WPF九宫格图片自定义皮肤（新博速读2.0）

一直想要做成有搜狗输入法、QQ输入法那样的可以自定义皮肤的软件。找了很久终于找到了，不过找到的解决方案有些问题，经过修改之后就可以按照图片原本的大小显示啦~

在我两个晚上的研究下，研究好几种方法，最后在网上找到了一个好方法，但是有些问题，我修改了下，终于实现新版新博速读的皮肤功能啦。

软件官网：http://leaful.com/weibopopup

public class NineGridsBorder : Border // 九宫格Border  {    public BitmapImage BackgroundImage    {      get { return (BitmapImage)GetValue(BackgroundImageProperty); }      set { SetValue(BackgroundImageProperty, value); }    }    public static readonly DependencyProperty BackgroundImageProperty =      DependencyProperty.Register("BackgroundImage", typeof(BitmapImage), typeof(NineGridsBorder),       new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.AffectsRender));    public Thickness SizingMargins    {      get { return (Thickness)GetValue(SizingMarginsProperty); }      set { SetValue(SizingMarginsProperty, value); }    }    public static readonly DependencyProperty SizingMarginsProperty =      DependencyProperty.Register("SizingMargins", typeof(Thickness), typeof(NineGridsBorder),       new FrameworkPropertyMetadata(new Thickness(), FrameworkPropertyMetadataOptions.AffectsRender));    protected override void OnRender(DrawingContext dc)    {      var img = BackgroundImage;      if (img == null) return;      var renderRect = new Rect(0, 0, RenderSize.Width, RenderSize.Height);      if (SizingMargins == new Thickness())      {        dc.DrawRectangle(new ImageBrush(img), null, renderRect);        return;      }      var sms = SizingMargins;      double[] verticalgl = {0d, sms.Left, renderRect.Width - sms.Right, renderRect.Width};      double[] horizontalgl = {0d, sms.Top, renderRect.Height - sms.Bottom, renderRect.Height};      var gls = new GuidelineSet(verticalgl, horizontalgl);      gls.Freeze();      dc.PushGuidelineSet(gls);      double[] vx = { 0d, sms.Left / img.PixelWidth, (img.PixelWidth - sms.Right) / img.PixelWidth, 1d };      double[] vy = { 0d, sms.Top / img.PixelHeight, (img.PixelHeight - sms.Bottom) / img.PixelHeight, 1d };      double[] x = { renderRect.Left, renderRect.Left + sms.Left, renderRect.Right - sms.Right, renderRect.Right };      double[] y = { renderRect.Top, renderRect.Top + sms.Top, renderRect.Bottom - sms.Bottom, renderRect.Bottom };      for (var i = 0; i < 3; ++i)      {        for (var j = 0; j < 3; ++j)        {          var brush = new ImageBrush(img)          {            Viewbox = new Rect(vx[j], vy[i], Math.Max(0D, (vx[j + 1] - vx[j])),              Math.Max(0D, (vy[i + 1] - vy[i])))          };          dc.DrawRectangle(brush, null, new Rect(x[j], y[i], Math.Max(0D, (x[j + 1] - x[j])), Math.Max(0D, (y[i + 1] - y[i]))));        }      }      dc.Pop();    }  }

izingMargin和ContentMargin