WPF中如何控制每个像素透明度

Question

想达到的效果是。两张图片重叠。鼠标在第一张上面滑动，鼠标滑过的地方变为透明能看到下面的一张。请问如何去动态的修改图片单个像素的透明度啊。。先谢谢啦。

Answer 1

lz的要求确实很麻烦，不好弄，先搜索一些Brush方面的资料吧，我感觉得用Polyline + ImageBrush这类的东西来做，具体我也没试过。

Answer 2

问一个问题。pictureBox透明问题怎么解决呀。我现在像素问题解决了，可是像素透明了以后 pictureBox这个控件不透明。。郁闷。

Answer 3

<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="810" Width="972">
    <Canvas Name="canvas1" Background="#FF3E3D3D">
        <Image Canvas.Left="90" Canvas.Top="12" Name="image1" Stretch="Fill"  MouseLeftButtonDown="image1_MouseLeftButtonDown" SnapsToDevicePixels="True" MouseMove="image1_MouseMove" MouseLeftButtonUp="image1_MouseLeftButtonUp" MouseLeave="image1_MouseLeave" />
    </Canvas>
</Window>using System;
using System.Collections.Generic;
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;namespace WpfApp
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.image1.Source = wb;
        }
        WriteableBitmap wb = new WriteableBitmap(new BitmapImage(new Uri(@"C:\Users\Administrator\Desktop\WpfApp\WpfApp\sunset.png")));        bool f = false;
        private void image1_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            f = true;
        }
        private static byte[] _colorArray = new byte[16] { 245, 255, 255, 0, 245, 255, 255, 0, 245, 255, 255, 0, 245, 255, 255, 0 };        private void image1_MouseMove(object sender, MouseEventArgs e)
        {
            if (f)
            {
                                Point pt = e.GetPosition(this.image1);                if (pt.X > wb.Width)
                {
                    return;
                }                if (pt.Y > wb.Height)
                {
                    return;
                }
                wb.WritePixels(new Int32Rect((int)pt.X, (int)pt.Y, 2, 2), _colorArray, 8, 0);
                this.image1.Source = wb;
            }
        }        private void image1_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            f = false;
        }        private void image1_MouseLeave(object sender, MouseEventArgs e)
        {
            f = false;
        }
    }
}