初步这样

android/src/main/java/top/jerryyan/RN/A/FitFullScreen/FitModule.java

@@ -1,12 +1,22 @@
 package top.jerryyan.RN.A.FitFullScreen;
 
+import android.graphics.Point;
+import android.os.Build;
+import android.provider.Settings;
+import android.view.Display;
+import android.view.WindowManager;
+
 import com.facebook.react.bridge.ReactApplicationContext;
 import com.facebook.react.bridge.ReactContextBaseJavaModule;
 import com.facebook.react.bridge.ReactMethod;
 import com.facebook.react.bridge.Callback;
 
+import java.util.HashMap;
+import java.util.Map;
+
 public class FitModule extends ReactContextBaseJavaModule {
     private final ReactApplicationContext reactContext;
+    private final String MANUFACTURER = Build.MANUFACTURER;
 
     public FitModule(ReactApplicationContext reactContext) {
         super(reactContext);
@@ -15,12 +25,50 @@ public class FitModule extends ReactContextBaseJavaModule {
 
     @Override
     public String getName() {
-        return "Fit";
+        return "FitFullScreen";
+    }
+
+    @Override
+    public Map<String, Object> getConstants(){
+        final Map<String, Object> constants = new HashMap<>();
+        constants.put("MANUFACTURER", MANUFACTURER);
+        return constants;
+    }
+
+    private boolean _isVirtualNavigationBarExist(){
+        WindowManager windowManager = reactContext.getCurrentActivity().getWindowManager();
+        if(windowManager == null){
+            return false;
+        }
+        Display display = windowManager.getDefaultDisplay();
+        Point size = new Point();
+        Point realSize = new Point();
+        display.getSize(size);  // app绘制区域
+        display.getRealSize(realSize);
+        return realSize.y != size.y;
+    }
+
+    private boolean _isXiaoMiFullScreen(){
+        return Settings.Global.getInt(reactContext.getContentResolver(), "force_fsg_nav_bar", 0) != 0;
+    }
+
+    private boolean _isHuaWeiFullScreen(){
+        try {
+            reactContext.getClassLoader().loadClass("com.huawei.android.util.HwNotchSizeUtil");
+            return true;
+        } catch (ClassNotFoundException e) {
+            return false;
+        }
     }
 
     @ReactMethod
-    public void sampleMethod(String stringArgument, int numberArgument, Callback callback) {
-        // TODO: Implement some actually useful functionality
-        callback.invoke("Received numberArgument: " + numberArgument + " stringArgument: " + stringArgument);
+    public void checkFullScreen(Callback callback){
+        if ("xiaomi".equalsIgnoreCase(MANUFACTURER)) {
+            callback.invoke(_isXiaoMiFullScreen());
+        }
+    }
+    @ReactMethod
+    public void isNavBarExist(Callback callback){
+        callback.invoke(_isVirtualNavigationBarExist());
     }
 }

index.js

@@ -0,0 +1,3 @@
+import { NativeModules } from "react-native";
+
+export default NativeModules.FitFullScreen;