优化

app/src/main/java/io/legado/app/utils/ViewExtensions.kt

@@ -126,13 +126,17 @@ fun View.visible(visible: Boolean) {
     }
 }
 
-fun View.screenshot(): Bitmap {
+fun View.screenshot(): Bitmap? {
+    return if (width > 0 && height > 0) {
         val screenshot = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)
         val c = Canvas(screenshot)
         c.translate(-scrollX.toFloat(), -scrollY.toFloat())
         this.draw(c)
         c.setBitmap(null)
-    return screenshot
+        screenshot
+    } else {
+        null
+    }
 }
 
 fun SeekBar.progressAdd(int: Int) {