C＃代码优化

Question

who could be faster ? and why ?

1:

Point point = new Point(25,25);   //any numbers..
Point point2 = new Point(20,95);  //any numbers..

Graphics g = CreateGraphics();
g.DrawLine(point,point2);

OR

2:

Graphics g = CreateGraphics();
g.DrawLine(new Point(25,25),new Point(20,95));

Answer 1

None of them, since both snippets will compile to the same MSIL code representation.

Besides, this is a micro-optimization, which you should avoid before actually knowing that it is the bottleneck.

Answer 2

两者之间都没有真正的区别，只是可读性下降（特别是在JITing之后）。

Answer 3

Micro Optimization, huh? One notable playwright says code readability is more important than micro optimizations , and I agree.

Answer 4

两者都不是更快，最快的就是避免完全在“渲染”路径中分配这些点并提前创建它们的点。

Answer 5

2 might be faster because you're not creating intermediate pointers to the object before passing it to g.DrawLine; however, if that's the only place you use point and point2 then the compiler will likely optimize so the binary is the same anyway.

Answer 6

It all depends on what else you're doing.

If you're doing almost nothing else (which I doubt) then this is the "bottleneck".

If this is the "bottleneck" then you still don't know what's dominant:

• two "new"s and associated constructors, destructors, and garbage collection.

• actually rendering lines.

The second is probably unavoidable, but the first is only there for style reasons.

You can find out by profiling or this simple method .

Or you can avoid the whole question with:

g.DrawLine(25,25,20,95);