No 74 · 以不同的透明度显示图像

 

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;using System.Drawing.Drawing2D;namespace Ex13_18{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private Bitmap SourceBitmap;        private Bitmap MyBitmap;        private void button2_Click(object sender, EventArgs e)        {            //打开图像文件            OpenFileDialog openFileDialog = new OpenFileDialog();            openFileDialog.Filter = "图像文件(JPeg, Gif, Bmp, etc.)|*.jpg;*.jpeg;*.gif;*.bmp;*.tif; *.tiff; *.png| JPeg 图像文件(*.jpg;*.jpeg)|*.jpg;*.jpeg |GIF 图像文件(*.gif)|*.gif |BMP图像文件(*.bmp)|*.bmp|Tiff图像文件(*.tif;*.tiff)|*.tif;*.tiff|Png图像文件(*.png)| *.png |所有文件(*.*)|*.*";            if (openFileDialog.ShowDialog() == DialogResult.OK)            {                //得到原始大小的图像                SourceBitmap = new Bitmap(openFileDialog.FileName);                //得到缩放后的图像                MyBitmap = new Bitmap(SourceBitmap, this.pictureBox1.Width, this.pictureBox1.Height);                this.pictureBox1.Image = MyBitmap;            }        }        private void button1_Click(object sender, EventArgs e)        {            //以不同的透明度显示图像                  Graphics g = this.panel1.CreateGraphics();            g.SmoothingMode = SmoothingMode.AntiAlias;            TextureBrush MyBrush = new TextureBrush(MyBitmap);            g.FillRectangle(MyBrush, this.panel1.ClientRectangle);            for (int i = 0; i < 255; i++)            {//由透明变为不透明                g.FillRectangle(new SolidBrush(Color.FromArgb(i,Color.DarkSlateGray)), this.panel1.ClientRectangle);                System.Threading.Thread.Sleep(100);            }           }    }}