android - 无法创建 SensorDirectChanel

Question

由于 API 26 SensorDirectChannel 可用于可能更快的采样率。它可以与 MemoryFile 或 HardwareBuffer 一起用作 Buffer。我在尝试创建 channel 时同时收到 IOExceptions。我试过如下:

SensorManager sm = (SensorManager)getSystemService(Service.SENSOR_SERVICE);
MemoryFile memFile = null;
try {
   memFile = new MemoryFile("AccMemoryFile", 1040);
} catch (Exception e) {
   e.printStackTrace();
}

SensorDirectChannel channel = sm.createDirectChannel(memFile);

我收到以下消息:

02-26 15:15:46.477 10323-10323/de.makos.directchaneltest E/AndroidRuntime: FATAL EXCEPTION: main
                                                                       Process: de.makos.directchaneltest, PID: 10323
                                                                       java.lang.RuntimeException: Unable to start activity ComponentInfo{de.makos.directchaneltest/de.makos.directchaneltest.MainActivity}: java.io.UncheckedIOException: java.io.IOException: create MemoryFile direct channel failed -12
                                                                           at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
                                                                           at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
                                                                           at android.app.ActivityThread.-wrap11(Unknown Source:0)
                                                                           at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
                                                                           at android.os.Handler.dispatchMessage(Handler.java:106)
                                                                           at android.os.Looper.loop(Looper.java:164)
                                                                           at android.app.ActivityThread.main(ActivityThread.java:6494)
                                                                           at java.lang.reflect.Method.invoke(Native Method)
                                                                           at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:440)
                                                                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
                                                                        Caused by: java.io.UncheckedIOException: java.io.IOException: create MemoryFile direct channel failed -12
                                                                           at android.hardware.SystemSensorManager.createDirectChannelImpl(SystemSensorManager.java:587)
                                                                           at android.hardware.SensorManager.createDirectChannel(SensorManager.java:904)
                                                                           at de.makos.directchaneltest.MainActivity.onCreate(MainActivity.java:37)
                                                                           at android.app.Activity.performCreate(Activity.java:7044)
                                                                           at android.app.Activity.performCreate(Activity.java:7035)
                                                                           at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
                                                                           at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731)
                                                                           at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856) 
                                                                           at android.app.ActivityThread.-wrap11(Unknown Source:0) 
                                                                           at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589) 
                                                                           at android.os.Handler.dispatchMessage(Handler.java:106) 
                                                                           at android.os.Looper.loop(Looper.java:164) 
                                                                           at android.app.ActivityThread.main(ActivityThread.java:6494) 
                                                                           at java.lang.reflect.Method.invoke(Native Method) 
                                                                           at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:440) 
                                                                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 
                                                                        Caused by: java.io.IOException: create MemoryFile direct channel failed -12
                                                                           at android.hardware.SystemSensorManager.createDirectChannelImpl(SystemSensorManager.java:588)
                                                                           at android.hardware.SensorManager.createDirectChannel(SensorManager.java:904) 
                                                                           at de.makos.directchaneltest.MainActivity.onCreate(MainActivity.java:37) 
                                                                           at android.app.Activity.performCreate(Activity.java:7044) 
                                                                           at android.app.Activity.performCreate(Activity.java:7035) 
                                                                           at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214) 
                                                                           at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731) 
                                                                           at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856) 
                                                                           at android.app.ActivityThread.-wrap11(Unknown Source:0) 
                                                                           at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589) 
                                                                           at android.os.Handler.dispatchMessage(Handler.java:106) 
                                                                           at android.os.Looper.loop(Looper.java:164) 
                                                                           at android.app.ActivityThread.main(ActivityThread.java:6494) 
                                                                           at java.lang.reflect.Method.invoke(Native Method) 
                                                                           at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:440) 
                                                                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

使用 HardwareBuffer 我得到了类似的异常。代码:

HardwareBuffer accHawBuff = HardwareBuffer.create(1040, 1, HardwareBuffer.BLOB, 1, HardwareBuffer.USAGE_SENSOR_DIRECT_DATA);
SensorDirectChannel channel= sm.createDirectChannel(accHawBuff);

异常信息:

