Question

我无法获取目录，我正在使用的IDE是使用Kotlin语言的Android Studio，我已经输入了图像目录的确切路径，即“ D：\ Fyp \ app \ src \ main \ res \ drawable \ picture” .jpg”，我已经尝试使用相同的代码在IntelliJ上运行，但效果也很好，但是对于android studio来说，它却无法正常工作...下面是代码...

private fun encoder(): String {
    val bytes = File("D:\\Fyp\\app\\src\\main\\res\\drawable\\picture.jpg").readBytes()
    val base64 = Base64.getEncoder().encodeToString(bytes)
    return base64
}

这些是错误日志...

2019-12-16 20:26:24.415 15322-15322/com.example.fyp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.fyp, PID: 15322
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.fyp/com.example.fyp.MainActivity}: java.io.FileNotFoundException: D:\Fyp\app\src\main\res\drawable\image.jpg: open failed: ENOENT (No such file or directory)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3270)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
    at android.os.Handler.dispatchMessage(Handler.java:107)
    at android.os.Looper.loop(Looper.java:214)
    at android.app.ActivityThread.main(ActivityThread.java:7356)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
 Caused by: java.io.FileNotFoundException: D:\Fyp\app\src\main\res\drawable\image.jpg: open failed: ENOENT (No such file or directory)
    at libcore.io.IoBridge.open(IoBridge.java:496)
    at java.io.FileInputStream.<init>(FileInputStream.java:159)
    at kotlin.io.FilesKt__FileReadWriteKt.readBytes(FileReadWrite.kt:63)
    at com.example.fyp.MainActivity.encoder(MainActivity.kt:62)
    at com.example.fyp.MainActivity.onCreate(MainActivity.kt:57)
    at android.app.Activity.performCreate(Activity.java:7802)
    at android.app.Activity.performCreate(Activity.java:7791)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1299)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3245)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409) 
    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) 
    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016) 
    at android.os.Handler.dispatchMessage(Handler.java:107) 
    at android.os.Looper.loop(Looper.java:214) 
    at android.app.ActivityThread.main(ActivityThread.java:7356) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) 
 Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory)
    at libcore.io.Linux.open(Native Method)
    at libcore.io.ForwardingOs.open(ForwardingOs.java:167)
    at libcore.io.BlockGuardOs.open(BlockGuardOs.java:252)
    at libcore.io.ForwardingOs.open(ForwardingOs.java:167)
    at android.app.ActivityThread$AndroidOs.open(ActivityThread.java:7255)
    at libcore.io.IoBridge.open(IoBridge.java:482)
    at java.io.FileInputStream.<init>(FileInputStream.java:159) 
    at kotlin.io.FilesKt__FileReadWriteKt.readBytes(FileReadWrite.kt:63) 
    at com.example.fyp.MainActivity.encoder(MainActivity.kt:62) 
    at com.example.fyp.MainActivity.onCreate(MainActivity.kt:57) 
    at android.app.Activity.performCreate(Activity.java:7802) 
    at android.app.Activity.performCreate(Activity.java:7791) 
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1299) 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3245) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409) 
    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) 
    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016) 
    at android.os.Handler.dispatchMessage(Handler.java:107) 
    at android.os.Looper.loop(Looper.java:214) 
    at android.app.ActivityThread.main(ActivityThread.java:7356) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

Answer 1

在Android应用程序中使用PC上文件的路径是没有意义的。

此外，资源（项目的res目录中的任何资源）都不是已编译应用程序中的传统文件。您无法将它们作为文件访问，并且从商店安装应用程序后，它们甚至可能甚至不存在于应用程序中（如果根据设备特征将其滤除）。

要在应用程序中包含可以在运行时加载的文件，则需要将它们放在assets目录中，而不要放在res中。如果您还没有assets目录，请在src/main中创建一个目录。然后将文件放入其中。您可以这样阅读：

val bytes = context.assets.open("picture.jpg").use { it.readBytes() }

请注意，使用use包装了readBytes()调用。这是在完成阅读后关闭输入流。否则，您将泄漏输入流。

在File（）上获取目录android studio kotlin的问题

1 个答案: