原文:Net Core 下 Newtonsoft.Json 转换字符串 null 替换成string.Empty
public class NullToEmptyStringResolver : DefaultContractResolver
{
/// <summary>
/// 创建属性
/// </summary>
/// <param name="type">类型</param>
/// <param name="memberSerialization">序列化成员</param>
/// <returns></returns>
protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
{
return type.GetProperties()
.Select(x =>
{
var property = CreateProperty(x, memberSerialization);
property.ValueProvider = new NullToEmptyStringValueProvider(x);
return property;
}).ToList();
} /// <inheritdoc />
/// <summary>
/// 小写
/// </summary>
/// <param name="propertyName"></param>
/// <returns></returns>
protected override string ResolvePropertyName(string propertyName)
{
return propertyName.ToLower();
}
}
public class NullToEmptyStringValueProvider : IValueProvider
{
private readonly PropertyInfo _memberInfo; /// <summary>
/// 构造函数
/// </summary>
/// <param name="memberInfo"></param>
public NullToEmptyStringValueProvider(PropertyInfo memberInfo)
{
_memberInfo = memberInfo;
} /// <inheritdoc />
/// <summary>
/// 获取Value
/// </summary>
/// <param name="target"></param>
/// <returns></returns>
public object GetValue(object target)
{
var result = _memberInfo.GetValue(target);
if (_memberInfo.PropertyType == typeof(string) && result == Convert.DBNull)
{
result = string.Empty;
} return result; } /// <inheritdoc />
/// <summary>
/// 设置Value
/// </summary>
/// <param name="target"></param>
/// <param name="value"></param>
public void SetValue(object target, object value)
{
_memberInfo.SetValue(target, value);
}
}