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服务器之家 - 编程语言 - ASP.NET教程 - asp.net 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

asp.net 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

2019-06-30 20:48ASP.NET之家 ASP.NET教程

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: %@ Control Language=C# AutoEventWireup=true CodeFile=CtFileUpLoad.ascx.cs Inherits=WebParts_CtFileUpLoad % table cellpadding=0 cellspacing=0 tr td iframe src=/WebParts/FileUpLoad.

如图:

点击浏览,选择图片之后,右面显示图片

asp.net 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

第一步:

创建CtFileUpLoad.ascx

复制代码代码如下:

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="CtFileUpLoad.ascx.cs" 
Inherits="WebParts_CtFileUpLoad" %> 
<table cellpadding="0" cellspacing="0"> 
<tr> 
<td> 
<iframe src="/WebParts/FileUpLoad.aspx?<%=ParsValue %>" width="240px" height="22px" frameborder="0" scrolling="no"></iframe> 
</td> 
<td> 
<asp:TextBox runat="server" ID="tbFileName" style="display:none"></asp:TextBox> 
<div id="dvImg" runat="server" style="position:absolute; margin-left:50px;"> 
</div> 
</td> 
</tr> 
</table> 
<script language="javascript"> 
function <%=ClientID %>CallLoaded() 

<% =OnLoaded %>; 

</script> 

 

复制代码代码如下:

using System; 
using System.Collections; 
using System.Configuration; 
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 

public bool AutoFileName 

get 

object ob = ViewState[ClientID + "AutoFileName"]; 
if (ob == null) 
ob = true; 
return (bool)ob; 

set 

ViewState[ClientID + "AutoFileName"] = value; 


public string UpLoadPath 

get 

object ob = ViewState[ClientID + "UpLoadPath"]; 
if (ob == null) 
ob = "UPLOADFILES"; 
return ob.ToString(); 

set 

ViewState[ClientID + "UpLoadPath"] = value; 


public string OnLoaded 

get 

object ob = ViewState[ClientID + "OnLoaded"]; 
if (ob == null) 
ob = ""; 
return ob.ToString(); 

set 

ViewState[ClientID + "OnLoaded"] = value; 


public string SupportExtension 

get 

object ob = ViewState[ClientID + "SupportExtension"]; 
if (ob == null) 

ob = "gif|png|jpeg|jpg"; 

return ob.ToString(); 

set 

ViewState[ClientID + "SupportExtension"] = value.Replace(".", ""); 


public bool ShowImg 

get 

object ob = ViewState[ClientID + "ShowImg"]; 
if (ob == null) 
ob = true; 
return (bool)ob; 

set 

if ((bool)value) 
dvImg.Style["display"] = "block"; 
else 
dvImg.Style["display"] = "none"; 


public string FileName 

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:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="FileUpLoad.aspx.cs" Inherits="WebParts_FileUpLoad" %> 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head runat="server"> 
</head> 
<body style="margin:0px;"> 
<form id="form1" runat="server"> 
<div> 
<asp:FileUpload runat="server" ID="FileUpload1" onchange="upload(this);" /> 
<asp:Button runat="server" ID="btUp" style="display:none" OnClick="btUp_Click" /> 
</div> 
</form> 
</body> 
</html> 
<script language="javascript"> 
function upload(ob) 

var expStr=/.*(<%=SupportExtension%>)$/i; 
if(!expStr.test(ob.value)) 

alert("上传文件类型有误。\n(支持文件类型:<%=SupportExtension%>)"); 

else 

var btUp=document.getElementById("<%=btUp.ClientID %>"); 
btUp.click(); 


</script> 

 

复制代码代码如下:

using System; 
using System.Collections; 
using System.Configuration; 
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; 
using System.IO; 
public partial class WebParts_FileUpLoad : System.Web.UI.Page 

protected string SupportExtension = ""; 
protected string UpLoadPath = ""; 
protected bool AutoFileName; 
protected string ParentID = ""; 
protected void Page_Load(object sender, EventArgs e) 

