This example shows how to set variable value from code. First, load scripts:

@using Stimulsoft.Base
@using Stimulsoft.Report
@using Stimulsoft.Report.Blazor

Next, create buttons:

<div align="center">
    <input type="text" @bind="@NewValueInput" />
    <button class="alert" @onclick="@SetVariable">Set variable</button>
</div>

Then, add report viewer:

<div align="center">
    <StiBlazorViewer Report="@Report" />
</div>

After that, create empty report object and load report template:

@code
{
    private StiReport Report;
    private string NewValueInput;

    protected override void OnInitialized()
    {
        base.OnInitialized();

        //Create empty report object
        this.Report = new StiReport();

        //Load a report template
        this.Report.Load("Reports/ReportWithVariable.mrt");
    }

...

Then, create method to set variable:

...

	private void SetVariable()
    {
        //Get a copy of the report into a new report object
		var report = this.Reports.Clone() as StiReport;
		
		//Set new value
        report["MySuperUselessVariable"] = NewValueInput;

        //Render report with new value
        report.Render();
		
		//Assign new report to the viewer
		this.Report = report;
    }
}

In the screenshot below you can see the result of the sample code: