Asp.net Core 3.0中关于DateTime格式化的方法

不特别设置的话，对于DateTime类型默认格式化为带T的字符串，如"yyyy-MM-ddTHH:mm:ss"。

如果需要自定义这个格式，需要在Startup类的ConfigureServices方法中指定

            //配置响应格式
            services.AddJsonOptions(options =>
            {
                options.JsonSerializerOptions.Converters.Add(new DateTimeConverter());
                options.JsonSerializerOptions.Converters.Add(new DateTimeNullConverter());
            }).SetCompatibilityVersion(CompatibilityVersion.Version_3_0);

新建格式化处理类

    public class DateTimeNullConverter : JsonConverter<DateTime?>
    {
        public override DateTime? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
            => string.IsNullOrEmpty(reader.GetString()) ? default(DateTime?) : DateTime.Parse(reader.GetString());

        public override void Write(Utf8JsonWriter writer, DateTime? value, JsonSerializerOptions options)
            => writer.WriteStringValue(value?.ToString("yyyy-MM-dd HH:mm"));
    }

    public class DateTimeConverter : JsonConverter<DateTime>
    {
        public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
            => DateTime.Parse(reader.GetString());

        public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)
            => writer.WriteStringValue(value.ToString("yyyy-MM-dd HH:mm"));
    }