C#图片压缩类winform
using System;
using System.Collections.Generic;
using
System.Text;
using System.Drawing;
using System.Drawing.Imaging;
using
System.IO;
using System.Windows.Forms;
namespace EU.EUClass
{
class ImgGDI
{
public
ImgGDI()
{
//构造函数
}
///
/// Bitmap转换byte[]数组
///
///
///
public byte[] Bmptobyte(Bitmap
bmp)
{
MemoryStream ms = new MemoryStream();
bmp.Save(ms, ImageFormat.Jpeg);
ms.Flush();
byte[]
buffer = ms.GetBuffer();
ms.Close();
return
buffer;
}
///
/// byte[]数组转换Bitmap
///
///
///
public Bitmap bytetobmp(byte[]
buffer)
{
MemoryStream ms = new MemoryStream();
ms.Write(buffer, 0, buffer.Length);
Bitmap bmp = new Bitmap(ms);
ms.Close();
return
bmp;
}
///
/// 返回默认图片
///
///
public
Bitmap getInstance()
{
Bitmap bmp = DefaultPic();
return bmp;
}
///
/// 选取本地图片
///
///
///
public Bitmap LocalIMG(string
IMG)
{
FileStream fs = new FileStream(IMG, FileMode.Open);
Bitmap bmp = new Bitmap(fs);
fs.Close();
return bmp;
}
///
/// 返回流状态图片
///
///
///
public Bitmap ImgFromBase64(string
Img)
{
Bitmap bmp;
byte[] buffer =
Convert.FromBase64String(Img);
if
(buffer.Length > 0)
{
MemoryStream ms = new
MemoryStream();
ms.Write(buffer, 0, buffer.Length);
bmp = new Bitmap(ms);
ms.Close();
return bmp;
}
else
{
bmp =
DefaultPic() ;
return
bmp;
}
}
///
/// 默认图片
///
///
private Bitmap DefaultPic()
{
FileStream fs = new
FileStream(Application.StartupPath + @"\Goodr.jpg", FileMode.Open);
Bitmap bmp = new Bitmap(fs);
fs.Close();
return bmp;
}
///
/// GDI压缩图片
///
/// 传入参数Bitmap
///
public byte[] ImageGdi(Bitmap
bmp)
{
Bitmap xbmp = new Bitmap(bmp);
MemoryStream ms = new MemoryStream();
xbmp.Save(ms, ImageFormat.Jpeg);
byte[] buffer;
ms.Flush();
if (ms.Length >
95000)
{
//buffer = ms.GetBuffer();
double new_width = 0;
double new_height = 0;
Image m_src_image = Image.FromStream(ms);
if (m_src_image.Width >=
m_src_image.Height)
{
new_width = 1024;
new_height = new_width * m_src_image.Height /
(double)m_src_image.Width;
}
else if
(m_src_image.Height >= m_src_image.Width)
{
new_height = 768;
new_width = new_height *
m_src_image.Width / (double)m_src_image.Height;
}
Bitmap bbmp = new Bitmap((int)new_width, (int)new_height,
m_src_image.PixelFormat);
Graphics m_graphics = Graphics.FromImage(bbmp);
m_graphics.SmoothingMode =
System.Drawing.Drawing2D.SmoothingMode.HighQuality;
m_graphics.InterpolationMode =
System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
m_graphics.DrawImage(m_src_image, 0,
0, bbmp.Width, bbmp.Height);
ms = new MemoryStream();
bbmp.Save(ms, ImageFormat.Jpeg);
buffer = ms.GetBuffer();
ms.Close();
return buffer;
}
else
{
buffer = ms.GetBuffer();
ms.Close();
return buffer;
}
}
}
}
