Yyds dry goods inventory it's not easy to say I love you | use the minimum web API to upload files

Preface

stay .NET 6 Before , The file upload function is very simple ：

Log in and copy

      
      

       
       [HttpPost("upload")]
       
       
public async Task<IActionResult> Upload(IFormFile file)
       
       
{
       
       
    // Yes file Perform the operation 
       
       

       
       
    return Ok(file.FileName);
       
       
}
      
      
      
      

       
       
1.
       
       
2.
       
       
3.
       
       
4.
       
       
5.
       
       
6.
       
       
7.
      
      

however , When using .NET 6 Minimum WEB API To achieve the same function , But unexpectedly encountered many pits .

Implementation code

Convert to minimum WEB API To realize , The code looks like this ：

Log in and copy

      
      

       
       app.MapPost("/upload", async (IFormFile file) =>
       
       
{
       
       
    return Results.Ok(file.FileName);
       
       
});
      
      
      
      

       
       
1.
       
       
2.
       
       
3.
       
       
4.
      
      

however , When called with the same client code , But back to HTTP 415 error :

allow Content Type

This is because when uploading files , The use of Content-Type Not by default ​​application/json​​​, It is ​​multipart/form-data​​

stay dotnet/aspnetcore Of issues in , We found a solution （https://github.com/dotnet/aspnetcore/issues/35082）：

Modify the code as follows ：

Log in and copy

      
      

       
       app.MapPost("/upload", async (IFormFile file) =>
       
       
{
       
       
    return Results.Ok(file.FileName);
       
       
}).Accepts<IFormFile>("multipart/form-data");
      
      
      
      

       
       
1.
       
       
2.
       
       
3.
       
       
4.
      
      

result , Or return to 415 error . What's more strange is that , There is an extra stack of error messages :

Surprise BUG

therefore , Want to find the problem by looking at the code .

Use error messages “Expected a supported JSON media type but got”, We located the source code file ​​Http/Http.Extensions/src/RequestDelegateFactory.cs​​:

however , Find out master Branches and v6.0.0 Branch code , Huge differences . such as ,master The branches are ​​IFormFile​​ Related codes , and v6.0.0 It's not at all ：

View the submission history of the file , We found such a submission ：

According to submission , We found the corresponding issue（https://github.com/dotnet/aspnetcore/issues/34303）：

#yyds Dry inventory #

It seems , If you want to support ​​IFormFile​​ Parameters , We have to wait until 2022 year 11 month （.NET 7 Expected release date ）！！！

Solution

fortunately , The issue It also provides flexible solutions , Pass in HttpRequest Parameters :

Log in and copy

      
      

       
       app.MapPost("/upload",
       
       
    async (HttpRequest request) =>
       
       
    {
       
       
        var form = await request.ReadFormAsync();
       
       

       
       
        return Results.Ok(form.Files.First().FileName);
       
       
    });
      
      
      
      

       
       
1.
       
       
2.
       
       
3.
       
       
4.
       
       
5.
       
       
6.
       
       
7.
      
      

Verify success .

Conclusion

Back , I've also tried in .NET 6 Use the previous Controller How to achieve , No problem at all .

It seems to be the smallest WEB API Are different implementation mechanisms , I'm not sure if there are any other pits .

Suggest ： Minimum WEB API Don't use it for production projects for the time being .

If you think this article has inspired you , Please pay attention to my official account ”My IO“