diff --git a/app/src/main/java/io/legado/app/ui/widget/anima/RotateLoading.kt b/app/src/main/java/io/legado/app/ui/widget/anima/RotateLoading.kt
index 606e34686..d2bd8c0a8 100644
--- a/app/src/main/java/io/legado/app/ui/widget/anima/RotateLoading.kt
+++ b/app/src/main/java/io/legado/app/ui/widget/anima/RotateLoading.kt
@@ -21,7 +21,7 @@ import io.legado.app.utils.dp
  */
 class RotateLoading : View {
 
-    private var mPaint: Paint? = null
+    private lateinit var mPaint: Paint
 
     private var loadingRectF: RectF? = null
     private var shadowRectF: RectF? = null
@@ -77,11 +77,11 @@ class RotateLoading : View {
         }
         speedOfArc = (speedOfDegree / 4).toFloat()
         mPaint = Paint()
-        mPaint?.color = loadingColor
-        mPaint?.isAntiAlias = true
-        mPaint?.style = Paint.Style.STROKE
-        mPaint?.strokeWidth = thisWidth.toFloat()
-        mPaint?.strokeCap = Paint.Cap.ROUND
+        mPaint.color = loadingColor
+        mPaint.isAntiAlias = true
+        mPaint.style = Paint.Style.STROKE
+        mPaint.strokeWidth = thisWidth.toFloat()
+        mPaint.strokeCap = Paint.Cap.ROUND
     }
 
     override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
@@ -112,13 +112,17 @@ class RotateLoading : View {
             return
         }
 
-        mPaint?.color = Color.parseColor("#1a000000")
-        canvas.drawArc(shadowRectF!!, topDegree.toFloat(), arc, false, mPaint!!)
-        canvas.drawArc(shadowRectF!!, bottomDegree.toFloat(), arc, false, mPaint!!)
+        mPaint.color = Color.parseColor("#1a000000")
+        shadowRectF?.let {
+            canvas.drawArc(it, topDegree.toFloat(), arc, false, mPaint)
+            canvas.drawArc(it, bottomDegree.toFloat(), arc, false, mPaint)
+        }
 
-        mPaint?.color = loadingColor
-        canvas.drawArc(loadingRectF!!, topDegree.toFloat(), arc, false, mPaint!!)
-        canvas.drawArc(loadingRectF!!, bottomDegree.toFloat(), arc, false, mPaint!!)
+        mPaint.color = loadingColor
+        loadingRectF?.let {
+            canvas.drawArc(it, topDegree.toFloat(), arc, false, mPaint)
+            canvas.drawArc(it, bottomDegree.toFloat(), arc, false, mPaint)
+        }
 
         topDegree += speedOfDegree
         bottomDegree += speedOfDegree