src/Hotline.Share/Tools/DataMaskExtensions.cs

@@ -10,6 +10,9 @@ public static class DataMaskExtensions
 {
     public static string Mask(this string original, int startIndex = 0, int length = 4)
     {
+        if (original.IsNullOrEmpty()) return original;
+        if (original.Length <= startIndex + length) return original;
+
         var headStr = original.Substring(0, startIndex);
         var tailStr = original.Substring(startIndex + length);
         var sb = new StringBuilder(length);