diff --git a/assets/middleLayer_for_DG/scene/middleLayer_for_DG.fire b/assets/middleLayer_for_DG/scene/middleLayer_for_DG.fire
index 787993244f70487b1b99a859cb2631fa8a9249c2..ddcabbeb150c9275a085286f9d97fd21187f7cfe 100644
--- a/assets/middleLayer_for_DG/scene/middleLayer_for_DG.fire
+++ b/assets/middleLayer_for_DG/scene/middleLayer_for_DG.fire
@@ -98,8 +98,8 @@
     },
     "_contentSize": {
       "__type__": "cc.Size",
-      "width": 1280,
-      "height": 720
+      "width": 1920,
+      "height": 1080
     },
     "_anchorPoint": {
       "__type__": "cc.Vec2",
@@ -110,8 +110,8 @@
       "__type__": "TypedArray",
       "ctor": "Float64Array",
       "array": [
-        640,
-        360,
+        960,
+        540,
         0,
         0,
         0,
@@ -243,8 +243,8 @@
     "_enabled": true,
     "_designResolution": {
       "__type__": "cc.Size",
-      "width": 1280,
-      "height": 720
+      "width": 1920,
+      "height": 1080
     },
     "_fitWidth": false,
     "_fitHeight": true,
@@ -337,8 +337,8 @@
     },
     "_contentSize": {
       "__type__": "cc.Size",
-      "width": 1280,
-      "height": 720
+      "width": 1920,
+      "height": 1080
     },
     "_anchorPoint": {
       "__type__": "cc.Vec2",
@@ -349,8 +349,8 @@
       "__type__": "TypedArray",
       "ctor": "Float64Array",
       "array": [
-        640,
-        360,
+        960,
+        540,
         0,
         0,
         0,
@@ -382,7 +382,7 @@
       "__id__": 8
     },
     "_children": [],
-    "_active": false,
+    "_active": true,
     "_components": [
       {
         "__id__": 10
@@ -405,8 +405,8 @@
     },
     "_contentSize": {
       "__type__": "cc.Size",
-      "width": 171,
-      "height": 146
+      "width": 131,
+      "height": 131
     },
     "_anchorPoint": {
       "__type__": "cc.Vec2",
@@ -417,15 +417,15 @@
       "__type__": "TypedArray",
       "ctor": "Float64Array",
       "array": [
-        -577.25,
-        303.5,
+        -863.522,
+        453.12800000000004,
         0,
         0,
         0,
         0,
         1,
-        0.5,
-        0.5,
+        1,
+        1,
         1
       ]
     },
@@ -521,9 +521,9 @@
     "alignMode": 2,
     "_target": null,
     "_alignFlags": 9,
-    "_left": 20,
+    "_left": 30.977999999999952,
     "_right": 0,
-    "_top": 20,
+    "_top": 21.371999999999957,
     "_bottom": 0,
     "_verticalCenter": 0,
     "_horizontalCenter": 0,
@@ -553,7 +553,7 @@
     "_srcBlendFactor": 770,
     "_dstBlendFactor": 771,
     "_spriteFrame": {
-      "__uuid__": "dae06413-7c06-4a99-8a27-fc098af38812"
+      "__uuid__": "57bdc862-1a68-4657-9b66-b5115d097b7e"
     },
     "_type": 0,
     "_sizeMode": 1,
@@ -612,8 +612,8 @@
       "__type__": "TypedArray",
       "ctor": "Float64Array",
       "array": [
-        437.75,
-        303.5,
+        757.75,
+        483.5,
         0,
         0,
         0,
@@ -807,8 +807,8 @@
       "__type__": "TypedArray",
       "ctor": "Float64Array",
       "array": [
-        567.75,
-        303.5,
+        887.75,
+        483.5,
         0,
         0,
         0,
diff --git a/assets/middleLayer_for_DG/script/middleLayer.ts b/assets/middleLayer_for_DG/script/middleLayer.ts
index a7b438107ae5e2886486761f319b52755a3bff5b..a3935742b3bc358389c203b8338ac80b563a69f8 100644
--- a/assets/middleLayer_for_DG/script/middleLayer.ts
+++ b/assets/middleLayer_for_DG/script/middleLayer.ts
@@ -42,6 +42,8 @@ export default class NewClass extends middleLayerBase {
       return;
     }
     this.loadOnlineCourseWare(this.course_id, false, this.courseware_id);
+
+    this.initListener();
   }
 
   onHomeworkFinish(callBack, data = null) {
@@ -63,8 +65,23 @@ export default class NewClass extends middleLayerBase {
     });
   }
 
