HTML5上传图片预览

<!DOCTYPE html>
<html>
<head>
<title>HTML5上传图片预览</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script src="/js/jquery.js"></script>
</head>
<body>
<h3>请选择图片文件:JPG/GIF</h3>
<form name="form0" id="form0" runat="server" enctype="multipart/form-data" >
<input type="file" name="file0" id="file0" multiple="multiple" /><br><img src="" id="img0" >
<asp:Button ID="Button1" runat="server" Text="保存" onclick="Button1_Click" />
<script>    
$("#file0").change(function(){
    var objUrl = getObjectURL(this.files[0]) ;
    console.log("objUrl = "+objUrl) ;
    if (objUrl) {
        $("#img0").attr("src", objUrl) ;
    }
}) ;
//建立一個可存取到該file的url
function getObjectURL(file) {
    var url = null ; 
    if (window.createObjectURL!=undefined) { // basic
        url = window.createObjectURL(file) ;
    } else if (window.URL!=undefined) { // mozilla(firefox)
        url = window.URL.createObjectURL(file) ;
    } else if (window.webkitURL!=undefined) { // webkit or chrome
        url = window.webkitURL.createObjectURL(file) ;
    }
    return url ;
}
</script>
</form>
</body>

</html>

后台:

using System.IO;
using System.Drawing;
public partial class demo : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    //保存图片
    protected void Button1_Click(object sender, EventArgs e)
    {
        HttpPostedFile imgfile =  Request.Files["file0"];
        imgfile.SaveAs(Server.MapPath("~/abc.jpg"));
    }
}

如图:

说明:表单中enctype="multipart/form-data"的意思,是设置表单的MIME编码。默认情况,这个编码格式是application/x-www-form-urlencoded,不能用于文件上传;只有使用了

multipart/form-data,才能完整的传递文件数据。




原文地址:https://www.cnblogs.com/gosky/p/4955627.html