D3DXCreateTextureFromFileEx()不能用黑色去背景么？解决方案

D3DXCreateTextureFromFileEx()不能用黑色去背景么？

C/C++ code

D3DXCreateTextureFromFileEx(        g_D3DDevice,        "ugp2.png",        0,        0,        0,        0,        D3DFMT_UNKNOWN,        D3DPOOL_MANAGED,        D3DX_DEFAULT,        D3DX_DEFAULT,        D3DCOLOR_XRGB(0,0,0),        &info,        NULL,        &g_Texture);// ...g_D3DDevice->SetRenderState(D3DRS_ALPHATESTENABLE, TRUE); g_D3DDevice->SetRenderState(D3DRS_ALPHAFUNC, D3DCMP_GREATEREQUAL);g_D3DDevice->SetRenderState(D3DRS_ALPHAREF, D3DCOLOR_XRGB(0,0,0));