Can someone help me to figure out why GPU instancing failed after building in Unity?

Here's what I have in C# code:

Code (CSharp):

1.        Graphics.DrawMeshInstanced(meshToDraw, 0, material, renderMatrices, renderMatrices.Length, null, ShadowCastingMode.Off, true, 0, null, LightProbeUsage.Off);

In shader, I add some code like this:

Code (CSharp):

1.             #pragma multi_compile_instancing

And I already used the instance in shader.
In my graphics settings, I set the Instancing variants to be Keep All.
But after building, I can't see any mesh to be rendering.

 

I've already accomplished it.We also have to add your shader with instance to the Always Included Shaders.But it's better to use RenderDoc.