> ## Documentation Index
> Fetch the complete documentation index at: https://ancplua.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# AL0020 - IFormCollection requires explicit attribute

> IFormCollection parameters must have an explicit [FromForm] attribute

Source: [AL0020ToAL0024FormBindingAnalyzer.cs](https://github.com/ANcpLua/ANcpLua.Analyzers/blob/main/src/ANcpLua.Analyzers/Analyzers/AL0020ToAL0024FormBindingAnalyzer.cs)

## Description

IFormCollection parameters must have an explicit \[FromForm] attribute. Unlike IFormFile which auto-binds, IFormCollection requires explicit attribution for clarity and safety.

## Bad Code

```csharp theme={null}
app.MapPost("/", (IFormCollection form) => ...);
```

## Good Code

```csharp theme={null}
app.MapPost("/", ([FromForm] IFormCollection form) => ...);
```

## Properties

* **Category**: ASP.NET Core
* **Severity**: Error
* **Enabled by default**: True
* **Code fix available**: False

## Configuration

```editorconfig theme={null}
dotnet_diagnostic.AL0020.severity = warning
```