+  exitFlag;
   initListener() {
-    
+    const ExitBtn = cc.find('middleLayer/ExitBtn');
+    ExitBtn.on("click", () => {
+      if (this.exitFlag) {
+        return;
+      }
+      this.exitFlag = true;
+      cc.tween(ExitBtn)
+        .to(0.1, { scaleX: 0.9, scaleY: 1.1 })
+        .to(0.1, { scaleX: 1.1, scaleY: 0.9 })
+        .to(0.1, { scaleX: 1, scaleY: 1 })
+        .call(() => {
+          this.callNativeFunction({ name: "exit", value: "" });
+        })
+        .start();
+    });
   }
 
   reWriteAir() {
@@ -166,12 +183,18 @@ export default class NewClass extends middleLayerBase {
         paramStr
       );
     } else {
-      console.error("非源生环境,需要从URL中获取必要的参数");
-      const token = this.getQueryString("token");
-      const course_id = this.getQueryString("course_id");
-      const courseware_id = this.getQueryString("courseware_id");
-      const resobj = { bundleInfo: {token,course_id,courseware_id}};
-      return JSON.stringify(resobj);
+      if (param.name == "loadSceneList") {
+        // Mock数据
+        console.error("非源生环境,需要从URL中获取必要的参数");
+        const token = this.getQueryString("token");
+        const course_id = this.getQueryString("course_id");
+        const courseware_id = this.getQueryString("courseware_id");
+        const resobj = { bundleInfo: {token,course_id,courseware_id}};
+        return JSON.stringify(resobj);
+      }
+      if (param.name == "exit") {
+        console.log("==调用退出方法成功==参数:", paramStr);
+      }
     }
   }
 }
diff --git a/assets/middleLayer_for_DG/script/util.js b/assets/middleLayer_for_DG/script/util.js
index 940465417e94173b29053d91b22f6d8a327938c3..15ed69183faf19ec90563180649cb0516345ef21 100644
--- a/assets/middleLayer_for_DG/script/util.js
+++ b/assets/middleLayer_for_DG/script/util.js
@@ -340,40 +340,3 @@ export function showTrebleFirework(baseNode, rabbonList) {
   showFireworks(left);
   showFireworks(right);
 }
-
-export function onHomeworkFinish() {
-  const middleLayer = cc.find('middleLayer');
-  if (middleLayer) {
-    const middleLayerComponent = middleLayer.getComponent('middleLayer');
-    if (middleLayerComponent.role == 'student') {
-      middleLayerComponent.onHomeworkFinish(() => { });
-    }
-  } else {
-    console.log('onHomeworkFinish');
-  }
-}
-
-export function callMiddleLayerFunction(apiName, data, callback) {
-  const middleLayer = cc.find('middleLayer');
-  if (middleLayer) {
-    const middleLayerComponent = middleLayer.getComponent('middleLayer');
-    middleLayerComponent.callMiddleLayerFunction(apiName, data, callback);
-  } else {
-    console.log('callMiddleLayerFunction: ' + apiName);
-  }
-}
-
-export function login() {
-  const middleLayer = cc.find('middleLayer');
-  if (middleLayer) {
-    const middleLayerComponent = middleLayer.getComponent('middleLayer');
-    middleLayerComponent.callMiddleLayerFunction('NS_login', {
-      userName: 'username123',
-      password: '1234567'
-    }, (result) => {
-      console.log(result);
-    });
-  } else {
-    console.log('NS_login');
-  }
-}
\ No newline at end of file
diff --git a/assets/middleLayer_for_DG/textures/btn_return.png b/assets/middleLayer_for_DG/textures/btn_return.png
new file mode 100644
index 0000000000000000000000000000000000000000..a61d8fe690daf25ae58c1a564abd6d0ee0c0c577
Binary files /dev/null and b/assets/middleLayer_for_DG/textures/btn_return.png differ
diff --git a/assets/middleLayer_for_DG/textures/btn_return.png.meta b/assets/middleLayer_for_DG/textures/btn_return.png.meta
new file mode 100644
index 0000000000000000000000000000000000000000..b0088a860f1523dea907eccb549b92916e15a348
--- /dev/null
+++ b/assets/middleLayer_for_DG/textures/btn_return.png.meta
@@ -0,0 +1,36 @@
+{
+  "ver": "2.3.5",
+  "uuid": "b8f292f2-73ea-41e1-9d85-993bc4197375",
+  "type": "sprite",
+  "wrapMode": "clamp",
+  "filterMode": "bilinear",
+  "premultiplyAlpha": false,
+  "genMipmaps": false,
+  "packable": true,
+  "width": 131,
+  "height": 131,
+  "platformSettings": {},
+  "subMetas": {
+    "btn_return": {
+      "ver": "1.0.4",
+      "uuid": "57bdc862-1a68-4657-9b66-b5115d097b7e",
+      "rawTextureUuid": "b8f292f2-73ea-41e1-9d85-993bc4197375",
+      "trimType": "auto",
+      "trimThreshold": 1,
+      "rotated": false,
+      "offsetX": 0,
+      "offsetY": 0,
+      "trimX": 0,
+      "trimY": 0,
+      "width": 131,
+      "height": 131,
+      "rawWidth": 131,
+      "rawHeight": 131,
+      "borderTop": 0,
+      "borderBottom": 0,
+      "borderLeft": 0,
+      "borderRight": 0,
+      "subMetas": {}
+    }
+  }
+}
\ No newline at end of file