refactor: ♻️ 2.0 (#3)

src/backend/NSExt/Extensions/LongExtensions.cs

@@ -0,0 +1,42 @@
+namespace NSExt.Extensions;
+
+/// <summary>
+///     LongExtensions
+/// </summary>
+public static class LongExtensions
+{
+    /// <summary>
+    ///     判断枚举是否包含某个位
+    /// </summary>
+    public static bool HasFlag<T>(this long me, T flag)
+        where T : Enum
+    {
+        var val = (long)(object)flag;
+        return (me & val) == val;
+    }
+
+    /// <summary>
+    ///     生成随机数
+    /// </summary>
+    /// <param name="me">me</param>
+    public static long Rand(this long[] me)
+    {
+        return new Random(Guid.NewGuid().GetHashCode()).NextInt64(me[0], me[1]);
+    }
+
+    /// <summary>
+    ///     1970毫秒数转换成日期对象
+    /// </summary>
+    public static DateTime Time(this long msFrom1970)
+    {
+        return DateTime.UnixEpoch.AddMilliseconds(msFrom1970).ToLocalTime();
+    }
+
+    /// <summary>
+    ///     ToString 的 Invariant 版本
+    /// </summary>
+    public static string ToInvString(this long me)
+    {
+        return me.ToString(CultureInfo.InvariantCulture);
+    }
+}