在.so中加载Xamarin.Android文件

Question

我正试图在C#中将Java类转换为Xamarin.Android。

原始Java类如下所示：

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");
}

我认为这个“原生”方法是.so库中的方法。我说的对吗？

因此，为了在我的Xamarin.Android项目中加载这些库，我尝试这样做：

[DllImport("usb-1.0")]
public static extern int GetUSB();
[DllImport("ftrScanAPI")]
public static extern int GetScanAPI();
[DllImport("ftrScanApiAndroidJni")]
public static extern int GetScanAPIAndroidJNI();

并在我的项目中创建了一个文件夹结构，如：project/lib/arm/files.so

当我运行这个项目时，我会发现很多错误：

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'.

知道我做错什么了吗？

Answer 1

如果您正在使用Visual，并且正在向Xamarin移植一些已经在Android上工作的JNI-Java代码，请执行以下步骤：

1. 将.so文件放在Xamarin项目的"lib“文件夹下，例如：

​

1. 确保将.so文件设置为“构建操作”为“”

- Right click to your .so files -> Properties 

​

​

1. 在C#-Xamarin中，您可以通过以下方式加载库 尝试{ JavaSystem.LoadLibrary("SDL2")；JavaSystem.LoadLibrary("glib-2.0")；JavaSystem.LoadLibrary(“gser-2.0”)；JavaSystem.LoadLibrary("fluidsynth")；JavaSystem.LoadLibrary("sdl_mixer")；JavaSystem.LoadLibrary(“混频器”)；} catch (UnsatisfiedLinkError e) {返回e.Message}；
2. 必须以下列方式声明C#中的本机方法： DllImport("initmixer"，EntryPoint = "Java_sf2Tools_FluidsynthJNI_loadSong")公共静态extern loadSong(IntPtr env，IntPtr thiz，IntPtr songPath，int毫秒)；DllImport("initmixer"，EntryPoint = "Java_sf2Tools_FluidsynthJNI_isPlaying")公共静态extern int isPlaying()；DllImport("initmixer"，EntryPoint = "Java_sf2Tools_FluidsynthJNI_pauseAudio")公共静态extern pauseAudio()；DllImport("initmixer"，Java_sf2Tools_FluidsynthJNI_pauseAudio)公共静态extern en19#()；DllImport(“密混器”，EntryPoint = "Java_sf2Tools_FluidsynthJNI_stopAudio")、DllImport(“密混器”，EntryPoint = "Java_sf2Tools_FluidsynthJNI_setSoundfonts")公共静态extern setSoundfonts(IntPtr env，IntPtr thiz，IntPtr js)；

在"EntryPoint“字段中，必须将函数的名称与C/C++代码(通常为EntryPoint)中的名称完全相同

例如，这里是我的原始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
}

或者检查通常给Android的警告，以知道您的本机函数的全名：

​

​

1. 在C# Xamarin中，有时不能跳过在java中所做的参数，例如: JNIEnv * env或jobject --您应该在这个参数上使用IntPtr作为变量类型。例如，为了调用loadSong函数，我使用了以下参数。

C/C++

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

C# Xamarin

fluidsynth.setSoundfonts(JNIEnv.Handle, System.IntPtr.Zero, new Java.Lang.String(getCFGPathFiltered()).Handle);

• 对于以"j“开头的C++参数(例如: jstring、jint )，您不能在jstring上使用C#字符串--例如，您应该使用：

->新Java.Lang.String("sampleString").Handle -> System.IntPtr

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