Change KMPDFFactory.readerView background color according different ReadMode

src/main/java/com/kdanmobile/reader/ReaderViewModel.kt

@@ -8,6 +8,7 @@ import android.graphics.Bitmap
 import android.graphics.Color
 import android.graphics.RectF
 import android.net.Uri
+import android.support.v4.content.ContextCompat
 import com.kdanmobile.kmpdfkit.annotation.Annotation
 import com.kdanmobile.kmpdfkit.annotation.bean.*
 import com.kdanmobile.kmpdfkit.contextmenu.KMPDFMenuItem
@@ -579,6 +580,14 @@ class ReaderViewModel(private val pdfSdkLicense: String, private val pdfSdkRsaMs
     private fun updateReadMode() {
         kmpdfDocumentController?.readMode = readMode.mode
         kmpdfDocumentController?.refresh(false)
+        kmpdfFactory?.readerView?.context?.also {
+            val colorResId = when (readMode) {
+                ReadMode.READ_MODE_DAY -> R.color.color_bolder
+                ReadMode.READ_MODE_NIGHT -> R.color.black_38
+                else -> R.color.color_divier
+            }
+            kmpdfFactory?.readerView?.setBackgroundColor(ContextCompat.getColor(it, colorResId))
+        }
     }
 
     private fun updateCrop() {

src/main/res/values/colors.xml

@@ -7,6 +7,8 @@
     <color name="picton_blue">#30AFFD</color>
     <color name="bright_blue">#0077fd</color>
     <color name="bright_blue_38">#610077fd</color>
+    <color name="color_bolder">#DEDDDE</color>
+    <color name="color_divier">#CECDCE</color>
 
     <color name="reader_top_toolbar_bg">#FFFFFF</color>
     <color name="reader_bottom_toolbar_bg">#FFFFFF</color>