有没有办法在此处添加一条“强制”图像？
// the if branch
template <typename T>
auto do_refresh (T* loader) -> decltype(
loader->refresh(), // <-- "can_do_this" part
bool())
{
loader->refresh();
return false;
};
// the else branch
template <typename T>
auto do_refresh (...) -> bool
{
return false;
}
bool refresh()
{
return do_refresh(_loader);
}
如果没有，是否有像
这样的功能 @FileUpload.GetHtml(
initialNumberOfFiles:4,
allowMoreFilesToBeAdded:false,
includeFormTag:true,
???Image only kind of line????
uploadText:"Send")
我知道接受属性
if(IsPost && Validation.IsValid()){
var uploadedFile1 = Request.Files[0];
var uploadedFile2 = Request.Files[1];
if(Path.GetFileName(uploadedFile1.FileName) != String.Empty){
var fileName1 = Path.GetFileName(uploadedFile1.FileName);
var fileSavePath1 = Server.MapPath("/path/UploadedFiles/" + DateP + fileName1);
uploadedFile1.SaveAs(fileSavePath1);
image1 = "/path/UploadedFiles/" + DateP + fileName1;
}
if(Path.GetFileName(uploadedFile2.FileName) != String.Empty){
var fileName2 = Path.GetFileName(uploadedFile2.FileName);
var fileSavePath2 = Server.MapPath("/path/UploadedFiles/" + DateP + fileName2);
uploadedFile2.SaveAs(fileSavePath2);
image2 = "/path/UploadedFiles/" + DateP + fileName2;
}
???Like if filename extension is different than jpg or gif, or bmp then "hell no, i'm not uploading this" kind of function????
但是将其添加到此代码中似乎并不那么简单......
谢谢
答案 0 :(得分：1)
required changes并不困难：
using System;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Web;
using System.Web.Mvc;
using Microsoft.Internal.Web.Utils;
using Microsoft.Web.Helpers.Resources;
namespace YourNamespaceHere
{
// Extended to include accept attribute
// Original: https://github.com/ASP-NET-MVC/ASP.NET-Mvc-3/blob/master/webpages/src/Microsoft.Web.Helpers/FileUpload.cs
public static class FileUploadEx
{
/// <summary>
/// Creates HTML for multiple file upload.
/// </summary>
/// <param name="name">The value assigned to the name attribute of the file upload input elements.</param>
/// <param name="initialNumberOfFiles">Initial number of file upload fields to display.</param>
/// <param name="allowMoreFilesToBeAdded">If true, allows more file upload fields to be added.</param>
/// <param name="includeFormTag">If true, result includes form tag around all file input tags and submit button.
/// If false, user needs to specify their own form tag around call to GetHtml with their own submit button.</param>
/// <param name="addText">Text to display on a link that allows more file upload fields can be added.</param>
/// <param name="uploadText">Text to display on the submit button.</param>
/// <param name="allowedTypes">Comma-separated string for the allowed MIME types for the input element.</param>
public static HtmlString GetHtml(
string name = null,
int initialNumberOfFiles = 1,
bool allowMoreFilesToBeAdded = true,
bool includeFormTag = true,
string addText = null,
string uploadText = null,
string allowedTypes = null)
{
HttpContextBase httpContext = new HttpContextWrapper(HttpContext.Current);
FileUploadImplementation fileUpload = new FileUploadImplementation(httpContext);
return fileUpload.GetHtml(name: name, initialNumberOfFiles: initialNumberOfFiles, allowMoreFilesToBeAdded: allowMoreFilesToBeAdded, includeFormTag: includeFormTag,
addText: addText, uploadText: uploadText, allowedTypes: allowedTypes);
}
}
internal class FileUploadImplementation
{
private static readonly object _countKey = new object();
private static readonly object _scriptAlreadyRendered = new object();
private readonly HttpContextBase _httpContext;
public FileUploadImplementation(HttpContextBase httpContext)
{
_httpContext = httpContext;
}
private int RenderCount
{
get
{
int? count = _httpContext.Items[_countKey] as int?;
if (!count.HasValue)
{
count = 0;
}
return count.Value;
}
set
{
_httpContext.Items[_countKey] = value;
}
}
private bool ScriptAlreadyRendered
{
get
{
bool? rendered = _httpContext.Items[_scriptAlreadyRendered] as bool?;
return rendered.HasValue && rendered.Value;
}
set
{
_httpContext.Items[_scriptAlreadyRendered] = value;
}
}
public HtmlString GetHtml(
string name,
int initialNumberOfFiles,
bool allowMoreFilesToBeAdded,
bool includeFormTag,
string addText,
string uploadText,
string allowedTypes)
{
if (initialNumberOfFiles < 0)
{
throw new ArgumentOutOfRangeException(
"initialNumberOfFiles",
String.Format(CultureInfo.InvariantCulture, CommonResources.Argument_Must_Be_GreaterThanOrEqualTo, "0"));
}
