Exception:解析表达式出错。 内部错误：未将对象引用设置到对象的实例。 原始表达式：var clipboardData = Clipboard.GetDataObject(); object result = clipboardData.GetData(formats[0]); if (result is MemoryStream memoryStream) { memoryStream.Position = 0; byte[] buffer = new byte[memoryStream.Length]; memoryStream.Read(buffer, 0, buffer.Length); return Encoding.UTF8.GetString(buffer); }