CODEWITHSUNDEEP
c#asp.netblazorblazor-server-side
Vischi
Vischi

Reputation: 229

Get all Files in a directory throws error - Cannot dynamically create an instance of type 'Photobx.Pages.Index'. No parameterless constructor defined

I want to do an "image gallery" in my Blazor Server App. For each Filepath it should create an <img src="@file"/> element containing the filepath in the local variable "file".

Now it throws me this error: MissingMethodException: Cannot dynamically create an instance of type 'Photobx.Pages.Index'. Reason: No parameterless constructor defined.

My files are in wwwroot/pics .

Here is my code:

index.razor

@foreach(string file in filepaths)
{
    <img src="@file"/>
}

@code {
    private IWebHostEnvironment Environment;
    public List<string> filepaths = new List<string>();

    public Index(IWebHostEnvironment _environment)
    {
        Environment = _environment;
    }

    public void GetFilePaths()
    {
        foreach(string file in Directory.GetFiles(Path.Combine(this.Environment.WebRootPath, "pics/")))
        {
            filepaths.Add(file);
            Console.WriteLine(file + " was added");
        }
    }

    protected override void OnParametersSet()
    {
        GetFilePaths();
    }
}

Upvotes: 1

Views: 583

Answers (1)

Dimitris Maragkos
Dimitris Maragkos

Reputation: 11392

You cannot inject parameters to a Blazor component from the constructor.

You can use the @inject razor directive

@inject IWebHostEnvironment Environment

@foreach(string file in filepaths)
{
    <img src="@file"/>
}
...

or [Inject] attribute when using code-behind approach.

public class ComponentBase : IComponent
{
    [Inject]
    protected IWebHostEnvironment Environment { get; set; }
}

Check microsoft documentation for more information regarding this topic.

Upvotes: 4

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