上传图片

上传图片
aspx前端：
<div>
<asp:Image ID="Image1" runat="server" />//这个控件在浏览器中不显示
<span style="color:#eeff00">图片预览</span>
<asp:TextBox ID="txtCover" runat="server" ReadOnly=“true”></asp:TextBox>//显示存储图片的路径
<span style="color:#4cff00" >图片上传的路径</span></br>
<asp:FileUpload ID="imgupload" runat="server" />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
<asp:Button ID="btnUpload" runat="server" Text="上传" OnClick="btnUpload_Click" />
OnClick是鼠标点击跳转的事件 btnUpload_Click 是执行protected void btnUpload_Click(object sender, EventArgs e)这个事件
</div>
aspx.cs后台
protected void btnUpload_click(object sender,EventArgs e)
{

if(imgupload.PostedFile.FileName!="")
{
string imgPath=imgupload.PostedFile.FileName;
string extPath=imgPath.Substring(imgPath.LastIndexOf(".")+1)
if(extPath.ToLower()!="jpg"&&extPath.ToLower()!="png"&&extPath.ToLower()!="bmp")
{
Page.ClientScript.RegisterClientScriptBlock(GetType(), "", "<script language=javascript>alert(‘选择文件类型JPG，bmp，PNG‘)</script>");
}
else
{
string sPath=Server.MapPath("/UploadFiles/upload");
imgupload.PostedFile.SaveAs(sPath+"\\"+imgPath.Substring(imgPath.LastIndexOf("\\")+1);
sPath = sPath.Substring(sPath.LastIndexOf("\\") + 1); //sPath = 文件夹里的upload;
//在这里Spath被重置为\\upload
this.txtCover.Text = sPath + "/" + imgPath.Substring(imgPath.LastIndexOf("\\") + 1);//文件夹里的upload+xx.jpg;
// 这里txtCover的值为upload文件名.扩展名
Page.ClientScript.RegisterClientScriptBlock(GetType(), "", "<script language=javascript>alert(‘上传成功‘)</script>");
Image1.ImageUrl = "/UploadFiles/" + this.txtCover.Text;//?upload/$@B0)U`]TDA@MKRDW15BJQR.jpg
}
}
else
{
Page.ClientScript.RegisterClientScriptBlock(GetType(), "", "<script language=javascript>alert(‘请选择图片‘)</script>");

}