示波器修改：visa连接方式+截图保存

DeviceCommand/Base/IVisa.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace DeviceCommand.Base
+{
+    /// <summary>
+    /// VISA SCPI 通信接口：与 <see cref="ITcp"/> 暴露一致的异步收发能力，
+    /// 使 SCPI 设备类可在 Tcp 与 VISA 传输之间平滑切换。
+    /// </summary>
+    public interface IVisa : IBaseInterface, IDisposable
+    {
+        /// <summary>发送原始二进制数据。</summary>
+        Task SendAsync(byte[] buffer, CancellationToken ct = default);
+
+        /// <summary>发送字符串命令（SCPI 命令自带结束符）。</summary>
+        Task SendAsync(string str, CancellationToken ct = default);
+
+        /// <summary>读取指定长度的原始字节。</summary>
+        Task<byte[]> ReadAsync(int length, CancellationToken ct = default);
+
+        /// <summary>读取一行字符串，直到遇到结束符。</summary>
+        Task<string> ReadAsync(string delimiter = "\n", CancellationToken ct = default);
+
+        /// <summary>发送命令并读取一行响应。</summary>
+        Task<string> WriteReadAsync(string command, string delimiter = "\n", CancellationToken ct = default);
+
+        /// <summary>发送查询命令并读取 IEEE 488.2 定长二进制块，自动剥离块头（#N&lt;长度&gt;）后只返回纯数据字节（用于截图/波形等大块数据）。</summary>
+        Task<byte[]> ReadAllBytesAsync(string queryCommand, CancellationToken ct = default);
+    }
+}