WPF的性能问题

Sun, 22 Feb 2009 18:27:00 GMT

最�q�因为工作的原因�Q�修改了一些同事写的Silverlight�E�序。知道Silverlight是WPF的一个子集，倒是很想看看WPF能有怎样一个效率表现。想起以前做�q�的一个“质炚w��”的Demo.于是��抄起VS2008��例子改写成WPF�?br />:�Q�完整项目文�?

1   public partial class Window1 : Window
2    {
3        private Ellipse[] circles;
4        public Window1()
5        {
6            InitializeComponent();
7            InitCirlces(100);
8        }
9
10        private void InitCirlces(int nCircle)
11        {
12            circles =new Ellipse[nCircle];
13            for(int i=0; i<nCircle; ++i)
14            {
15                Ellipse c = new Ellipse();
16                c.Height = 3;
17                c.Width = 3;
18                c.Stroke = new SolidColorBrush(Colors.Black);
19                c.Visibility= Visibility.Visible;
20                c.RenderTransform = new TranslateTransform();
21                Canvas.SetTop(c, 0);
22                Canvas.SetLeft(c, 0);
23                board.Children.Add(c);
24                circles[i]=c;
25            }
26
27
28        }
29        private void Window_MouseMove(object sender, MouseEventArgs e)
30        {
31            Point p=e.GetPosition(this);
32            var firstC = circles[0];
33            SetPos(firstC, p);
34            for (int i = 1; i < circles.Length; ++i )
35            {
36                Ellipse c = circles[i];
37                Point curP = GetPos(c);
38                Vector v = p - curP;
39                double len = v.Length;
40                if (len > 5)
41                {
42                    v.Normalize();
43                    v = v * (len - 5);
44                    p = curP + v;
45                    SetPos(c, p);
46                }else
47                {
48                    p = curP;
49                }
50            }
51
52        }
53
54        private void SetPos(UIElement ue, Point p)
55        {
56            TranslateTransform tr = ue.RenderTransform as TranslateTransform;
57            tr.X = p.X;
58            tr.Y = p.Y;
59            //Canvas.SetTop(ue, p.Y);
60            //Canvas.SetLeft(ue, p.X);
61        }
62
63        private Point GetPos(UIElement ue)
64        {
65            TranslateTransform tr = ue.RenderTransform as TranslateTransform;
66            return new Point(tr.X, tr.Y);
67            //return new Point(Canvas.GetLeft(ue), Canvas.GetTop(ue));
68        }
69
70    }

实际�q�行�l�果很不理想。cpu占用率很高。通过性能分析工具发现�Q�大多数旉��都浪费在了TranslateTransform.Set_X和TranslateTransform.Set_Y上�?br />刚刚��ȝ��WPF不��半天�Q�不敢确认效率低是WPF本��n的问题，�q�是自己选择的实现方式的问题�?/p>

如果有好的徏议，��L��a��?br />:�Q�完整项目文�?

莫千�?/a> 2009-02-23 02:27 发表评论

strnins

Tue, 21 Mar 2006 03:09:00 GMT

bool strnins( char * dst, size_t n, const char * src, int pos);
/* ***********************************************
有以下几�U�情况要考虑
** dst ==NULL
** src == NULL
** pos��过��N��
** 希望对pos��数时�Q�能按python的方式解�?
** 如果dst�I�间不够�?只插入src的一部分.
************************************************* */

莫千�?/a> 2006-03-21 11:09 发表评论

toUpper

Tue, 21 Mar 2006 01:22:00 GMT

void toUpper( char * s) {
     if ( ! s) {
       return ;
    }
     while ( * s) {
        if ( ( * s >= ' a ' ) && ( * s <= ' z ' ) ) {
         * s += ' A ' - ' a ' ;
       }
        ++ s;
    }
}

莫千�?/a> 2006-03-21 09:22 发表评论

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WPF的性能问题

strnins

toUpper