尝试使用 Rectangle.Intersect 方法 [ ^ ]。

好吧，如果你想检测两个球之间的碰撞，那么条件应该是（经谢尔盖的批准:-D）。

Well, if you want to detect collision between two balls then the condition should be (subject to Sergey''s approval :-D).

(XC0-XC1)*(XC0-XC1)+(YC0-YC1)*(YC0-YC1) <= R1*R1+R2*R2+2*R1*R2

这两个中心之间的距离小于（或等于）它们的半径之和

That is distance between the two centers is less than (or equal) to sum of their radii

我认为***的解决方案结合了上面的两条评论，看起来应该是这样的：

I think the best solution combines both comments above, and should look something like this:

if( ! Ball1.IntersectsWith(Ball2))
{
   return false;
}

double Ball1CenterX = (Ball1.Right - Ball1.Width)/2;
double Ball2CenterX = (Ball2.Right - Ball2.Width)/2;
double Ball1CenterY = (Ball1.Bottom - Ball1.Height)/2;
//double Ball2CenterY = (Ball1.Bottom - Ball1.Height)/2;    // oops! (Ball1 ?) [MTH: fixed below]
double Ball2CenterY = (Ball2.Bottom - Ball2.Height)/2;

double Ball1Radious = Ball1.Width/2;
double Ball2Radious = Ball2.Width/2;

return (Ball2CenterX - Ball1CenterX)^2 + (Ball2CenterY - Ball1CenterY)^2 
         <= 
        (Ball1Radious + Ball2Radious)^2;   // [MTH: fixed. don't "times 2"]