winform纹理效果显示图像

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Linq;
using System.Windows.Forms;
using System.Drawing.Imaging;

namespace ImageGrain
{
public partial class Frm_Main : Form
{
Bitmap myBitmap;
public Frm_Main()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
openFileDialog1.Filter = "*.jpg,*.jpeg,*.bmp|*.jpg;*.jpeg;*.bmp"; //设置文件的类型
openFileDialog1.ShowDialog(); //打开文件对话框
Image myImage = System.Drawing.Image.FromFile(openFileDialog1.FileName); //根据文件的路径实例化Image类
myBitmap = new Bitmap(myImage); //实例化Bitmap类
this.BackgroundImage = myBitmap; //显示打开的图片
}

private void button2_Click(object sender, EventArgs e)
{
try
{
Image myImage = System.Drawing.Image.FromFile(openFileDialog1.FileName);//实例化Image类
myBitmap = new Bitmap(myImage); //实例化Bitmap类
Rectangle rect = new Rectangle(0, 0, myBitmap.Width, myBitmap.Height); //实例化Rectangle类
System.Drawing.Imaging.BitmapData bmpData = myBitmap.LockBits(rect,
System.Drawing.Imaging.ImageLockMode.ReadWrite, myBitmap.PixelFormat); //将指定图像锁定到内存中
IntPtr ptr = bmpData.Scan0; //获得图像中第一个像素数据的地址
int bytes = myBitmap.Width * myBitmap.Height * 3; //设置大小
byte[] rgbValues = new byte[bytes];//实例化byte数组
System.Runtime.InteropServices.Marshal.Copy(ptr, rgbValues, 0, bytes); //使用RGB值为声明的rgbValues数组赋值
for (int counter = 0; counter < rgbValues.Length; counter = 3) //初始化大小
rgbValues[counter] = 255;
System.Runtime.InteropServices.Marshal.Copy(rgbValues, 0, ptr, bytes); //使用RGB值为图像的像素点着色
myBitmap.UnlockBits(bmpData); //从内存中解锁图像
this.BackgroundImage = myBitmap; //显示设置后的图片
}
catch { }
}
}
}