怎样同时压缩图片的大小和长宽?
这个只。我想设置压缩后的图片的长宽,该怎么设置呢?
EncoderParameters encParams = new EncoderParameters( 1 );
// 65%品质的JPEG格式图片
encParams.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 65L);
ImageCodecInfo codeInfo = null;
ImageCodecInfo[] codeInfos = ImageCodecInfo.GetImageEncoders();
foreach(ImageCodecInfo info in codeInfos)
{
if(info.MimeType.Equals("image/jpeg"))
{
codeInfo = info;
break;
}
}
// targetImage为目标图片
if(codeInfo != null)
{
System.Drawing.Image img = System.Drawing.Image.FromStream(file1.PostedFile.InputStream,true);
string s = Server.MapPath( "/bin")+"1.jpg" ;
img.Save(s , codeInfo, encParams);
}
public void pic_zero(string sourcepath,string aimpath,int scale)
{
string originalFilename =sourcepath;
//生成的高质量图片名称
string strGoodFile =aimpath;
//从文件取得图片对象 System.Drawing.Image image = System.Drawing.Image.FromFile(originalFilename);
int iImgWidth = image.Width;
int iImgHeight = image.Height;
int iScale = (iImgWidth / scale)>(iImgHeight/scale) ? (iImgWidth / scale) : (iImgHeight / scale);
//取得图片大小
System.Drawing.Size size = new Size(image.Width / iScale , image.Height / iScale);
//新建一个bmp图片 System.Drawing.Image bitmap = new System.Drawing.Bitmap(size.Width,size.Height);
//新建一个画板
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
//设置高质量插值法 g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//设置高质量,低速度呈现平滑程度
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//清空一下画布
g.Clear(Color.Blue);
//在指定位置画图
g.DrawImage(image, new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height),
new System.Drawing.Rectangle(0, 0, image.Width,image.Height),
System.Drawing.GraphicsUnit.Pixel);
//保存高清晰度的缩略图 bitmap.Save(strGoodFile, System.Drawing.Imaging.ImageFormat.Jpeg);
g.Dispose();
}
asp.net 2.0中判断上传的图片是否符合规格
在asp.net 2.0中,在上传图片时,有时往往要判断用户上传的图片是否符合指定规格,如果不符合规格,
则不予以上传,那么可以用以下的代码片段进行判断。
首先在web.config文件中设置图片上传的限制尺寸,比如
之后,在页面获得web.config文件里预先设定的尺寸
if (Page.IsPostBack)
{
height = Convert.ToInt32(
ConfigurationManager.AppSettings.Get("RequiredHeight"));
width = Convert.ToInt32(
ConfigurationManager.AppSettings.Get("RequiredWidth"));
}
之后在“上传”按钮的事件代码中如下编写
if (Page.IsValid)
{
if (FileUpload1.HasFile)
{
string extension = Path.GetExtension(FileUpload1.PostedFile.FileName);
switch (extension.ToLower())
{
case ".gif":
case "jpg":
try
{
//如果符合尺寸
if (ValidateFileDimensions())
{
string fileName = Path.GetFileName(FileUpload1.PostedFile.FileName);
string saveAsName = Path.Combine(Server.MapPath("~/Uploads/"), fileName); FileUpload1.PostedFile.SaveAs(saveAsName);
lblSucces.Visible = true;
}
else
{
valInvalidDimensions.IsValid = false;
valInvalidDimensions.ErrorMessage = String.Format(valInvalidDimensions.ErrorMessage, height, width); }
}
catch
{
// Unable to read the file dimensions. The uploaded file is probably not an image. valInvalidFile.IsValid = false;
} break;
default: // The uploaded file has an incorrect extension
valInvalidFile.IsValid = false;
break;
}
}
}
public bool ValidateFileDimensions()
{
using (System.Drawing.Image myImage = System.Drawing.Image.FromStream(FileUpload1.PostedFile.InputStream))
{
return (myImage.Height == height && myImage.Width == width);
}
}
要留意其中ValidateFileDimensions()中完成了判断尺寸的过程了
最后,页面放一些验证控件