可空类型

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/// <summary>
/// Extensions.Nullable
/// 扩展 - 可空类型
/// </summary>
public static partial class Extensions
{
    /// <summary>
    /// 安全返回值
    /// </summary>
    /// <param name="value">可空值</param>
    public static T SafeValue<T>(this T? value) where T : struct
    {
        return value ?? default(T);
    }
    /// <summary>
    /// 是否包含
    /// </summary>
    /// <param name="obj">字串</param>
    /// <param name="value">包含字串</param>
    /// <returns></returns>
    public static bool ContainsEx(this string obj,string value)
    {
        if (string.IsNullOrEmpty(obj))
        {
            return false;
        }
        else {
            return obj.Contains(value);
        }
    }
    /// <summary>
    /// 字串是否在指定字串中存在
    /// </summary>
    /// <param name="obj">字串</param>
    /// <param name="value">被包含字串</param>
    /// <returns></returns>
    public static bool Like(this string obj, string value)
    {
        if (string.IsNullOrEmpty(value))
        {
            return false;
        }
        else if (string.IsNullOrEmpty(obj))
        {
            return false;
        }
        else
        {
            if (value.IndexOf(obj) != -1)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
    }
}