这些链接对我没有帮助：
例：
//Model:
public class Group
{
public int Id { get; set; }
public File File { get; set; }
}
//Controller:
[HttpPost]
public void SaveGroup([FromBody]Group group) {}
//Formatter:
public class MultipartFormFormatter : MediaTypeFormatter
{
private const string StringMultipartMediaType = "multipart/form-data";
public MultipartFormFormatter()
{
this.SupportedMediaTypes.Add(new MediaTypeHeaderValue(StringMultipartMediaType));
}
public override bool CanReadType(Type type)
{
return true;
}
public override bool CanWriteType(Type type)
{
return false;
}
public async override Task<object> ReadFromStreamAsync(Type type,Stream readStream,HttpContent content,IFormatterLogger formatterLogger)
{
//Implementation? What here should be?
}
}
ReadFromStreamAsync方法应该返回什么？
如何使它能够正确地将参数传递给动作？
解决方法
public class MultipartFormFormatter : FormUrlEncodedMediaTypeFormatter
{
private const string StringMultipartMediaType = "multipart/form-data";
private const string StringApplicationMediaType = "application/octet-stream";
public MultipartFormFormatter()
{
this.SupportedMediaTypes.Add(new MediaTypeHeaderValue(StringMultipartMediaType));
this.SupportedMediaTypes.Add(new MediaTypeHeaderValue(StringApplicationMediaType));
}
public override bool CanReadType(Type type)
{
return true;
}
public override bool CanWriteType(Type type)
{
return false;
}
public override async Task<object> ReadFromStreamAsync(Type type,IFormatterLogger formatterLogger)
{
var parts = await content.ReadAsMultipartAsync();
var obj = Activator.CreateInstance(type);
var propertiesFromObj = obj.GetType().GetRuntimeProperties().ToList();
foreach (var property in propertiesFromObj.Where(x => x.PropertyType == typeof(FileModel)))
{
var file = parts.Contents.FirstOrDefault(x => x.Headers.ContentDisposition.Name.Contains(property.Name));
if (file == null || file.Headers.ContentLength <= 0) continue;
try
{
var fileModel = new FileModel(file.Headers.ContentDisposition.FileName,Convert.ToInt32(file.Headers.ContentLength),ReadFully(file.ReadAsStreamAsync().Result));
property.SetValue(obj,fileModel);
}
catch (Exception e)
{
}
}
foreach (var property in propertiesFromObj.Where(x => x.PropertyType != typeof(FileModel)))
{
var formData = parts.Contents.FirstOrDefault(x => x.Headers.ContentDisposition.Name.Contains(property.Name));
if (formData == null) continue;
try
{
var strValue = formData.ReadAsStringAsync().Result;
var valueType = Nullable.GetUnderlyingType(property.PropertyType) ?? property.PropertyType;
var value = Convert.ChangeType(strValue,valueType);
property.SetValue(obj,value);
}
catch (Exception e)
{
}
}
return obj;
}
private byte[] ReadFully(Stream input)
{
var buffer = new byte[16 * 1024];
using (var ms = new MemoryStream())
{
int read;
while ((read = input.Read(buffer,buffer.Length)) > 0)
{
ms.Write(buffer,read);
}
return ms.ToArray();
}
}
}
public class FileModel
{
public FileModel(string filename,int contentLength,byte[] content)
{
Filename = filename;
ContentLength = contentLength;
Content = content;
}
public string Filename { get; set; }
public int ContentLength { get; set; }
public byte[] Content { get; set; }
}
