那些遇到过的问题

在Xamarin.Android中加载.so文件

per*_*zzo 3 c# java mono android xamarin.android

我正在尝试将Xamarin.Android中的Java类转换为C＃。

原始的Java类具有以下内容：

private native boolean OpenDeviceCtx(Object obj);
public native boolean CloseDevice();
public native boolean GetDiodesStatus(byte[] bArr);
public native boolean GetFrame(byte[] bArr);
public native boolean GetImage(int i, byte[] bArr);
public native boolean GetImage2(int i, byte[] bArr);
public native boolean GetImageByVariableDose(int i, byte[] bArr);
public native boolean GetImageSize();
public native boolean GetInterfaces(byte[] bArr);
public native String GetVersionInfo();
public native boolean IsFingerPresent();
public native boolean OpenDevice();
public native boolean OpenDeviceOnInterface(int i);
public native boolean Restore7Bytes(byte[] bArr);
public native boolean RestoreSecret7Bytes(byte[] bArr, byte[] bArr2);
public native boolean Save7Bytes(byte[] bArr);
public native boolean SaveSecret7Bytes(byte[] bArr, byte[] bArr2);
public native boolean SetDiodesStatus(int i, int i2);
public native boolean SetGlobalSyncDir(String str);
public native boolean SetLogOptions(int i, int i2);
public native boolean SetNewAuthorizationCode(byte[] bArr);
public native boolean SetOptions(int i, int i2);

static {
    System.loadLibrary("usb-1.0");
    System.loadLibrary("ftrScanAPI");
    System.loadLibrary("ftrScanApiAndroidJni");
}
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我认为这种“本机”方法是.so库中的方法。我对么？

因此，为了将这些库加载到我的Xamarin.Android项目中，我尝试执行以下操作：

[DllImport("usb-1.0")]
public static extern int GetUSB();
[DllImport("ftrScanAPI")]
public static extern int GetScanAPI();
[DllImport("ftrScanApiAndroidJni")]
public static extern int GetScanAPIAndroidJNI();
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并在我的项目中创建了一个文件夹结构，例如：project / lib / arm / files.so

当我运行项目时，我会遇到很多错误：

DllImport attempting to load: 'usb-1.0'.
DllImport error loading library '/storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0" not found'.
DllImport error loading library '/storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0.so" not found'.
DllImport error loading library '/system/lib/libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//system/lib/libusb-1.0" not found'.
DllImport error loading library '/system/lib/libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//system/lib/libusb-1.0.so" not found'.
DllImport error loading library 'libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0" not found'.
DllImport error loading library 'libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0.so" not found'.
DllImport error loading library 'usb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/usb-1.0" not found'.
DllImport error loading library '/storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0" not found'.
DllImport error loading library '/storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0.so" not found'.
DllImport error loading library '/system/lib/libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//system/lib/libusb-1.0" not found'.
DllImport error loading library '/system/lib/libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//system/lib/libusb-1.0.so" not found'.
DllImport error loading library 'libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0" not found'.
DllImport error loading library 'libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0.so" not found'.
DllImport error loading library 'libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0" not found'.
DllImport unable to load library 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0" not found'.
DllImport attempting to load: 'usb-1.0'.
DllImport error loading library '/storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0" not found'.
DllImport error loading library '/storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0.so" not found'.
DllImport error loading library '/system/lib/libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//system/lib/libusb-1.0" not found'.
DllImport error loading library '/system/lib/libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//system/lib/libusb-1.0.so" not found'.
DllImport error loading library 'libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0" not found'.
DllImport error loading library 'libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0.so" not found'.
DllImport error loading library 'usb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/usb-1.0" not found'.
DllImport error loading library '/storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0" not found'.
DllImport error loading library '/storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//storage/emulated/0/Android/data/RDScanFingerprint.RDScanFingerprint/files/.__override__/libusb-1.0.so" not found'.
DllImport error loading library '/system/lib/libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//system/lib/libusb-1.0" not found'.
DllImport error loading library '/system/lib/libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm//system/lib/libusb-1.0.so" not found'.
DllImport error loading library 'libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0" not found'.
DllImport error loading library 'libusb-1.0.so': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0.so" not found'.
DllImport error loading library 'libusb-1.0': 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0" not found'.
DllImport unable to load library 'dlopen failed: library "/data/app/RDScanFingerprint.RDScanFingerprint-1/lib/arm/libusb-1.0" not found'.
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知道我在做什么错吗？

