asp自定义控件实现无刷新上传图片,立即显示缩略图,保存图片缩略图

1、 自定义控件实现无刷新上传图片,立即显示缩略图,保存图片缩略图自定义控件实现无刷新上传图片,立即显示缩略图,保存图片缩略图如图:点击浏览,选择图片之后,右面显示图片 第一步:创建CtFileUpLoad.ascx复制代码 代码如下: iframe src=/WebParts/FileUpLoad.aspx? width=240px height=22px frameborder=0 scrolling=no function CallLoaded() ; 复制代码 代码如下:using System; using System.Collections; using System.Configu

2、ration; using System.Data; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Drawing; public partial class WebParts_CtFileUpLoad : System.Web.UI.UserControl publi

3、c bool AutoFileName get object ob = ViewStateClientID + AutoFileName; if (ob = null) ob = true; return (bool)ob; set ViewStateClientID + AutoFileName = value; public string UpLoadPath get object ob = ViewStateClientID + UpLoadPath; if (ob = null) ob = UPLOADFILES; return ob.ToString(); set ViewState

4、ClientID + UpLoadPath = value; public string OnLoaded get object ob = ViewStateClientID + OnLoaded; if (ob = null) ob = ; return ob.ToString(); set ViewStateClientID + OnLoaded = value; public string SupportExtension get object ob = ViewStateClientID + SupportExtension; if (ob = null) ob = gif|png|j

5、peg|jpg; return ob.ToString(); set ViewStateClientID + SupportExtension = value.Replace(., ); public bool ShowImg get object ob = ViewStateClientID + ShowImg; if (ob = null) ob = true; return (bool)ob; set if (bool)value) dvImg.Styledisplay = block; else dvImg.Styledisplay = none; public string File

6、Name get return tbFileName.Text; protected string ParsValue = ; protected void Page_Load(object sender, EventArgs e) ParsValue = AutoFileName= + AutoFileName.ToString() + &SupportExtension= + SupportExtension + &UpLoadPath= + UpLoadPath + &ID= + ClientID; 第二步: 创建FileUpLoad.aspx 复制代码 代码如下: !DOCTYPE h

7、tml PUBLIC -/W3C/DTD XHTML 1.0 Transitional/EN /TR/xhtml1/ function upload(ob) var expStr=/.*()$/i; if(!expStr.test(ob.value) alert(上传文件类型有误。n(支持文件类型：); else var btUp=document.getElementById(); btUp.click(); 复制代码 代码如下:using System; using System.Collections; using System.Configuration; using Sy

8、stem.Data; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Drawing; using System.IO; public partial class WebParts_FileUpLoad : System.Web.UI.Page protected str

9、ing SupportExtension = ; protected string UpLoadPath = ; protected bool AutoFileName; protected string ParentID = ; protected void Page_Load(object sender, EventArgs e) SupportExtension = Request.QueryStringSupportExtension; UpLoadPath = Request.QueryStringUpLoadPath; AutoFileName = bool.Parse(Reque

10、st.QueryStringAutoFileName.ToString(); ParentID = Request.QueryStringID.ToString(); protected void btUp_Click(object sender, EventArgs e) Boolean fileOK = false; if (FileUpload1.HasFile) String fileExtension = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower(); String allowedExtensions = Su

11、pportExtension.Split(new string | , StringSplitOptions.RemoveEmptyEntries); for (int i = 0; i allowedExtensions.Length; i+) if (fileExtension = . + allowedExtensionsi) fileOK = true; if (fileOK) string path = ; string name = ; string sPath = ; if (AutoFileName) name = DateTime.Now.Ticks.ToString() +

12、 System.IO.Path.GetExtension(FileUpload1.FileName).ToLower(); else name = FileUpload1.FileName; sPath = Request.PhysicalApplicationPath + + UpLoadPath + ; path = sPath + name; /图片地址 string fileName = name; /文件名 string fileName_s = s_ + name; /缩略图文件名称 try /FileInfo file = new FileInfo(name); / string