if (String.IsNullOrEmpty(addText))
{
addText = HelpersToolkitResources.FileUpload_AddMore;
}
if (String.IsNullOrEmpty(uploadText))
{
uploadText = HelpersToolkitResources.FileUpload_Upload;
}
if (String.IsNullOrEmpty(name))
{
name = "fileUpload";
}
TagBuilder formTag = null;
if (includeFormTag)
{
// <form method="post" enctype="multipart/form-data" >
formTag = new TagBuilder("form");
formTag.MergeAttribute("method", "post");
formTag.MergeAttribute("enctype", "multipart/form-data");
formTag.MergeAttribute("action", "");
}
// <div id="file-upload-all-files">
TagBuilder outerDivTag = new TagBuilder("div");
outerDivTag.MergeAttribute("id", "file-upload-" + RenderCount);
outerDivTag.MergeAttribute("class", "file-upload");
// <div><input type="file" name="fileUpload"/></div>
TagBuilder fileInputTag = new TagBuilder("input");
fileInputTag.MergeAttribute("type", "file");
fileInputTag.MergeAttribute("name", "fileUpload");
// ****************************************************************
// Added accept attribute
// *
if (!string.IsNullOrWhiteSpace(allowedTypes))
{
fileInputTag.MergeAttribute("accept", allowedTypes);
}
// *
// ****************************************************************
TagBuilder innerDivTag = new TagBuilder("div");
innerDivTag.InnerHtml = fileInputTag.ToString(TagRenderMode.SelfClosing);
outerDivTag.InnerHtml = String.Join(String.Empty, Enumerable.Repeat(innerDivTag.ToString(), initialNumberOfFiles));
TagBuilder aTag = null;
if (allowMoreFilesToBeAdded)
{
// <a href="#" onclick="FileUploadHelper.addInputElement(1, "foo"); return false;" >Add more!</a>
aTag = new TagBuilder("a");
aTag.MergeAttribute("href", "#");
aTag.MergeAttribute("onclick",
String.Format(CultureInfo.InvariantCulture,
"FileUploadHelper.addInputElement({0}, {1}); return false;",
RenderCount, HttpUtility.JavaScriptStringEncode(name, addDoubleQuotes: true)));
aTag.SetInnerText(addText);
}
// <input value="Upload" type="submit"/>
TagBuilder submitInputTag = null;
if (includeFormTag)
{
submitInputTag = new TagBuilder("input");
submitInputTag.MergeAttribute("type", "submit");
submitInputTag.MergeAttribute("value", uploadText);
}
StringBuilder finalHtml = new StringBuilder();
if (allowMoreFilesToBeAdded && !ScriptAlreadyRendered)
{
finalHtml.Append(_UploadScript);
ScriptAlreadyRendered = true;
}
if (includeFormTag)
{
StringBuilder formTagContent = new StringBuilder();
ComposeFileUploadTags(formTagContent, outerDivTag, aTag, submitInputTag);
formTag.InnerHtml = formTagContent.ToString();
finalHtml.Append(formTag.ToString());
}
else
{
ComposeFileUploadTags(finalHtml, outerDivTag, aTag, submitInputTag);
}
RenderCount++;
return new HtmlString(finalHtml.ToString());
}
private static void ComposeFileUploadTags(StringBuilder sb, TagBuilder outerDivTag, TagBuilder aTag, TagBuilder submitTag)
{
sb.Append(outerDivTag.ToString());
if ((aTag != null) || (submitTag != null))
{
TagBuilder divTag = new TagBuilder("div");
divTag.MergeAttribute("class", "file-upload-buttons");
StringBuilder innerHtml = new StringBuilder();
if (aTag != null)
{
innerHtml.Append(aTag.ToString());
}
if (submitTag != null)
{
innerHtml.Append(submitTag.ToString(TagRenderMode.SelfClosing));
}
divTag.InnerHtml = innerHtml.ToString();
sb.Append(divTag.ToString());
}
}
private const string _UploadScript =
"<script type=\"text/javascript\">" +
"if (!window[\"FileUploadHelper\"]) window[\"FileUploadHelper\"] = {}; " +
"FileUploadHelper.addInputElement = function(index, name) { " +
"var inputElem = document.createElement(\"input\"); " +
"inputElem.type = \"file\"; " +
"inputElem.name = name; " +
"var divElem = document.createElement(\"div\"); " +
"divElem.appendChild(inputElem.cloneNode(false)); " + //Appending the created node creates an editable text field in IE8.
"var inputs = document.getElementById(\"file-upload-\" + index); " +
"inputs.appendChild(divElem); " +
"} </script>";
}
}
问题是原始版本依赖于一些在Web项目中通常不会引用的程序集，因此您需要跟踪这些程序集：
如果您更喜欢客户端解决方案，可以使用jQuery添加相关属性：
$('input[name="fileUpload"]').attr({ 'accept', 'image/*' });
我不知道上述任何一项更改是如何影响助手的JavaScript的，所以请注意这一点。
答案 1 :(得分：0)
最后，我通过修改代码来完成所有工作
var filename1b = Path.GetExtension(uploadedFile1.FileName);
if (filename1b == ".jpg" || filename1b == ".JPG" || filename1b == ".gif" || filename1b == ".GIF" || filename1b == ".bmp" || filename1b == ".BMP" || filename1b == ".png" || filename1b == ".PNG")
它似乎有用......我应该抓住机会了解更多有关修改帮助者的信息，但我认为我缺少很多元素......对不起Tieson T。