优化

app/src/main/java/io/legado/app/ui/book/read/config/BgTextConfigDialog.kt

@@ -353,7 +353,11 @@ class BgTextConfigDialog : BaseDialogFragment(R.layout.dialog_read_bg_text) {
     private fun setBgFromUri(uri: Uri) {
         readUri(uri) { fileDoc, inputStream ->
             var file = requireContext().externalFiles
-            file = FileUtils.createFileIfNotExist(file, "bg", fileDoc.name)
+            val suffix = fileDoc.name.substringAfterLast(".")
+            val fileName = uri.inputStream(requireContext())!!.use {
+                MD5Utils.md5Encode(it) + ".$suffix"
+            }
+            file = FileUtils.createFileIfNotExist(file, "bg", fileName)
             FileOutputStream(file).use { outputStream ->
                 inputStream.copyTo(outputStream)
             }

app/src/main/java/io/legado/app/utils/MD5Utils.kt

@@ -1,6 +1,8 @@
 package io.legado.app.utils
 
 import cn.hutool.crypto.digest.DigestUtil
+import java.io.InputStream
+
 /**
  * 将字符串转化为MD5
  */
@@ -11,6 +13,10 @@ object MD5Utils {
         return DigestUtil.digester("MD5").digestHex(str)
     }
 
+    fun md5Encode(inputStream: InputStream): String {
+        return DigestUtil.digester("MD5").digestHex(inputStream)
+    }
+
     fun md5Encode16(str: String): String {
         var reStr = md5Encode(str)
         reStr = reStr.substring(8, 24)