C#图片按比例缩放实例
本文实例为大家分享了C#图片按比例缩放的具体代码，供大家参考，具体内容如下
工具类代码：
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Drawing;
usingSystem.Drawing.Drawing2D;
usingSystem.Drawing.Imaging;
usingSystem.Linq;
usingSystem.Text;
usingSystem.Threading.Tasks;
namespaceZoomImage.Utils
{
///
///图片缩放
///
publicclassZoomImageUtil
{
///
///图片缩放
///
///图片
///目标宽度，若为0，表示宽度按比例缩放
///目标长度，若为0，表示长度按比例缩放
publicstaticBitmapGetThumbnail(Bitmapbmp,intwidth,intheight)
{
if(width==0)
{
width=height*bmp.Width/bmp.Height;
}
if(height==0)
{
height=width*bmp.Height/bmp.Width;
}
ImageimgSource=bmp;
BitmapoutBmp=newBitmap(width,height);
Graphicsg=Graphics.FromImage(outBmp);
g.Clear(Color.Transparent);
//设置画布的描绘质量
g.CompositingQuality=CompositingQuality.HighQuality;
g.SmoothingMode=SmoothingMode.HighQuality;
g.InterpolationMode=InterpolationMode.HighQualityBicubic;
g.DrawImage(imgSource,newRectangle(0,0,width,height+1),0,0,imgSource.Width,imgSource.Height,GraphicsUnit.Pixel);
g.Dispose();
imgSource.Dispose();
bmp.Dispose();
returnoutBmp;
}
}
}
使用示例：
usingSystem;
usingSystem.Collections.Generic;
usingSystem.ComponentModel;
usingSystem.Data;
usingSystem.Drawing;
usingSystem.IO;
usingSystem.Linq;
usingSystem.Text;
usingSystem.Threading;
usingSystem.Threading.Tasks;
usingSystem.Windows.Forms;
usingZoomImage.Utils;
namespaceZoomImage
{
publicpartialclassForm1:Form
{
publicForm1()
{
InitializeComponent();
}
privatevoidForm1_Load(objectsender,EventArgse)
{
openFileDialog1.Multiselect=true;
}
privatevoidtxtWidth_KeyPress(objectsender,KeyPressEventArgse)
{
if(e.KeyChar!=8&&!Char.IsDigit(e.KeyChar))
{
e.Handled=true;
}
}
privatevoidtxtHeight_KeyPress(objectsender,KeyPressEventArgse)
{
if(e.KeyChar!=8&&!Char.IsDigit(e.KeyChar))
{
e.Handled=true;
}
}
privatevoidbtnSelectImage_Click(objectsender,EventArgse)
{
try
{
if(txtWidth.Text==""&&txtHeight.Text=="")
{
return;
}
if(openFileDialog1.ShowDialog()==DialogResult.OK)
{
Task.Factory.StartNew(()=>
{
stringpath=Path.GetDirectoryName(openFileDialog1.FileNames[0])+"\\NewImage\\";
inti=0;
foreach(stringfileNameinopenFileDialog1.FileNames)
{
Bitmapbmp=ZoomImageUtil.GetThumbnail(newBitmap(fileName),Convert.ToInt32(txtWidth.Text==""?"0":txtWidth.Text),Convert.ToInt32(txtHeight.Text==""?"0":txtHeight.Text));
if(!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
File.Delete(path+Path.GetFileName(fileName));
bmp.Save(path+Path.GetFileName(fileName));
this.Invoke(newInvokeDelegate(()=>
{
lblProgress.Text=string.Format("进度：{1}/{0}",openFileDialog1.FileNames.Length,++i);
}));
Thread.Sleep(1);
}
MessageBox.Show("成功！");
});
}
}
catch(Exceptionex)
{
MessageBox.Show(ex.Message);
}
}
}
///
///跨线程访问控件的委托
///
publicdelegatevoidInvokeDelegate();
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。