Can't send uniform values to shader

I'm trying to set some uniform values for my shader, but I can only get a texture I already used before(slot 0), and all matrix were filled with 0.

Here is a part of my code.

glUseProgram(VSSMTestShaderProgram);
glUniform1i(glGetUniformLocation(VSSMTestShaderProgram, "depthMap"), 10);
glUniform1i(glGetUniformLocation(VSSMTestShaderProgram, "depth2Map"), 11);
transformLoc = glGetUniformLocation(VSSMTestShaderProgram, "transformToScreenSpace");
glUniformMatrix4fv(transformLoc, 1, GL_FALSE, glm::value_ptr(view_trans));
glm::mat4 shadowProj = glm::ortho(-10.0f, 10.0f, -10.0f, 10.0f, 0.01f, 30.0f);
glm::mat4 shadowTransform = shadowProj * glm::lookAt(glm::vec3(5.0,5.0,5.0), glm::vec3(0.0, 0.0, 0.0), glm::vec3(0.0, 1.0, 0.0));
transformLoc = glGetUniformLocation(VSSMTestShaderProgram, "transformToLightSpace");
glUniformMatrix4fv(transformLoc, 1, GL_FALSE, glm::value_ptr(shadowTransform));
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

here is the shader code

//shader for VSSM shadows
const char* vertexVSSMTest = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"out vec4 LightSpaceCoord;\n"
"uniform mat4 transformToScreenSpace;\n"
"uniform mat4 transformToLightSpace;\n"
"void main()\n"
"{\n"
"   gl_Position = transformToScreenSpace * vec4(aPos.x, aPos.y, aPos.z, 1.0f);\n"
"	LightSpaceCoord = transformToLightSpace * vec4(aPos.x, aPos.y, aPos.z, 1.0f);\n"
"}
//shader for VSSM shadows
const char* vertexVSSMTest = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"out vec4 LightSpaceCoord;\n"
"uniform mat4 transformToScreenSpace;\n"
"uniform mat4 transformToLightSpace;\n"
"void main()\n"
"{\n"
"   gl_Position = transformToScreenSpace * vec4(aPos.x, aPos.y, aPos.z, 1.0f);\n"
"	LightSpaceCoord = transformToLightSpace * vec4(aPos.x, aPos.y, aPos.z, 1.0f);\n"
"}\0";
const char* fragVSSMTest = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec4 LightSpaceCoord;\n"
"uniform sampler2D depthMap;\n"
"uniform sampler2D depth2Map;\n"
"void main()\n"
"{\n"//vec2(LightSpaceCoord.x/2+0.5, LightSpaceCoord.y/2+0.5)
"	float lightDepth = texture(depthMap, vec2(0.1, 0.1)).r;\n"
"	if(lightDepth<LightSpaceCoord.z){\n"
"		FragColor = vec4(lightDepth, lightDepth, lightDepth, 1.0);\n"
"	}else{\n"
"		FragColor = gl_FragColor;\n"
"	}\n"
"}\n\0";
";
const char* fragVSSMTest = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec4 LightSpaceCoord;\n"
"uniform sampler2D depthMap;\n"
"uniform sampler2D depth2Map;\n"
"void main()\n"
"{\n"//vec2(LightSpaceCoord.x/2+0.5, LightSpaceCoord.y/2+0.5)
"	float lightDepth = texture(depthMap, vec2(0.1, 0.1)).r;\n"
"	if(lightDepth<LightSpaceCoord.z){\n"
"		FragColor = vec4(lightDepth, lightDepth, lightDepth, 1.0);\n"
"	}else{\n"
"		FragColor = gl_FragColor;\n"
"	}\n"
"}\n
//shader for VSSM shadows
const char* vertexVSSMTest = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"out vec4 LightSpaceCoord;\n"
"uniform mat4 transformToScreenSpace;\n"
"uniform mat4 transformToLightSpace;\n"
"void main()\n"
"{\n"
"   gl_Position = transformToScreenSpace * vec4(aPos.x, aPos.y, aPos.z, 1.0f);\n"
"	LightSpaceCoord = transformToLightSpace * vec4(aPos.x, aPos.y, aPos.z, 1.0f);\n"
"}\0";
const char* fragVSSMTest = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec4 LightSpaceCoord;\n"
"uniform sampler2D depthMap;\n"
"uniform sampler2D depth2Map;\n"
"void main()\n"
"{\n"//vec2(LightSpaceCoord.x/2+0.5, LightSpaceCoord.y/2+0.5)
"	float lightDepth = texture(depthMap, vec2(0.1, 0.1)).r;\n"
"	if(lightDepth<LightSpaceCoord.z){\n"
"		FragColor = vec4(lightDepth, lightDepth, lightDepth, 1.0);\n"
"	}else{\n"
"		FragColor = gl_FragColor;\n"
"	}\n"
"}\n\0";
";

the matrix is set as:

and texture is also set incorrectly:

Based on the code you have posted it doesn't seem that you have done anything wrong. That means something is probably wrong somewhere else. An obvious place to check would be to make sure you are calling glActiveTexture(GL_TEXTUREn) where n is the slot before binding your texture and calling your draw function. But there could be any of many things going wrong elsewhere in your code, as openGL can be very sensitive to wrong order calls and such.

I would strongly recommend checking out this tutorial if you haven't already: https://learnopengl.com/Advanced-Lighting/Shadows/Shadow-Mapping. Especially to look at and replicate the sample code.

I would also strongly recommend abstracting away some of those openGL functions to separate methods and testing each method incrementally. If you can get the methods to do what you want them to, then you don't have to worry about those methods causing the problems in the future. Right now you are just directly calling a series of openGL functions which makes it difficult to determine where exactly the problem is occuring.

You can't use gl_FragColor values in shader code.