这里两个变量都是整数，因此您执行整数除法：

Here both variables are integers so you are performing integer division:

activeCircleRadius / numSteps

整数除法的结果是整数。结果被截断。

The result of integer division is an integer. The result is truncated.

要解决此问题，请将一个（或两个）变量的类型更改为 float ：

To fix the problem, change the type of one (or both) variables to a float:

float stepSize = 0.0f;
float activeCircleRadius = 10;

或者在分部表达式中添加一个转换为float：

Or add a cast to float in the division expression:

stepSize = (float)activeCircleRadius / numSteps;