How do I read static or local files in Blazor WebAssembly?

You can read static files by creating HttpClient Get calls. The GetStringAsync method sends a request to the specific URI and returns the response body as a string in an async operation. 

@inject HttpClient Http

@code {

    protected override async Task OnInitializedAsync()
    {
        var content = await Http.GetStringAsync(request Uri);

    }
}

If you can read local file, you will use ReadAsync() and  Encoding.UTF8.GetString() methods. Here is an example:

@page "/read localfile" 
<InputFile OnChange="@HandleFileSelection" /> 
<button @onclick="ReadFile">Read File</button> 
@if (!string.IsNullOrEmpty(fileContent)) 
{ 
    <div>@fileContent</div> 
} 

@code { 
    private IBrowserFile? file; 
    private string? fileContent; 
    private void HandleFileSelection(InputFileChangeEventArgs e) 
    { 
        file = e.File; 
    } 
    private async Task ReadFile() 
    { 
        if (file != null) 
        { 
            var stream = file.OpenReadStream(); 
            var buffer = new byte[file.Size]; 
            await stream.ReadAsync(buffer, 0, (int)file.Size); 
            fileContent = System.Text.Encoding.UTF8.GetString(buffer); 
        } 
    } 
} 

Note: The project mentioned above is designed for reading local text format documents. 

View Sample in GitHub