VB automatically changes the variable to lowercase.

Today, I checked the variable C in my control. Originally, I defined all C as uppercase, And Then VB automatically changed to lowercase C. ProgramBut it is always uncomfortable.
I first found all the definition statements related to C, followed by spaces at the end, and then saved them all. In this way, the files are stored in uppercase C, and the project is opened, but VB is converted to lowercase C immediately.
I will search the entire directory and search for "C" and "c. "These two items, and found that when passing parameters (byref C ...) dim B as string, C as string. These two methods are not the "dim C as" Form I first looked.
After all these changes are corrected, Open VB again. The result is still the same. I thought it was the impact of previous versions, So I compiled the control again, but the result is still the same.
Later, I had to use exclusion, first exclude the Interface Class in the control system, and then exclude the module class. At this time, I found that VB would not automatically convert my C to C, next, we will sort out the module class in two parts, and finally find the culprit is to copy a segment of others. CodeIn, other people's definitions do not need to describe byval or byref, but directly (C as string ). So my search is invalid.
After correction, it will be OK.