Android SharedMemory 是一种进程间通信（IPC）机制，它允许不同进程访问同一块内存区域。在 Android 中，可以使用 Binder 框架来实现 SharedMemory。以下是如何在 Android 中使用 SharedMemory 读写数据的步骤：
#include <android/binder_interface_utils.h> #include <android/log.h> #include <binder/IServiceManager.h> #include <binder/MemoryBase.h> #include <binder/MemoryHeapBase.h> using namespace android; status_t createSharedMemory(size_t size, sp<IMemory> *memory) { sp<IServiceManager> sm = defaultServiceManager(); const String16 name("MySharedMemory"); return sm->addService(String16(name.string()), new SharedMemoryService(size), true); } class SharedMemoryService : public BnMemory { public: SharedMemoryService(size_t size) : mSize(size) { mHeap = new MemoryHeapBase(mSize); } virtual status_t onTransact(uint32_t code, const Parcel &data, Parcel *reply, uint32_t flags = 0) { switch (code) { case GET_SIZE: { reply->writeInt32(mSize); return NO_ERROR; } case READ_DATA: { void *buffer = nullptr; status_t status = mHeap->lock(0, mSize, &buffer, false); if (status == NO_ERROR) { memcpy(buffer, mData.get(), mSize); mHeap->unlock(buffer); reply->writeInt32(mSize); } else { reply->writeInt32(0); } return status; } case WRITE_DATA: { void *buffer = nullptr; status_t status = mHeap->lock(0, mSize, &buffer, true); if (status == NO_ERROR) { memcpy(buffer, data.data(), data.size()); mHeap->unlock(buffer); reply->writeInt32(data.size()); } else { reply->writeInt32(0); } return status; } default: return BBinder::onTransact(code, data, reply, flags); } } private: size_t mSize; sp<MemoryHeapBase> mHeap; Vector<uint8_t> mData; }; #include <android/binder_interface_utils.h> #include <android/log.h> #include <binder/IServiceManager.h> #include <binder/MemoryBase.h> #include <binder/MemoryHeapBase.h> using namespace android; status_t createSharedMemory(size_t size, sp<IMemory> *memory) { sp<IServiceManager> sm = defaultServiceManager(); const String16 name("MySharedMemory"); return sm->addService(String16(name.string()), new SharedMemoryService(size), true); } void readSharedMemoryData(sp<IMemory> memory) { void *buffer = nullptr; status_t status = memory->lock(0, memory->getSize(), &buffer, false); if (status == NO_ERROR) { size_t size = memory->getSize(); memcpy(buffer, mData.get(), size); memory->unlock(buffer); } } void writeSharedMemoryData(sp<IMemory> memory, const uint8_t *data, size_t size) { void *buffer = nullptr; status_t status = memory->lock(0, memory->getSize(), &buffer, true); if (status == NO_ERROR) { memcpy(buffer, data, size); memory->unlock(buffer); } } 注意：这里的示例代码仅供参考，实际使用时需要根据具体需求进行调整。在实际开发中，还需要考虑内存管理、错误处理等方面的问题。
