表单键或值的长度限制超过2048 [英] Form key or value length limit 2048 exceeded

问题描述

我正在使用asp.net内核来构建API.我有一个允许用户使用此代码上传个人资料图片的请求

I am using asp.net core to build API. I have a request that allow user to upload profile image using this code

 [HttpPost("{company_id}/updateLogo")]
        public async Task<IActionResult> updateCompanyLogo(IFormFile imgfile,int company_id)
        {
            string imageName;
            // upload file
            if (imgfile == null || imgfile.Length == 0)
                imageName = "default-logo.jpg";
            else
            {
                imageName = Guid.NewGuid() + imgfile.FileName;
                var path = _hostingEnvironment.WebRootPath + $@"\Imgs\{imageName}";
                if (imgfile.ContentType.ToLower().Contains("image"))
                {
                    using (var fileStream = new FileStream(path, FileMode.Create))
                    {
                        await imgfile.CopyToAsync(fileStream);
                    }
                }
            }
.
.

，但始终返回此异常:Form key or value length limit 2048 exceeded
请求
http://i.imgur.com/25B0qkD.png

but it keeps returning this exception: Form key or value length limit 2048 exceeded
The Request
http://i.imgur.com/25B0qkD.png

更新:
我已经试过了这段代码，但是没用

Update:
I have tried this code but it doesn't work

    services.Configure<FormOptions>(options =>
    {
        options.ValueLengthLimit = int.MaxValue; //not recommended value
        options.MultipartBodyLengthLimit = long.MaxValue; //not recommended value
    });

推荐答案

默认情况下，ASP.NET Core在

By default, ASP.NET Core enforces key/value length limit of 2048 inside FormReader as constant and applied in FormOptions as shown below:

public class FormReader : IDisposable
{
    public const int DefaultValueCountLimit = 1024;
    public const int DefaultKeyLengthLimit = 1024 * 2; // 2048
    public const int DefaultValueLengthLimit = 1024 * 1024 * 4; // 4194304
    // other stuff
}

public class FormOptions
{
    // other stuff
    public int ValueCountLimit { get; set; } = DefaultValueCountLimit;
    public int KeyLengthLimit { get; set; } = FormReader.DefaultKeyLengthLimit;
    public int ValueLengthLimit { get; set; } = DefaultValueLengthLimit;
    // other stuff
}

因此，您可以使用KeyValueLimit和ValueCountLimit属性(也包括ValueLengthLimit等)来创建自定义属性，以明确地自行设置键/值长度限制:

Hence, you may create a custom attribute to explicitly set key/value length limit on your own by using KeyValueLimit and ValueCountLimit property (also ValueLengthLimit etc.):

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
public class RequestSizeLimitAttribute : Attribute, IAuthorizationFilter, IOrderedFilter
{
    private readonly FormOptions _formOptions;

    public RequestSizeLimitAttribute(int valueCountLimit)
    {
        _formOptions = new FormOptions()
        {
            // tip: you can use different arguments to set each properties instead of single argument
            KeyLengthLimit = valueCountLimit,
            ValueCountLimit = valueCountLimit,
            ValueLengthLimit = valueCountLimit

            // uncomment this line below if you want to set multipart body limit too
            // MultipartBodyLengthLimit = valueCountLimit
        };
    }

    public int Order { get; set; }

    // taken from /a/38396065
    public void OnAuthorization(AuthorizationFilterContext context)
    {
        var contextFeatures = context.HttpContext.Features;
        var formFeature = contextFeatures.Get<IFormFeature>();

        if (formFeature == null || formFeature.Form == null)
        {
            // Setting length limit when the form request is not yet being read
            contextFeatures.Set<IFormFeature>(new FormFeature(context.HttpContext.Request, _formOptions));
        }
    }
}

操作方法中的用法示例:

Usage example in action method:

[HttpPost("{company_id}/updateLogo")]
[RequestSizeLimit(valueCountLimit: 2147483648)] // e.g. 2 GB request limit
public async Task<IActionResult> updateCompanyLogo(IFormFile imgfile, int company_id)
{
    // contents removed for brevity
}

注意::如果正在使用最新版本的ASP.NET Core，请将名为ValueCountLimit的属性更改为KeyCountLimit.

NB: If latest version of ASP.NET Core is being used, change property named ValueCountLimit to KeyCountLimit.

更新:Order属性必须包含在属性类中，因为它是已实现的接口IOrderedFilter的成员.

Update: The Order property must be included on attribute class because it is a member of implemented interface IOrderedFilter.

类似的问题:

表单提交导致"InvalidDataException" :超出了表单值计数限制1024."

Request.Form引发异常

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