优化

app/src/main/java/io/legado/app/ui/book/cache/CacheActivity.kt

@@ -48,7 +48,6 @@ import io.legado.app.utils.flowWithLifecycleAndDatabaseChange
 import io.legado.app.utils.iconItemOnLongClick
 import io.legado.app.utils.isContentScheme
 import io.legado.app.utils.observeEvent
-import io.legado.app.utils.parseToUri
 import io.legado.app.utils.showDialogFragment
 import io.legado.app.utils.startService
 import io.legado.app.utils.toastOnUi
@@ -184,6 +183,7 @@ class CacheActivity : VMBaseActivity<ActivityCacheBookBinding, CacheViewModel>()
                     CacheBook.stop(this@CacheActivity)
                 }
             }
+
             R.id.menu_download_all -> {
                 if (!CacheBook.isRun) {
                     adapter.getItems().forEach { book ->
@@ -321,9 +321,7 @@ class CacheActivity : VMBaseActivity<ActivityCacheBookBinding, CacheViewModel>()
 
     override fun export(position: Int) {
         val path = ACache.get().getAsString(exportBookPathKey)
-        if (path.isNullOrEmpty()) {
+        if (path.isNullOrEmpty() || !FileDoc.fromDir(path).checkWrite()) {
-            selectExportFolder(position)
-        } else if (FileDoc.fromUri(path.parseToUri(), true).checkWrite() != true) {
             selectExportFolder(position)
         } else if (enableCustomExport()) {// 启用自定义导出 and 导出类型为Epub
             configExportSection(path, position)

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

@@ -304,14 +304,14 @@ fun FileDoc.delete() {
     asDocumentFile()?.delete()
 }
 
-fun FileDoc.checkWrite(): Boolean? {
+fun FileDoc.checkWrite(): Boolean {
     if (!isDir) {
         throw NoStackTraceException("只能检查目录")
     }
     asFile()?.let {
         return it.checkWrite()
     }
-    return asDocumentFile()?.checkWrite()
+    return asDocumentFile()!!.checkWrite()
 }
 
 /**
@@ -358,17 +358,22 @@ fun DocumentFile.readBytes(context: Context): ByteArray {
 }
 
 fun DocumentFile.checkWrite(): Boolean {
+    var file: DocumentFile? = null
     return try {
         val filename = System.currentTimeMillis().toString()
-        createFile(FileUtils.getMimeType(filename), filename)?.let {
+        file = createFile(FileUtils.getMimeType(filename), filename)
-            it.openOutputStream()?.let { out ->
+        file?.openOutputStream()?.let { out ->
-                out.use { }
+            out.bufferedWriter().use { it.write(filename) }
-                it.delete()
+            file.openInputStream()?.let { input ->
-                return true
+                input.bufferedReader().use {
+                    return it.readText() == filename
+                }
             }
         }
         false
     } catch (e: Exception) {
         false
+    } finally {
+        file?.delete()
     }
 }

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

@@ -70,14 +70,16 @@ fun File.createFolderReplace(): File {
 }
 
 fun File.checkWrite(): Boolean {
+    var file: File? = null
     return try {
         val filename = System.currentTimeMillis().toString()
-        val file = FileUtils.createFileIfNotExist(this, filename)
+        file = FileUtils.createFileIfNotExist(this, filename)
-        file.outputStream().use { }
+        file.outputStream().bufferedWriter().use { it.write(filename) }
-        file.delete()
+        file.inputStream().bufferedReader().use { it.readText() == filename }
-        true
     } catch (e: Exception) {
         false
+    } finally {
+        file?.delete()
     }
 }