init

android/src/main/java/com/example/ch34/Ch34Plugin.java

@@ -56,6 +56,18 @@ public class Ch34Plugin implements FlutterPlugin, MethodCallHandler {
     /** 全局 WCHUARTManager 实例 */
     private WCHUARTManager manager;
 
+    /**
+     * 维护 Modem 信号绝对电平状态。
+     *
+     * WCH SDK IModemStatus.onStatusChanged 的参数 isDSRRaised/isCTSRaised/isDCDRaised/isRINGRaised
+     * 在字面上是"上升沿标志"，但实际观察表明其行为符合电平值（true=高电平，false=低电平）。
+     * 为确保语义明确且不受 SDK 行为变化影响，在此维护绝对电平状态。
+     */
+    private boolean currentDSRLevel = false;
+    private boolean currentCTSLevel = false;
+    private boolean currentDCDLevel = false;
+    private boolean currentRINGLevel = false;
+
     @Override
     public void onAttachedToEngine(@NonNull FlutterPluginBinding binding) {
         channel = new MethodChannel(binding.getBinaryMessenger(), "ch34");
@@ -545,6 +557,7 @@ public class Ch34Plugin implements FlutterPlugin, MethodCallHandler {
                 manager.disconnect(device);
                 openedDevices.remove(deviceName);
                 usbStateStreamHandler.notifyStateChanged(deviceName, false);
+                resetModemStatusLevels();
             }
             result.success(null);
         } catch (Exception e) {
@@ -578,6 +591,7 @@ public class Ch34Plugin implements FlutterPlugin, MethodCallHandler {
             }
         }
         openedDevices.clear();
+        resetModemStatusLevels();
     }
 
     // ==================== GPIO 功能 ====================
@@ -752,14 +766,22 @@ public class Ch34Plugin implements FlutterPlugin, MethodCallHandler {
                 @Override
                 public void onStatusChanged(int serialNumber, boolean isDCDRaised,
                         boolean isDSRRaised, boolean isCTSRaised, boolean isRINGRaised) {
+                    // 根据 SDK 回调参数更新绝对电平状态
+                    // WCH SDK 的 isDSRRaised 等参数在每次状态变化回调中表示该信号的
+                    // 当前电平值：true=高电平，false=低电平
+                    currentDCDLevel = isDCDRaised;
+                    currentDSRLevel = isDSRRaised;
+                    currentCTSLevel = isCTSRaised;
+                    currentRINGLevel = isRINGRaised;
+
                     Log.d(TAG, "Modem onStatusChanged: serial=" + serialNumber
-                            + " dcd=" + isDCDRaised + " dsr=" + isDSRRaised
+                            + " dcd=" + currentDCDLevel + " dsr=" + currentDSRLevel
-                            + " cts=" + isCTSRaised + " ri=" + isRINGRaised);
+                            + " cts=" + currentCTSLevel + " ri=" + currentRINGLevel);
                     Map<String, Object> map = new HashMap<>();
-                    map.put("dcd", isDCDRaised);
+                    map.put("dcd", currentDCDLevel);
-                    map.put("dsr", isDSRRaised);
+                    map.put("dsr", currentDSRLevel);
-                    map.put("cts", isCTSRaised);
+                    map.put("cts", currentCTSLevel);
-                    map.put("ri", isRINGRaised);
+                    map.put("ri", currentRINGLevel);
                     Log.d(TAG, "Sending modem status to Flutter: " + map);
                     modemStreamHandler.sendStatus(map);
                 }
@@ -786,6 +808,8 @@ public class Ch34Plugin implements FlutterPlugin, MethodCallHandler {
     private void removeModemStatusCallback(@NonNull MethodCall call, @NonNull Result result) {
         try {
             modemStreamHandler.stopListening();
+            // 重置 Modem 信号绝对电平状态，防止重连时状态残留
+            resetModemStatusLevels();
             result.success(null);
         } catch (Exception e) {
             Log.e(TAG, "removeModemStatusCallback error", e);
@@ -858,6 +882,18 @@ public class Ch34Plugin implements FlutterPlugin, MethodCallHandler {
 
     // ==================== 辅助方法 ====================
 
+    /**
+     * 重置 Modem 信号绝对电平状态。
+     *
+     * 在移除 Modem 回调或关闭设备时调用，确保下次注册回调时状态干净。
+     */
+    private void resetModemStatusLevels() {
+        currentDSRLevel = false;
+        currentCTSLevel = false;
+        currentDCDLevel = false;
+        currentRINGLevel = false;
+    }
+
     private void ensureManagerInitialized() {
         if (manager == null) {
             Application app;