WPF WriteableBitmap类直接操作像素点

还是话不多说，直接上码：

1.新建WpfApp应用程序

2.MainWindow.xaml文件代码如下：

3.MainWindow.xaml.cs文件代码如下：

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Drawing;
using System.Drawing.Drawing2D;

namespace WpfApp1
{
    /// 

    /// Interaction logic for MainWindow.xaml
    /// 
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        public void Button_Click(object sender, RoutedEventArgs e)
        {

            WriteableBitmap wb = new WriteableBitmap((int)imgGrid.ActualWidth, (int)imgGrid.ActualHeight, 96, 96, PixelFormats.Pbgra32, null);

            wb.Lock();

            Bitmap backBitmap = new Bitmap((int)imgGrid.ActualWidth, (int)imgGrid.ActualHeight, wb.BackBufferStride, System.Drawing.Imaging.PixelFormat.Format32bppArgb, wb.BackBuffer);

            Int32Rect rect = new Int32Rect(0, 0, (int)imgGrid.ActualWidth, (int)imgGrid.ActualHeight);

            byte[] pixels = new byte[(int)imgGrid.ActualWidth * (int)imgGrid.ActualHeight * wb.Format.BitsPerPixel / 8];

            Random rand = new Random();

            for (int y = 0; y < wb.PixelHeight; y++)
            {
                for (int x = 0; x < wb.PixelWidth; x++)
                {
                    int alpha = 0;
                    int red = 0;
                    int green = 0;
                    int blue = 0;

                    if ((x % 5 == 0) || (y % 7 == 0))
                    {
                        red = (int)((double)y / wb.PixelHeight * 255);
                        green = rand.Next(100, 255);
                        blue = (int)((double)x / wb.PixelWidth * 255);
                        alpha = 255;
                    }
                    else
                    {
                        red = (int)((double)x / wb.PixelWidth * 255);
                        green = rand.Next(100, 255);
                        blue = (int)((double)y / wb.PixelHeight * 255);
                        alpha = 50;
                    }

                    int pixeloffset = (x + y * wb.PixelWidth) * wb.Format.BitsPerPixel / 8;
                    pixels[pixeloffset] = (byte)blue;
                    pixels[pixeloffset + 1] = (byte)green;
                    pixels[pixeloffset + 2] = (byte)red;
                    pixels[pixeloffset + 3] = (byte)alpha;
                }

                int stride = (wb.PixelWidth * wb.Format.BitsPerPixel) / 8;

                wb.WritePixels(rect, pixels, stride, 0);
            }

            wb.Unlock();

            backBitmap.Dispose();
            backBitmap = null;

            img.Source = wb;
        }
    }
}

　　效果如下：