如何转换图片文件 如何将分辨率高的图片转化成分辨率低的图片,比如将1024*768的变成640*480的 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 drawing!!!!在ASP.NET中上传图片并生成缩略图,可以参照下列代码:private void btnUploadPicture_Click(object sender, System.EventArgs e) { //检查上传文件的格式是否有效 if(this.UploadFile.PostedFile.ContentType.ToLower().IndexOf("image") < 0) { Response.Write("上传图片格式无效!"); return; } //生成原图 Byte[] oFileByte = new byte[this.UploadFile.PostedFile.ContentLength]; System.IO.Stream oStream = this.UploadFile.PostedFile.InputStream; System.Drawing.Image oImage = System.Drawing.Image.FromStream(oStream); int oWidth = oImage.Width; //原图宽度 int oHeight = oImage.Height; //原图高度 int tWidth = 100; //设置缩略图初始宽度 int tHeight = 100; //设置缩略图初始高度 //按比例计算出缩略图的宽度和高度 if(oWidth >= oHeight) { tHeight = (int)Math.Floor(Convert.ToDouble(oHeight) * (Convert.ToDouble(tWidth) / Convert.ToDouble(oWidth))); } else { tWidth = (int)Math.Floor(Convert.ToDouble(oWidth) * (Convert.ToDouble(tHeight) / Convert.ToDouble(oHeight))); } //生成缩略原图 Bitmap tImage = new Bitmap(tWidth,tHeight); Graphics g = Graphics.FromImage(tImage); g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; //设置高质量插值法 g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;//设置高质量,低速度呈现平滑程度 g.Clear(Color.Transparent); //清空画布并以透明背景色填充 g.DrawImage(oImage,new Rectangle(0,0,tWidth,tHeight),new Rectangle(0,0,oWidth,oHeight),GraphicsUnit.Pixel); string oFullName = Server.MapPath(".") + "/" + "o" + DateTime.Now.ToShortDateString().Replace("-","") + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + ".jpg"; //保存原图的物理路径string tFullName = Server.MapPath(".") + "/" + "t" + DateTime.Now.ToShortDateString().Replace("-","") + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + ".jpg"; //保存缩略图的物理路径 try { //以JPG格式保存图片 oImage.Save(oFullName,System.Drawing.Imaging.ImageFormat.Jpeg); tImage.Save(tFullName,System.Drawing.Imaging.ImageFormat.Jpeg);}catch(Exception ex) { throw ex; } finally { //释放资源 oImage.Dispose();g.Dispose(); tImage.Dispose(); } } 建议你去看下电子科技大的 韩江译的《gdi+图形程序设计》 点击gridview排序,不起作用 关于c# ArrayList的问题 datagridview显示数据 哪位朋友有可供练习的项目啊 用了dialogresult,messagebox.show之后如何不关闭窗体? C++ BYTE * 对应C#什么类型?? SqlCommandBuilder 请问.net2.0中的SmtpMail在哪个名字空间下? 如何在listview中鼠标右键编辑数据 如何去掉字符串中间的空格? 超难度!如何模仿ACCESS的关系视图功能 基于SQL SERVER数据库的.NET程序发布问题?详情请进
在ASP.NET中上传图片并生成缩略图,可以参照下列代码:private void btnUploadPicture_Click(object sender, System.EventArgs e)
{
//检查上传文件的格式是否有效
if(this.UploadFile.PostedFile.ContentType.ToLower().IndexOf("image") < 0)
{
Response.Write("上传图片格式无效!");
return;
}
//生成原图
Byte[] oFileByte = new byte[this.UploadFile.PostedFile.ContentLength];
System.IO.Stream oStream = this.UploadFile.PostedFile.InputStream;
System.Drawing.Image oImage = System.Drawing.Image.FromStream(oStream);
int oWidth = oImage.Width; //原图宽度
int oHeight = oImage.Height; //原图高度
int tWidth = 100; //设置缩略图初始宽度
int tHeight = 100; //设置缩略图初始高度
//按比例计算出缩略图的宽度和高度
if(oWidth >= oHeight)
{
tHeight = (int)Math.Floor(Convert.ToDouble(oHeight) * (Convert.ToDouble(tWidth) / Convert.ToDouble(oWidth)));
}
else
{
tWidth = (int)Math.Floor(Convert.ToDouble(oWidth) * (Convert.ToDouble(tHeight) / Convert.ToDouble(oHeight)));
}
//生成缩略原图
Bitmap tImage = new Bitmap(tWidth,tHeight);
Graphics g = Graphics.FromImage(tImage);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; //设置高质量插值法
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;//设置高质量,低速度呈现平滑程度
g.Clear(Color.Transparent); //清空画布并以透明背景色填充
g.DrawImage(oImage,new Rectangle(0,0,tWidth,tHeight),new Rectangle(0,0,oWidth,oHeight),GraphicsUnit.Pixel);
string oFullName = Server.MapPath(".") + "/" + "o" + DateTime.Now.ToShortDateString().Replace("-","") + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + ".jpg"; //保存原图的物理路径
string tFullName = Server.MapPath(".") + "/" + "t" + DateTime.Now.ToShortDateString().Replace("-","") + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + ".jpg"; //保存缩略图的物理路径
try {
//以JPG格式保存图片
oImage.Save(oFullName,System.Drawing.Imaging.ImageFormat.Jpeg); tImage.Save(tFullName,System.Drawing.Imaging.ImageFormat.Jpeg);
}
catch(Exception ex)
{
throw ex;
}
finally {
//释放资源
oImage.Dispose();
g.Dispose();
tImage.Dispose();
}
}