Led*_*ine 5

如果您使用的是Visual Studio，并且要将某些已经在Android上运行的JNI-Java代码移植到Xamarin，请按照以下步骤操作：

  1. 将您的.so文件放在Xamarin项目上的“ lib”文件夹下，例如： 在此处输入图片说明

  2. 确保将.so文件设置为“ Build Action”为“ Android Native Library”

    • 右键单击您的.so文件->属性 在此处输入图片说明 在此处输入图片说明

  3. 在C＃-Xamarin中，您可以通过以下方式加载您的库

    try
{
    JavaSystem.LoadLibrary("SDL2");
    JavaSystem.LoadLibrary("glib-2.0");
    JavaSystem.LoadLibrary("gthread-2.0");
    JavaSystem.LoadLibrary("fluidsynth");
    JavaSystem.LoadLibrary("sdl_mixer");
    JavaSystem.LoadLibrary("initmixer");
}
catch (UnsatisfiedLinkError e)
{
    return e.Message;
}
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  4. 必须使用以下方式声明C＃中的本机方法：

    [DllImport("initmixer", EntryPoint = "Java_sf2Tools_FluidsynthJNI_loadSong")]
public static extern int loadSong(IntPtr env, IntPtr thiz, IntPtr songPath, int miliseconds);
[DllImport("initmixer", EntryPoint = "Java_sf2Tools_FluidsynthJNI_isPlaying")]
public static extern int isPlaying();
[DllImport("initmixer", EntryPoint = "Java_sf2Tools_FluidsynthJNI_pauseAudio")]
public static extern void pauseAudio();
[DllImport("initmixer", EntryPoint = "Java_sf2Tools_FluidsynthJNI_resumeAudio")]
public static extern void resumeAudio();
[DllImport("initmixer", EntryPoint = "Java_sf2Tools_FluidsynthJNI_stopAudio")]
public static extern void stopAudio();
[DllImport("initmixer", EntryPoint = "Java_sf2Tools_FluidsynthJNI_setSoundfonts")]
public static extern void setSoundfonts(IntPtr env, IntPtr thiz, IntPtr js);
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在“ EntryPoint”字段上，您必须正确输入函数名称，它们的名称通常与C / C ++代码中的Java_your_package_name_YourClassName_YourMethodName相同。

例如，这是我的原始C ++代码：

void Java_sf2Tools_FluidsynthJNI_setSoundfonts(JNIEnv * env, jobject this, jstring js)
{
    //Some code
}
void Java_sf2Tools_FluidsynthJNI_pauseAudio(JNIEnv * env, jobject this)
{
    //Some code
}
void Java_sf2Tools_FluidsynthJNI_resumeAudio(JNIEnv * env, jobject this)
{
    //Some code
}
int Java_sf2Tools_FluidsynthJNI_isPlaying(JNIEnv * env, jobject this)
{
    //Some code
}
void Java_sf2Tools_FluidsynthJNI_stopAudio(JNIEnv * env, jobject this)
{
    //Some code
}

int Java_sf2Tools_FluidsynthJNI_loadSong(JNIEnv * env, jobject this, jstring songPath)
{
    //Some code
}
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或者，也许可以检查通常使Android Studio知道本机功能全名的警告：

在此处输入图片说明

  1. 在C＃Xamarin中，有时您不能跳过在Java中执行的参数，例如：JNIEnv * env，或对此进行工作拒绝，您应在此参数上将IntPtr用作变量类型。例如，调用loadSong函数时，我使用了以下参数。

C / C ++

void Java_sf2Tools_FluidsynthJNI_setSoundfonts(JNIEnv * env, jobject this, jstring js)
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C＃Xamarin

fluidsynth.setSoundfonts(JNIEnv.Handle, System.IntPtr.Zero, new Java.Lang.String(getCFGPathFiltered()).Handle);
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  • 注意以“ j”开头的C ++参数，例如：jstring，jint，例如，不能在jstring上使用C＃字符串，应使用：

jstring->新的Java.Lang.String（“ sampleString”）。Handle-> System.IntPtr

jint->新的Java.Lang.Integer（4）.Handle-> System.IntPtr

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