragment | The right or bottom pane in the SplitContainer. |
Orientation | SplitterOrientation | Determines if the spliter is vertical or horizontal. The default value is SplitterOrientation.Vertical . |
FirstPaneSize | int? | Determines pixel distance of the splitter from the left or top edge. |
FirstPaneMinSize | int? | Determines the minimum distance of pixels of the splitter from the left or the top edge of first pane. |
SecondPaneSize | int? | Determines pixel distance of the splitter from the right or bottom edge. |
SecondPaneMinSize | int? | Determines the minimum distance of pixels of the splitter from the right or the bottom edge of second pane. |
FirstPaneSizeChanged | EventCallback | A callback that will be invoked when the size of the first pane is changed. |
SecondPaneSizeChanged | EventCallback | A callback that will be invoked when the size of the second pane is changed. |
Warning
You can specify the pane size to only either theFirstPaneSize
or theSecondPaneSize
parameter. If you specify both theFirstPaneSize
or theSecondPaneSize
parameters, then the splitter won't work.
The Orientation
parameter represents the "Splitter Bar" orientation that splits the SplitContainer
's client area into two panes. The following figures show the layout you will see with each SplitterOrientation
enum value set to the Orientation
parameter.
Vertical | Horizontal |
---|---|
![]() |
![]() |
When you set the FirstPaneSize
parameter, the first pane will be fixed size, and the second pane will be stretched to fill the remaining area of the SplitContainer
.
On the other hand, when you set the SecondPaneSize
parameter, the first pane will be stretched to fill the remaining area of the SplitContainer
, and the second pane will be fixed size.
I strongly recommend binding a pane size parameter to a field variable, like the following example.
<SplitContainer @bind-FirstPaneSize="_PaneSize">
...
</SplitContainer>
@code {
private int _PnaeSize = 80;
}
When you set a pane size parameter with a literal value, like below,
<SplitContainer FirstPaneSize="80">
...
</SplitContainer>
the pane size might be reset unintendedly to that literal value you specified even after a user has operated to resize the pane.
Please refer to the following example if you want to save and restore the pane size. The following example shows you how to save and restore the pane size into a web browser's local storage (The example uses the Blazored.LocalStorage
NuGet package to access the web browser's local storage API).
@inject ILocalStorageService LocalStorage
<SplitContainer @bind-FirstPaneSize="_PaneSize"
@bind-FirstPaneSize:after="OnPaneSizeChanged">
...
</SplitContainer>
@code {
private int _PnaeSize = 80;
protected override async Task OnAfterRenderAsync(bool firstRender)
{
if (firstRender)
{
var paneSizeStr = await this.LocalStorage.GetItemAsStringAsync("_PaneSize");
if (int.TryParse(paneSizeStr, out var paneSize)) this._PaneSize = paneSize;
this.StateHasChanged();
}
}
private async Task OnPaneSizeChanged()
{
await this.LocalStorage.SetItemAsStringAsync("_PaneSize", _PaneSize.ToString());
}
}
The size of the splitter bar is defined by the CSS custom property named --splitter-bar-size
scoped in the split-container
CSS class (The default value is '4px'). So you can change the size of the splitter bar by overriding that CSS custom property value like the following example.
::deep .split-container {
--splitter-bar-size: 14px;
}