优化

app/src/main/java/io/legado/app/model/localBook/LocalBook.kt

@@ -268,7 +268,7 @@ object LocalBook {
             var doc = treeDoc!!.findFile(fileName)
             if (doc == null) {
                 doc = treeDoc.createFile(FileUtils.getMimeType(fileName), fileName)
-                    ?: throw SecurityException("Permission Denial")
+                    ?: throw SecurityException("请重新设置书籍保存位置\nPermission Denial")
             }
             appCtx.contentResolver.openOutputStream(doc.uri)!!.use { oStream ->
                 inputStream.copyTo(oStream)

app/src/main/java/io/legado/app/ui/association/FileAssociationActivity.kt

@@ -145,7 +145,7 @@ class FileAssociationActivity :
                             if (doc == null || fileDoc.lastModified > doc.lastModified()) {
                                 if (doc == null) {
                                     doc = treeDoc.createFile(FileUtils.getMimeType(name), name)
-                                        ?: throw SecurityException("Permission Denial")
+                                        ?: throw SecurityException("请重新设置书籍保存位置\nPermission Denial")
                                 }
                                 contentResolver.openOutputStream(doc.uri)!!.use { oStream ->
                                     inputStream.copyTo(oStream)

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

@@ -60,8 +60,8 @@ object ImageUtils {
     ): String? {
         return when (source) {
             is BookSource ->
-             if (isCover) source?.coverDecodeJs else source?.getContentRule()?.imageDecode
+                if (isCover) source.coverDecodeJs else source.getContentRule().imageDecode
-          is RssSource -> source?.coverDecodeJs
+            is RssSource -> source.coverDecodeJs
             else -> null
         }
     }