最近在做相冊功能遇到一個問題,就是加載圖片的時候然後放大,感覺有點卡。圖片可能有點大,所以考慮用縮略圖來實現。
也就是在查詢出來一個相冊圖片 ,一頁顯示幾十張,這幾十張用縮略圖來顯示,看相信情況的時候想QQ相冊樣加載原圖放大拉取圖片相關信息。所用到的技術就是圖片壓縮功能。現在功能已經實現看代碼。
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Imaging;
using System.IO;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
string pathPerc = @"D:\0046620140807150650cin.jpg";
string source = @"G:\0046620140807150650cin.jpg";
if (!File.Exists(pathPerc))
{
File.Create(pathPerc).Close();
}
else
{
File.Delete(pathPerc);
File.Create(pathPerc).Close();
}
getThumImage(source, 18, 3, pathPerc);
}
#region getThumImage
/**/
/// <summary>
/// 生成縮略圖
/// </summary>
/// <param name="sourceFile">原始圖片文件</param>
/// <param name="quality">質量壓縮比</param>
/// <param name="multiple">收縮倍數</param>
/// <param name="outputFile">輸出文件名</param>
/// <returns>成功返回true,失敗則返回false</returns>
public static bool getThumImage(String sourceFile, long quality, int multiple, String outputFile)
{
try
{
long imageQuality = quality;
Bitmap sourceImage = new Bitmap(sourceFile);
ImageCodecInfo myImageCodecInfo = GetEncoderInfo("image/jpeg");
System.Drawing.Imaging.Encoder myEncoder = System.Drawing.Imaging.Encoder.Quality;
EncoderParameters myEncoderParameters = new EncoderParameters(1);
EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, imageQuality);
myEncoderParameters.Param[0] = myEncoderParameter;
float xWidth = sourceImage.Width;
float yWidth = sourceImage.Height;
Bitmap newImage = new Bitmap((int)(xWidth / multiple), (int)(yWidth / multiple));
Graphics g = Graphics.FromImage(newImage);
g.DrawImage(sourceImage, 0, 0, xWidth / multiple, yWidth / multiple);
g.Dispose();
newImage.Save(outputFile, myImageCodecInfo, myEncoderParameters);
return true;
}
catch
{
return false;
}
}
#endregion getThumImage
/**/
/// <summary>
/// 獲取圖片編碼信息
/// </summary>
private static ImageCodecInfo GetEncoderInfo(String mimeType)
{
int j;
ImageCodecInfo[] encoders;
encoders = ImageCodecInfo.GetImageEncoders();
for (j = 0; j < encoders.Length; ++j)
{
if (encoders[j].MimeType == mimeType)
return encoders[j];
}
return null;
}
}
}
11KB
壓縮前的圖片
這樣縮略圖就成功了。