如何实现上传图片时的类型格式,大小,像素等等的控制

Question

请问上传图片时如何可以实现控制/检查图片的类型格式,大小,像素呢?谢谢!

Answer 1

用System.Drawing.Image 名空间下的Image类的属性试试

Answer 2

System.Drawing.Image 
这个下面的很多属性的，你看看好了，网上找一下也可以呀

Answer 3

用image好像太复杂了.如果楼主要做的是一个专业的图片上传控件的话,不妨去找第三方组件.

Answer 4

if 上传对象obj.postedfile.contenttype.substring(0,5).tolower="image" then
'是图片
obj.postedfile.contentlength '大小 单位 字节
end if使用这个System.Drawing.Image 可以获取w h

Answer 5

使用System.Drawing.Image 不是要已经上传了文件才操作吗?我想SAVE前就操作了

Answer 6

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
//using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;
using System.Drawing.Imaging;
/// <summary>
/// /**//// <summary> 
/// 生成缩略图 
/// </summary> 
/// <param name="originalImagePath">源图路径（物理路径）</param> 
/// <param name="thumbnailPath">缩略图路径（物理路径）</param> 
/// <param name="width">缩略图宽度</param> 
/// <param name="height">缩略图高度</param> 
/// <param name="mode">生成缩略图的方式</param> 
/// thumbnailimage 的摘要说明
/// </summary>
///     public class thumbnailimage
    {
        public thumbnailimage(string originalImagePath, string thumbnailPath, int width, int height, string mode)
        {            Image originalImage = Image.FromFile(originalImagePath);            int towidth = width;
            int toheight = height;            int x = 0;
            int y = 0;
            int ow = originalImage.Width;
            int oh = originalImage.Height;            switch (mode)
            {
                case "HW"://指定高宽缩放（可能变形）                 
                    break;
                case "W"://指定宽，高按比例                     
                    toheight = originalImage.Height * width / originalImage.Width;
                    break;
                case "H"://指定高，宽按比例 
                    towidth = originalImage.Width * height / originalImage.Height;
                    break;
                case "Cut"://指定高宽裁减（不变形）                 
                    if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                    {
                        oh = originalImage.Height;
                        ow = originalImage.Height * towidth / toheight;
                        y = 0;
                        x = (originalImage.Width - ow) / 2;
                    }
                    else
                    {
                        ow = originalImage.Width;
                        oh = originalImage.Width * height / towidth;
                        x = 0;
                        y = (originalImage.Height - oh) / 2;
                    }
                    break;
                default:
                    break;
            }            //新建一个bmp图片 
            Image bitmap = new System.Drawing.Bitmap(towidth, toheight);            //新建一个画板 
            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;            //清空画布并以透明背景色填充 
            g.Clear(Color.Transparent);            //在指定位置并且按指定大小绘制原图片的指定部分 
            g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
                new Rectangle(x, y, ow, oh),
                GraphicsUnit.Pixel);            try
            {
                //以jpg格式保存缩略图 
                bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
            }
            catch (System.Exception e)
            {
                throw e;
            }
            finally
            {
                originalImage.Dispose();
                bitmap.Dispose();
                g.Dispose();
            }            //
            // TODO: 在此处添加构造函数逻辑
            //
        }
    }

Answer 7

bitMap bmp=new bigMap()
bmp....