diff --git a/app/src/main/java/io/legado/app/ui/book/read/page/delegate/PageDelegate.kt b/app/src/main/java/io/legado/app/ui/book/read/page/delegate/PageDelegate.kt
index 681159059..fec677deb 100644
--- a/app/src/main/java/io/legado/app/ui/book/read/page/delegate/PageDelegate.kt
+++ b/app/src/main/java/io/legado/app/ui/book/read/page/delegate/PageDelegate.kt
@@ -34,14 +34,9 @@ abstract class PageDelegate(protected val pageView: PageView) :
     protected var touchX: Float = 0f
     protected var touchY: Float = 0f
 
-    protected val nextPage: ContentView
-        get() = pageView.nextPage
-
-    protected val curPage: ContentView
-        get() = pageView.curPage
-
-    protected val prevPage: ContentView
-        get() = pageView.prevPage
+    protected val nextPage: ContentView get() = pageView.nextPage
+    protected val curPage: ContentView get() = pageView.curPage
+    protected val prevPage: ContentView get() = pageView.prevPage
 
     protected var bitmap: Bitmap? = null
 
@@ -90,7 +85,7 @@ abstract class PageDelegate(protected val pageView: PageView) :
         touchY = y
 
         if (invalidate) {
-            pageView.postInvalidate()
+            pageView.invalidate()
         }
 
         onScroll()
@@ -187,12 +182,11 @@ abstract class PageDelegate(protected val pageView: PageView) :
 
     abstract fun onAnimStart()//scroller start
 
-    abstract fun onDraw(canvas: Canvas)//绘制
+    open fun onDraw(canvas: Canvas) {}//绘制
 
     abstract fun onAnimStop()//scroller finish
 
-    open fun onScroll() {//移动contentView， slidePage
-    }
+    open fun onScroll() {}//移动contentView， slidePage
 
     @CallSuper
     open fun setDirection(direction: Direction) {
diff --git a/app/src/main/java/io/legado/app/ui/book/read/page/delegate/ScrollPageDelegate.kt b/app/src/main/java/io/legado/app/ui/book/read/page/delegate/ScrollPageDelegate.kt
index 894e4b9b8..eca83b12a 100644
--- a/app/src/main/java/io/legado/app/ui/book/read/page/delegate/ScrollPageDelegate.kt
+++ b/app/src/main/java/io/legado/app/ui/book/read/page/delegate/ScrollPageDelegate.kt
@@ -1,6 +1,5 @@
 package io.legado.app.ui.book.read.page.delegate
 
-import android.graphics.Canvas
 import android.view.MotionEvent
 import android.view.VelocityTracker
 import io.legado.app.ui.book.read.page.PageView
@@ -21,7 +20,7 @@ class ScrollPageDelegate(pageView: PageView) : PageDelegate(pageView) {
         )
     }
 
-    override fun onDraw(canvas: Canvas) {
+    override fun onScroll() {
         curPage.onScroll(touchY - lastY)
     }