图片批量缩放

Posted 2020-10-31 agchuanqi

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{

private void Form1_Load(object sender, EventArgs e)
{

}

public Form1()
{
InitializeComponent();

ListFiles(new DirectoryInfo("f:/nvyi"));

}

public Image pictureProcess(Image sourceImage, int targetWidth, int targetHeight)
{
int width;//图片最终的宽
int height;//图片最终的高
try
{
System.Drawing.Imaging.ImageFormat format = sourceImage.RawFormat;
Bitmap targetPicture = new Bitmap(targetWidth, targetHeight);
Graphics g = Graphics.FromImage(targetPicture);

//计算缩放图片的大小
if (sourceImage.Width > targetWidth && sourceImage.Height <= targetHeight)
{
width = targetWidth;
height = (width * sourceImage.Height) / sourceImage.Width;
}
else if (sourceImage.Width <= targetWidth && sourceImage.Height > targetHeight)
{
height = targetHeight;
width = (height * sourceImage.Width) / sourceImage.Height;
}
else if (sourceImage.Width <= targetWidth && sourceImage.Height <= targetHeight)
{
width = sourceImage.Width;
height = sourceImage.Height;
}
else
{
width = targetWidth;
height = (width * sourceImage.Height) / sourceImage.Width;
if (height > targetHeight)
{
height = targetHeight;
width = (height * sourceImage.Width) / sourceImage.Height;
}
}
g.DrawImage(sourceImage, (targetWidth - width) / 2, (targetHeight - height) / 2, width, height);
sourceImage.Dispose();

return targetPicture;
}
catch (Exception ex)
{

}
return null;
}

public void modifyToPng(string sd, string sf)
{
Image srcImage = Image.FromFile(sf);
int resW = (int)(srcImage.Width *0.8);
int resH = (int)(srcImage.Height*0.8);
srcImage = this.pictureProcess(srcImage, resW, resH);

Bitmap resultImage = new Bitmap(resW, resH);
Graphics g = Graphics.FromImage(resultImage);
g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighSpeed;
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g.DrawImage(srcImage, new Rectangle(0, 0, resW, resH), new Rectangle(0, 0, srcImage.Width, srcImage.Height), GraphicsUnit.Pixel);

 

resultImage.Save(sf.Substring(0, sf.LastIndexOf(".")) + ".png", System.Drawing.Imaging.ImageFormat.Png);
}

public void ListFiles(FileSystemInfo info)
{
if (!info.Exists) return;

DirectoryInfo dir = info as DirectoryInfo;
//不是目录
if (dir == null) return;

FileSystemInfo[] files = dir.GetFileSystemInfos();
for (int i = 0; i < files.Length; i++)
{
FileInfo file = files[i] as FileInfo;
//是文件
if (file != null)
{
//Console.WriteLine(file.FullName + "\t " + file.Length);
if (file.FullName.Substring(file.FullName.LastIndexOf(".")) == ".png")
//此处为显示JPG格式，不加IF可遍历所有格式的文件
{
//this.list1.Items.Add(file);
//MessageBox.Show(file.FullName.Substring(file.FullName.LastIndexOf(".")));
modifyToPng(file.DirectoryName, file.FullName);
}
}
//对于子目录，进行递归调用
else
{
ListFiles(files[i]);
}

}

}
}
}