ASP.NET Core 3.x RESTful API学习记录--自定义模型绑定

 public class ArrayModelBinder: IModelBinder
    {
        /// <summary>
        /// bindingContext model的源数据
        /// </summary>
        /// <param name="bindingContext"></param>
        /// <returns></returns>
        public Task BindModelAsync(ModelBindingContext bindingContext)
        {
            if (!bindingContext.ModelMetadata.IsEnumerableType)
            {
                bindingContext.Result = ModelBindingResult.Failed();//返回失败
                return Task.CompletedTask;
            }

            var value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName).ToString();

            if (string.IsNullOrWhiteSpace(value))
            {
                bindingContext.Result = ModelBindingResult.Success(null);
                return Task.CompletedTask;
            }

            var elementType = bindingContext.ModelType.GetTypeInfo().GenericTypeArguments[0];
            var converter = TypeDescriptor.GetConverter(elementType);//转换器

            var values = value.Split(new[] {","}, StringSplitOptions.RemoveEmptyEntries)
                .Select(x => converter.ConvertFromString(x.Trim())).ToArray();

            var typedValues = Array.CreateInstance(elementType, values.Length);
            values.CopyTo(typedValues, 0);
            bindingContext.Model = typedValues;

            bindingContext.Result = ModelBindingResult.Success(bindingContext.Model);
            return Task.CompletedTask;
        }
    }