13、 fileContentType = FileUpload1.PostedFile.ContentType; /string name = FileUpload1.PostedFile.FileName;/客户端文件路径 /string fileName_sy = sy_ + file.Name; /水印图文件名称(文字) /string fileName_syp = syp_ + file.Name;/水印图文件名称(图片) /string webFilePath = Server.MapPath(UpLoadPath + + fileName); /string webFilePath_s

14、 = Server.MapPath(UpLoadPath + + fileName_s); string webFilePath = sPath + fileName;/服务器端文件路径 string webFilePath_s = sPath + fileName_s;/服务器端缩略图路径 if (!File.Exists(webFilePath) if (FileUpload1.PostedFile.ContentLength 800 | image.Height 600) MakeThumbnail(webFilePath, webFilePath_s, 800, 600, W);/生成

15、缩略图的方法 else MakeThumbnail(webFilePath, webFilePath_s, 300, 230, W);/生成缩略图的方法 image.Dispose(); / AddShuiYinWord(webFilePath, webFilePath_sy); /保存水印文字图片 / AddShuiYinPic(webFilePath, webFilePath_syp, webFilePath_sypf);/保存添加水印图片之后的图片 /MakeThumbnail(webFilePath, webFilePath_s, 400, 300, W);/生成缩略图的方法 Page

16、.RegisterClientScriptBlock(succcess, alert(上传成功); parent.document.getElementById( + ParentID + _ + tbFileName + ).value= + fileName_s + ; ); catch (Exception ex) Page.RegisterClientScriptBlock(err, alert(提示：文件上传失败，失败原因： + ex.Message + );); else Page.RegisterClientScriptBlock(err, alert(提示：图片不能大于2M);

17、); else this.Page.RegisterClientScriptBlock(err, alert(图片重复);); catch (System.Exception err) this.Page.RegisterClientScriptBlock(err, alert( + err.Message + );); try Bitmap bmp = new Bitmap(path); int width = 0, height = 0; int dvalue = 200; if (bmp.Width dvalue & bmp.Height bmp.Height) width = dval

18、ue; height = dvalue * (bmp.Width / bmp.Height); else height = dvalue; width = dvalue * (bmp.Height / bmp.Width); this.Page.RegisterClientScriptBlock(show, parent.VarValue= + UpLoadPath + / + fileName_s + ; + parent. + ParentID + CallLoaded(); + .getElementById( + ParentID + _ + dvImg + ).innerHTML=

19、+ + ; ); bmp.Dispose(); catch finally /*判断该文件是否存在,如果存在,则删除图片 if (File.Exists(path) /*删除用户客户端上传的图片,服务器上只保存缩略之后的图片 File.Delete(path); else this.Page.RegisterClientScriptBlock(err, alert(error);); / / 生成缩略图 / / 源图路径（物理路径） / 缩略图路径（物理路径） / 缩略图宽度 / 缩略图高度 / 生成缩略图的方式 public void MakeThumbnail(string origina

20、lImagePath, string thumbnailPath, int width, int height, string mode) System.Drawing.Image originalImage = System.Drawing.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) ca

21、se 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

22、 / (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 System.

23、Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight); /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.SmoothingMo

24、de.HighQuality; /清空画布并以透明背景色填充 g.Clear(System.Drawing.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 System.Drawing.Rectangle(0, 0, towidth, toheight), new System.Drawing.Rectangle(x, y, ow, oh), System.Drawing.GraphicsUnit.Pixel); try /以jpg格式保存缩略图 bitmap.Save(thumbnailPa

25、th, System.Drawing.Imaging.ImageFormat.Jpeg); catch (System.Exception e) throw e; finally originalImage.Dispose(); bitmap.Dispose(); g.Dispose(); / / 在图片上增加文字水印 / / 原服务器图片路径 / 生成的带文字水印的图片路径 protected void AddShuiYinWord(string Path, string Path_sy) string addText = ; System.Drawing.Image image = System.Drawing.Image.FromFile(Path); System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image); g.DrawImage(image, 0, 0, image.Width, image.Height); System.Drawing.Font f = new System.Drawing.Font(Verdana, 16); System.Drawing.Brush b = new System.Drawing.Soli