diff --git a/example/Vulkan/VKCommandBuffer.h b/example/Vulkan/VKCommandBuffer.h
index 8149fbb4..46620635 100644
--- a/example/Vulkan/VKCommandBuffer.h
+++ b/example/Vulkan/VKCommandBuffer.h
@@ -23,6 +23,8 @@ public:
     CommandBuffer(VkDevice dev,VkCommandPool cp,VkCommandBuffer cb);
     ~CommandBuffer();
 
+    operator VkCommandBuffer(){return cmd_buf;}
+
     void SetRenderArea(const VkRect2D &ra){render_area=ra;}
     void SetClearColor(float r,float g,float b,float a=1.0f)
     {
diff --git a/example/Vulkan/VKDevice.cpp b/example/Vulkan/VKDevice.cpp
index 56193ac0..2f3ea391 100644
--- a/example/Vulkan/VKDevice.cpp
+++ b/example/Vulkan/VKDevice.cpp
@@ -62,6 +62,14 @@ Device::Device(DeviceAttribute *da)
     attr=da;
     current_framebuffer=0;
     image_acquired_semaphore=this->CreateSem();
+
+    present.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
+    present.pNext = nullptr;
+    present.swapchainCount = 1;
+    present.pSwapchains = &attr->swap_chain;
+    present.pWaitSemaphores = nullptr;
+    present.waitSemaphoreCount = 0;
+    present.pResults = nullptr;
 }
 Device::~Device()
 {
@@ -225,4 +233,47 @@ bool Device::AcquireNextImage()
 {
     return(vkAcquireNextImageKHR(attr->device,attr->swap_chain,UINT64_MAX,*image_acquired_semaphore,VK_NULL_HANDLE,&current_framebuffer)==VK_SUCCESS);
 }
+
+bool Device::QueueSubmit(CommandBuffer *buf,Fence *fence)
+{
+    if(!buf||!fence)
+        return(false);
+
+    VkPipelineStageFlags pipe_stage_flags = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
+    VkSubmitInfo submit_info[1] = {};
+
+    VkSemaphore sem=*image_acquired_semaphore;
+    VkCommandBuffer cmd_bufs=*buf;
+
+    submit_info[0].pNext = nullptr;
+    submit_info[0].sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
+    submit_info[0].waitSemaphoreCount = 1;
+    submit_info[0].pWaitSemaphores = &sem;
+    submit_info[0].pWaitDstStageMask = &pipe_stage_flags;
+    submit_info[0].commandBufferCount = 1;
+    submit_info[0].pCommandBuffers = &cmd_bufs;
+    submit_info[0].signalSemaphoreCount = 0;
+    submit_info[0].pSignalSemaphores = nullptr;
+
+    return(vkQueueSubmit(attr->graphics_queue, 1, submit_info, *fence)==VK_SUCCESS);
+}
+
+bool Device::Wait(Fence *f,bool wait_all,uint64_t time_out)
+{
+    VkResult res;
+    VkFence fence=*f;
+
+    do {
+        res = vkWaitForFences(attr->device, 1, &fence, wait_all, time_out);
+    } while (res == VK_TIMEOUT);
+
+    return(true);
+}
+
+bool Device::QueuePresent()
+{
+    present.pImageIndices = &current_framebuffer;
+
+    return(vkQueuePresentKHR(attr->present_queue, &present)==VK_SUCCESS);
+}
 VK_NAMESPACE_END
diff --git a/example/Vulkan/VKDevice.h b/example/Vulkan/VKDevice.h
index 1dc40ad7..76fef9bc 100644
--- a/example/Vulkan/VKDevice.h
+++ b/example/Vulkan/VKDevice.h
@@ -22,6 +22,8 @@ class Device
     Semaphore *image_acquired_semaphore;
     uint32_t current_framebuffer;
 
+    VkPresentInfoKHR present;
+
 private:
 
     friend Device *CreateRenderDevice(VkInstance,const PhysicalDevice *,Window *);
@@ -68,6 +70,12 @@ public:
     Semaphore *CreateSem();
 
     bool AcquireNextImage();
+
+    bool QueueSubmit(CommandBuffer *,Fence *);
+
+    bool Wait(Fence *,bool wait_all=VK_TRUE,uint64_t time_out=HGL_NANO_SEC_PER_SEC*0.1);
+
+    bool QueuePresent();
 };//class Device
 VK_NAMESPACE_END
 #endif//HGL_GRAPH_RENDER_SURFACE_INCLUDE
diff --git a/example/Vulkan/VKFence.h b/example/Vulkan/VKFence.h
index e9960056..a5028517 100644
--- a/example/Vulkan/VKFence.h
+++ b/example/Vulkan/VKFence.h
@@ -21,6 +21,8 @@ private:
 public:
 
     ~Fence();
+
+    operator VkFence(){return fence;}
 };//class Fence
 VK_NAMESPACE_END
 #endif//HGL_VULKAN_GRAPH_FENCE_INCLUDE