SharpDX创建SwapChain1触发AccessViolationException问题排查

问题描述 #

尝试在SharpDX中创建SwapChain1，实现代码如下：

SwapChainDescription1 desc = new()
{
    Width = toSetSize.Value.Width,
    Height = toSetSize.Value.Height,
    Format = Format.R8G8B8A8_UNorm,
    Stereo = false,
    SampleDescription = new SampleDescription(1, 0),
    Usage = Usage.BackBuffer | Usage.RenderTargetOutput,
    BufferCount = 1,
    Scaling = Scaling.Stretch,
    SwapEffect = SwapEffect.Discard
};

SwapChainFullScreenDescription scd = new SwapChainFullScreenDescription()
{
    RefreshRate = new Rational(60, 1),
    Scaling = DisplayModeScaling.Stretched,
    Windowed = false
};

using (var dxgiDevice2 = device.QueryInterface<SharpDX.DXGI.Device2>())
using (var dxgiAdapter = dxgiDevice2.Adapter)
using (var dxgiFactory2 = dxgiAdapter.GetParent<SharpDX.DXGI.Factory2>())
{
    res = new SwapChain1(dxgiAdapter.GetParent<SharpDX.DXGI.Factory2>(), device, Window.Handle, ref desc, scd);
    return res;
}

运行时触发AccessViolationException，提示“Attempted to read or write corrupted memory”。调整desc和scd参数无效，排查发现factory.NativePointer曾为IntPtr.Zero并更新代码，开启原生调试后得到报错：

Exception called at 0x759CE292 in Demo.exe: Microsoft C++ Exception: _com_error at location 0x0297C5B8.
Exception called at 0x6BA81D22 (dxgi.dll) in Demo.exe: 0xC0000005: Access violation at position 0x000000B8.

德语原文：

Ausnahme ausgelöst bei 0x759CE292 in Demo.exe: Microsoft C++-Ausnahme: _com_error bei Speicherort 0x0297C5B8.
Ausnahme ausgelöst bei 0x6BA81D22 (dxgi.dll) in Demo.exe: 0xC0000005: Zugriffsverletzung beim Lesen an Position 0x000000B8.

问题根源与修复方法 #

1. 核心问题：重复获取Factory2导致的COM对象生命周期异常 #

代码中已在using块内获取了dxgiFactory2实例，但创建SwapChain1时又调用dxgiAdapter.GetParent<SharpDX.DXGI.Factory2>()重新获取Factory实例。这种重复获取会导致新实例未被SharpDX的托管机制正确管理，其内部COM对象可能提前释放，进而引发内存访问错误。

2. 修复代码 #

直接使用using块内已创建的dxgiFactory2实例，避免重复获取：

SwapChainDescription1 desc = new()
{
    Width = toSetSize.Value.Width,
    Height = toSetSize.Value.Height,
    Format = Format.R8G8B8A8_UNorm,
    Stereo = false,
    SampleDescription = new SampleDescription(1, 0),
    Usage = Usage.BackBuffer | Usage.RenderTargetOutput,
    BufferCount = 1,
    Scaling = Scaling.Stretch,
    SwapEffect = SwapEffect.Discard
};

SwapChainFullScreenDescription scd = new SwapChainFullScreenDescription()
{
    RefreshRate = new Rational(60, 1),
    Scaling = DisplayModeScaling.Stretched,
    Windowed = false
};

using (var dxgiDevice2 = device.QueryInterface<SharpDX.DXGI.Device2>())
using (var dxgiAdapter = dxgiDevice2.Adapter)
using (var dxgiFactory2 = dxgiAdapter.GetParent<SharpDX.DXGI.Factory2>())
{
    // 使用已托管的dxgiFactory2实例
    res = new SwapChain1(dxgiFactory2, device, Window.Handle, ref desc, scd);
    return res;
}

3. 额外验证点 #

• 确认device是有效的D3D设备实例，且版本支持DXGI Device2接口
• 检查Window.Handle为有效窗口句柄，窗口已完成初始化
• 若仍报错，尝试将SwapEffect改为SwapEffect.FlipSequential，部分硬件对Discard模式兼容性有限

内容的提问来源于stack exchange，提问作者user19815545