SupportExtension = Request.QueryString["SupportExtension"]; 
UpLoadPath = Request.QueryString["UpLoadPath"]; 
AutoFileName = bool.Parse(Request.QueryString["AutoFileName"].ToString()); 
ParentID = Request.QueryString["ID"].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 = SupportExtension.Split(new string[] { "|" }, StringSplitOptions.RemoveEmptyEntries); 
for (int i = 0; i < allowedExtensions.Length; i++) 

if (fileExtension == "." + allowedExtensions[i]) 

fileOK = true; 


if (fileOK) 

string path = ""; 
string name = ""; 
string sPath = ""; 
if (AutoFileName) 

name = DateTime.Now.Ticks.ToString() + 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 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 = 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 < 2 * 1024 * 1024) //如果图片小于2M 

try 

FileUpload1.SaveAs(path); //使用saveAS方法保存文件 
System.Drawing.Image image = System.Drawing.Image.FromFile(path); 
if (image.Width > 800 || image.Height > 600) 

MakeThumbnail(webFilePath, webFilePath_s, 800, 600, "W");//生成缩略图的方法 

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.RegisterClientScriptBlock("succcess", @"<script> 
alert('上传成功'); 
parent.document.getElementById('" + ParentID + "_" + "tbFileName" + @"').value='" + fileName_s + @"'; 
</script>"); 

catch (Exception ex) 

Page.RegisterClientScriptBlock("err", "<script>alert('提示:文件上传失败,失败原因::" + ex.Message + "');</script>"); 


else 

Page.RegisterClientScriptBlock("err", "<script>alert('提示:图片不能大于2M');</script>"); 


else 

this.Page.RegisterClientScriptBlock("err", "<script>alert('图片重复');</script>"); 


catch (System.Exception err) 

this.Page.RegisterClientScriptBlock("err", "<script>alert('" + err.Message + "');</script>"); 

try 

Bitmap bmp = new Bitmap(path); 
int width = 0, height = 0; 
int dvalue = 200; 
if (bmp.Width < dvalue & bmp.Height < 200) 

width = bmp.Width; 
height = bmp.Height; 

else if (bmp.Width > bmp.Height) 

width = dvalue; 
height = dvalue * (bmp.Width / bmp.Height); 

else 

height = dvalue; 
width = dvalue * (bmp.Height / bmp.Width); 

this.Page.RegisterClientScriptBlock("show", @"<script> 
parent.VarValue='" + UpLoadPath + "/" + fileName_s + "';" + 
"parent." + ParentID + "CallLoaded();" + 
"parent.document.getElementById('" + ParentID + "_" + "dvImg" + @"').innerHTML=""" + 
"<img src='//www.zzvips.com/" + UpLoadPath + "/" + fileName_s + "' style='width:" + width.ToString() + "px; height:" + height + "px;'/>" + @"""; 
</script>"); 
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", "<script>alert('error');</script>"); 



/// <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> 
public void MakeThumbnail(string originalImagePath, 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) 

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 
System.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.SmoothingMode.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(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg); 

catch (System.Exception e) 

throw e; 

finally 

originalImage.Dispose(); 
bitmap.Dispose(); 
g.Dispose(); 


/// <summary> 
/// 在图片上增加文字水印 
/// </summary> 
/// <param name="Path">原服务器图片路径</param> 
/// <param name="Path_sy">生成的带文字水印的图片路径</param> 
protected void AddShuiYinWord(string Path, string Path_sy) 

string addText = "//www.zzvips.com"; 
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.SolidBrush(System.Drawing.Color.Blue); 
g.DrawString(addText, f, b, 15, 15); 
g.Dispose(); 
image.Save(Path_sy); 
image.Dispose(); 

/// <summary> 
/// 在图片上生成图片水印 
/// </summary> 
/// <param name="Path">原服务器图片路径</param> 
/// <param name="Path_syp">生成的带图片水印的图片路径</param> 
/// <param name="Path_sypf">水印图片路径</param> 
protected void AddShuiYinPic(string Path, string Path_syp, string Path_sypf) 

System.Drawing.Image image = System.Drawing.Image.FromFile(Path); 
System.Drawing.Image copyImage = System.Drawing.Image.FromFile(Path_sypf); 
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image); 
g.DrawImage(copyImage, new System.Drawing.Rectangle(image.Width - copyImage.Width, image.Height - copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width, copyImage.Height, System.Drawing.GraphicsUnit.Pixel); 
g.Dispose(); 
image.Save(Path_syp); 
image.Dispose(); 


属性: 
SupportExtension 自定义上传的格式,用"|"分隔; 
UpLoadPath   自定义上传到服务器的文件夹; 
AutoFileName  ture表示根据时间自动生成文件名,不会重复,false表示原来的图片名称,重复会覆盖. 

转载请注明出处 
2009-12-24 18:39:27 by 齐学佳

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