C# WPF 制作9宫格，出现：间隔、裂痕，问题

Jave.Lin 2013-11-07 05:33:18

如题：

源码项目：Scale9GridTestingProject.rar

我的：Scale9Image类源码：



using System;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Media;

using System.Windows.Media.Imaging;



namespace Scale9GridTestingProject

{

    public class Scale9Image : Image

    {

        private ImageSource _imgSrc;

        private Int32Rect? _rect;

        private ImageSource[] _s9gFragment;

        private bool _bootScale9;

        private BitmapImage _bi;



        public Scale9Image()

            : this(null, null, true)

        {

        }



        public Scale9Image(ImageSource imgSrc, Int32Rect? rect, bool bootScale9)

            : base()

        {

            _imgSrc = imgSrc;

            _rect = rect;

            _bootScale9 = bootScale9;



            Source = _imgSrc;

        }



        public ImageSource imgSrc 

        {

            get { return _imgSrc; }

            set

            {

                if (_imgSrc != value)

                {

                    _imgSrc = value;

                    Source = _imgSrc;

                    InvalidateVisual();

                }

            }

        }

        public Int32Rect? rect 

        { 

            get { return _rect; }

            set

            {

                if (_rect != value)

                {

                    _rect = value;

                    InvalidateVisual();

                }

            }

        }

        public bool bootScale9 

        { 

            get { return _bootScale9; }

            set

            {

                if (_bootScale9 != value)

                {

                    _bootScale9 = value;

                    InvalidateVisual();

                }

            }

        }



        protected override void OnRender(DrawingContext dc)

        {

            if (_bootScale9 && _rect != null && _rect != Int32Rect.Empty)

            {

                OnS9GDraw(dc);

                return;

            }

            

            base.OnRender(dc);

        }



        private void OnS9GDraw(DrawingContext dc)

        {

            if(Source == null) return;



            DrawFragment(dc);

        }



        private void DrawFragment(DrawingContext dc)

        {

            Int32Rect r = rect.Value;

            if (_s9gFragment == null)

            {

                Uri uri = new Uri(Source.ToString(), UriKind.RelativeOrAbsolute);

                _bi = new BitmapImage(uri);

                _s9gFragment = GetS9GImageSource(_bi, r);

            }

            ImageSource[] images = _s9gFragment;

            Rect drawRect = new Rect(new Point(), new Size(r.X, r.Y));

            double right = _bi.PixelWidth - (r.X + r.Width);

            double bottom = _bi.PixelHeight - (r.Y + r.Height);

            double drawWidth = ActualWidth - r.X - right;

            double drawHeight = ActualHeight - r.Y - bottom;

            drawWidth = drawWidth < 0 ? 1 : drawWidth;

            drawHeight = drawHeight < 0 ? 1 : drawHeight;



            // draw actualSize with Green color, why ActualWidth and ActualHeigth is incorrect(in runtimes see it)?

            dc.DrawRectangle(Brushes.Green, new Pen(Brushes.Blue, 1), new Rect(0, 0, ActualWidth, ActualHeight));

            // draw dpiSize with Red color, why Width and Height is incorrect(in runtimes see it)?

            dc.DrawRectangle(Brushes.Red, new Pen(Brushes.Blue, 1), new Rect(0, 0, Width, Height));



            // tl

            dc.DrawImage(images[0], drawRect);

            // tm

            drawRect.X += drawRect.Width;

            drawRect.Width = drawWidth;

            dc.DrawImage(images[1], drawRect);

            // tr

            drawRect.X += drawRect.Width;

            drawRect.Width = right;

            dc.DrawImage(images[2], drawRect);



            // ml

            drawRect.X = 0;

            drawRect.Y = r.Y;

            drawRect.Width = r.X;

            drawRect.Height = drawHeight;

            dc.DrawImage(images[3], drawRect);

            // mm

            drawRect.X += drawRect.Width;

            drawRect.Width = drawWidth;

            dc.DrawImage(images[4], drawRect);

            // mr

            drawRect.X += drawRect.Width;

            drawRect.Width = right;

            dc.DrawImage(images[5], drawRect);



            // bl

            drawRect.X = 0;

            drawRect.Y = ActualHeight - bottom;

            drawRect.Width = r.X;

            drawRect.Height = bottom;

            dc.DrawImage(images[6], drawRect);

            // bm

            drawRect.X += drawRect.Width;

            drawRect.Width = drawWidth;

            dc.DrawImage(images[7], drawRect);

            // br

            drawRect.X += drawRect.Width;

            drawRect.Width = right;

            dc.DrawImage(images[8], drawRect);



            // after draw done, u can see the gap of between s9gimg fragments, why ?

            // anybody help me~~~~ >_< ~~~~

        }



        public static ImageSource CutImage(BitmapSource source, Int32Rect clipRect)

        {

            ImageSource results = null;

            var stride = clipRect.Width * (source.Format.BitsPerPixel / 8);

            var pixelsCount = clipRect.Width * clipRect.Height;//tileWidth * tileHeight;

            var tileRect = new Int32Rect(0, 0, clipRect.Width, clipRect.Height);



            var pixels = new int[pixelsCount];

            //var copyRect = new Int32Rect(col * tileWidth, row * tileHeight, tileWidth, tileHeight);

            source.CopyPixels(clipRect, pixels, stride, 0);

            var wb = new WriteableBitmap(

                clipRect.Width,

                clipRect.Height,

                source.DpiX,

                source.DpiY,

                source.Format,

                source.Palette);

            wb.Lock();

            wb.WritePixels(tileRect, pixels, stride, 0);

            wb.Unlock();



            results = wb;

            return results;

        }



        public static ImageSource[] GetS9GImageSource(BitmapSource source, Int32Rect clipRect)

        {

            ImageSource[] results = new ImageSource[9];

            Int32Rect rect = Int32Rect.Empty;

            int rightSideWidth = (int)(source.PixelWidth - clipRect.X - clipRect.Width);

            //top-left

            rect.Width = clipRect.X;

            rect.Height = clipRect.Y;

            results[0] = CutImage(source, rect);

            //return results;

            //top-middle

            rect.X += rect.Width;

            rect.Width = clipRect.Width;

            results[1] = CutImage(source, rect);

            //top-right

            rect.X += rect.Width;

            rect.Width = rightSideWidth;

            results[2] = CutImage(source, rect);



            //left side

            rect = Int32Rect.Empty;

            rect.Y = clipRect.Y;

            rect.Width = clipRect.X;

            rect.Height = clipRect.Height;

            results[3] = CutImage(source, rect);



            //middle

            rect.X += rect.Width;

            rect.Width = clipRect.Width;

            results[4] = CutImage(source, rect);



            //right side

            rect.X += rect.Width;

            rect.Width = rightSideWidth;

            results[5] = CutImage(source, rect);

            //bottom-left

            rect = Int32Rect.Empty;

            rect.Y = clipRect.Y + clipRect.Height;

            // rect.X = clipRect.X;

            rect.Height = source.PixelHeight - clipRect.Height - clipRect.Y;

            rect.Width = clipRect.X;

            results[6] = CutImage(source, rect);



            //bottom-middle

            rect.X += rect.Width;

            rect.Width = clipRect.Width;

            results[7] = CutImage(source, rect);

            //bottom-right

            rect.X += rect.Width;

            rect.Width = rightSideWidth;

            results[8] = CutImage(source, rect);

            return results;

        }

    }

}