02-26 15:27:07.592 10774-10774/de.makos.brakelightdatacollector E/AndroidRuntime: FATAL EXCEPTION: main
                                                                              Process: de.makos.brakelightdatacollector, PID: 10774
                                                                              java.lang.RuntimeException: Unable to start activity ComponentInfo{de.makos.brakelightdatacollector/de.makos.brakelightdatacollector.MainActivity}: java.io.UncheckedIOException: java.io.IOException: create HardwareBuffer direct channel failed -12
                                                                                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
                                                                                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
                                                                                  at android.app.ActivityThread.-wrap11(Unknown Source:0)
                                                                                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
                                                                                  at android.os.Handler.dispatchMessage(Handler.java:106)
                                                                                  at android.os.Looper.loop(Looper.java:164)
                                                                                  at android.app.ActivityThread.main(ActivityThread.java:6494)
                                                                                  at java.lang.reflect.Method.invoke(Native Method)
                                                                                  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:440)
                                                                                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
                                                                               Caused by: java.io.UncheckedIOException: java.io.IOException: create HardwareBuffer direct channel failed -12
                                                                                  at android.hardware.SystemSensorManager.createDirectChannelImpl(SystemSensorManager.java:612)
                                                                                  at android.hardware.SensorManager.createDirectChannel(SensorManager.java:927)
                                                                                  at de.makos.brakelightdatacollector.MesseinheitDirectChanel.registerListener(MesseinheitDirectChanel.java:63)
                                                                                  at de.makos.brakelightdatacollector.MainActivity.onCreate(MainActivity.java:64)
                                                                                  at android.app.Activity.performCreate(Activity.java:7044)
                                                                                  at android.app.Activity.performCreate(Activity.java:7035)
                                                                                  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
                                                                                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731)
                                                                                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856) 
                                                                                  at android.app.ActivityThread.-wrap11(Unknown Source:0) 
                                                                                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589) 
                                                                                  at android.os.Handler.dispatchMessage(Handler.java:106) 
                                                                                  at android.os.Looper.loop(Looper.java:164) 
                                                                                  at android.app.ActivityThread.main(ActivityThread.java:6494) 
                                                                                  at java.lang.reflect.Method.invoke(Native Method) 
                                                                                  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:440) 
                                                                                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 
                                                                               Caused by: java.io.IOException: create HardwareBuffer direct channel failed -12
                                                                                  at android.hardware.SystemSensorManager.createDirectChannelImpl(SystemSensorManager.java:613)
                                                                                  at android.hardware.SensorManager.createDirectChannel(SensorManager.java:927) 
                                                                                  at de.makos.brakelightdatacollector.MesseinheitDirectChanel.registerListener(MesseinheitDirectChanel.java:63) 
                                                                                  at de.makos.brakelightdatacollector.MainActivity.onCreate(MainActivity.java:64) 
                                                                                  at android.app.Activity.performCreate(Activity.java:7044) 
                                                                                  at android.app.Activity.performCreate(Activity.java:7035) 
                                                                                  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214) 
                                                                                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731) 
                                                                                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856) 
                                                                                  at android.app.ActivityThread.-wrap11(Unknown Source:0) 
                                                                                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589) 
                                                                                  at android.os.Handler.dispatchMessage(Handler.java:106) 
                                                                                  at android.os.Looper.loop(Looper.java:164) 
                                                                                  at android.app.ActivityThread.main(ActivityThread.java:6494) 
                                                                                  at java.lang.reflect.Method.invoke(Native Method) 
                                                                                  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:440) 
                                                                                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 

由于没有使用直接 channel 的示例或其他文档，我不确定我是否错过了什么。我在运行 Oreo 8.1 (API 27) 的真实和虚拟设备上进行了尝试。我稍微查看了 native 函数，但找不到原因。我也无法弄清楚 -12 是什么意思。

我希望有人能澄清这一点。提前致谢

Answer 1

兄弟，我认为造成这个问题的原因是你的设备不支持SensorDirectChannel。

我最近遇到了一个类似的问题，我无法通过传递一个 MemoryFile 实例来创建 SensorDirectChannel，它的 Logcat 信息与你得到的信息几乎相同，但我可以通过传递一个 HardwareBuffer 实例来完成它，这很奇怪。在检查了一些文档后，我从 this site 找到了原因。 .

项目 7.3.9 说:

Blockquote

If device implementations include direct sensor support, they:

[C-3-1] MUST correctly declare support of direct channel types and direct report rates level through the isDirectChannelTypeSupported and getHighestDirectReportRateLevel API.

[C-3-2] MUST support at least one of the two sensor direct channel types for all sensors that declare support for sensor direct channel

• TYPE_HARDWARE_BUFFER
• TYPE_MEMORY_FILE
• SHOULD support event reporting through sensor direct channel for primary sensor (non-wakeup variant) of the following types:
• TYPE_ACCELEROMETER
• TYPE_ACCELEROMETER_UNCALIBRATED
• TYPE_GYROSCOPE
• TYPE_GYROSCOPE_UNCALIBRATED
• TYPE_MAGNETIC_FIELD
• TYPE_MAGNETIC_FIELD_UNCALIBRATED

因此，很明显，传感器供应商必须让他们的传感器支持 TYPE_HARDWARE_BUFFER SensorDirectChannel 或 TYPE_MEMORY_FILE SensorDirectChannel 或两者，否则您将无法使用它们。

最后，我通过 isDirectChannelTypeSupported 检查了我设备 (Pixel2) 的加速度传感器并得到如下预期结果: resultscreenshot.希望对您有所帮助。

顺便说一句，我的英语不太好。如果让您感到困惑，我们深表歉意。