函数内的常量字符串

Question

来自Mricrosoft XNA Education Catalog 的片段：

    /// <summary>
    /// Draws the control, using SpriteBatch and SpriteFont.
    /// </summary>
    protected override void Draw()
    {
        const string message = "Hello, World!\n" +
                               "\n" +
                               "I'm an XNA Framework GraphicsDevice,\n" +
                               "running inside a WinForms application.\n" +
                               "\n" +
                               "This text is drawn using SpriteBatch,\n" +
                               "with a SpriteFont that was loaded\n" +
                               "through the ContentManager.\n" +
                               "\n" +
                               "The pane to my right contains a\n" +
                               "spinning 3D triangle.";

        GraphicsDevice.Clear(Color.CornflowerBlue);

        spriteBatch.Begin();
        spriteBatch.DrawString(font, message, new Vector2(23, 23), Color.White);
        spriteBatch.End();
    }

每秒调用Draw 60 次。在绘图内分配消息是否有任何性能开销？这和我将它移动到静态帮助器类一样吗？据我记得，成本表达式是由 C# 编译器计算的。这里const修饰符改变了什么？

Answer 1

const 仅被评估一次。将其移至静态变量中不会获得任何好处。

Answer 2

不，它全部为您优化。