[英]Cannot make Byte a Required Field
有一個我想上傳圖像的應用程序。 我為此使用字節數組。
該圖像是必需的,但是當我將該注釋放在變量上並嘗試創建圖像時,當該圖像應具有該圖像時,它會給我錯誤消息。 它還返回模型無效。
當我刪除Required時,它可以工作,但也可以將其設置為null,這是我不想要的。
關於堆棧溢出的話題似乎並不多。
這是我的模特
[Key]
public int InvoiceId { get; set; }
[Required(ErrorMessage = "Company is required")]
public string Company { get; set; }
[Required(ErrorMessage = "Description is required")]
public string Description { get; set; }
[Required(ErrorMessage = "Amount is required")]
public decimal Amount { get; set; }
[Required(ErrorMessage = "Picture of Invoice Required")]
public byte[] PictureOfInvoice { get; set; }
而我的控制器:
[HttpPost]
[ValidateAntiForgeryToken]
[Authorize(Roles = "Parish Admin, Priest, Administrator")]
public ActionResult Create([Bind(Include = "InvoiceId,Company,Description,Amount,PictureOfInvoice,DateReceived,ChurchId")] Invoice invoice,HttpPostedFileBase File)
{
if (ModelState.IsValid)
{
if (File != null && File.ContentLength > 0)
{
invoice.PictureOfInvoice = new byte[File.ContentLength];
File.InputStream.Read(invoice.PictureOfInvoice, 0, File.ContentLength);
}
else
{
TempData["Error"] = "Upload an Image";
}
db.Invoices.Add(invoice);
db.SaveChanges();
return RedirectToAction("Index");
}
ViewBag.ChurchId = new SelectList(db.Churches, "ChurchId", "Name", invoice.ChurchId);
return View(invoice);
}
我的視圖以防萬一
<h2>Add New Invoice</h2>
@if (TempData["Error"] != null)
{
<div style="color:red">@TempData["Error"]</div>
}
@using (Html.BeginForm("Create", "Invoices", FormMethod.Post, new { @class = "form-horizontal", enctype = "multipart/form-data" }))
{
@Html.AntiForgeryToken()
@Html.ValidationSummary()
<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>
<div class="form-horizontal">
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
<div class="form-group">
@Html.LabelFor(model => model.Company, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.TextBoxFor(model => model.Company, new { htmlAttributes = new { @class = "form-control", style = "width:20em;" } })
@Html.ValidationMessageFor(model => model.Company, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Amount, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.TextBoxFor(model => model.Amount,new { htmlAttributes = new { @class = "form-control", style = "width:20em;" } })
@Html.ValidationMessageFor(model => model.Amount, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.DateReceived, "DateRecieved", htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.TextBoxFor(model => model.DateReceived, new { htmlAttributes = new { @class = "form-control", style = "width:20em;" } })
@Html.ValidationMessageFor(model => model.DateReceived, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Description, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.TextBoxFor(model => model.Description, new { htmlAttributes = new { @class = "form-control", style = "width:20em;" } })
@Html.ValidationMessageFor(model => model.Description, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.PictureOfInvoice, "Picture of Invoice", htmlAttributes: new { @class = "control-label col-md-2"})
<div class="col-md-10">
<input type="file" name="File" id="File" style="width: 50%;" />
@Html.ValidationMessageFor(model => model.PictureOfInvoice, "", new { @class = "text-danger" })
<output id="list"></output>
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.ChurchId, "Church Name", htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownList("ChurchId", null, htmlAttributes: new { @class = "form-control", style = "width:20em;" })
@Html.ValidationMessageFor(model => model.ChurchId, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</div>
</div>
}
<div>
<u>
@Html.ActionLink("Back to List", "Index")
</u>
</div>
<script src="~/Scripts/jquery.datetimepicker.js"></script>
<script>
$('#DateReceived').datetimepicker({
format: 'd/m/Y',
weeks: true,
disableWeekDays: [0, 1, 3, 4, 5, 6],
timepicker: false,
inline: false
});
function handleFileSelect(evt) {
var files = evt.target.files; // FileList object
// Loop through the FileList and render image files as thumbnails.
for (var i = 0, f; f = files[i]; i++) {
// Only process image files.
if (!f.type.match('image.*')) {
continue;
}
var reader = new FileReader();
// Closure to capture the file information.
reader.onload = (function (theFile) {
return function (e) {
// Render thumbnail.
var span = document.createElement('span');
span.innerHTML = ['<img class="thumb" src="', e.target.result,
'" title="', escape(theFile.name), '"/>'
].join('');
document.getElementById('list').insertBefore(span, null);
};
})(f);
// Read in the image file as a data URL.
reader.readAsDataURL(f);
}
}
document.getElementById('File').addEventListener('change', handleFileSelect, false);
</script>
這里混合的關注是導致問題的原因。 看來您正在嘗試將實體用作視圖的模型,並使其同時滿足UI驗證和持久性驗證。
將兩個問題分開。
創建特定於視圖所需行為的視圖模型。 該模型還應包括IEnumerable<SelectListItem> ChurchList
屬性以填充下拉列表。
public class CreateInvoiceViewModel {
[Required(ErrorMessage = "Company is required")]
public string Company { get; set; }
[Required(ErrorMessage = "Description is required")]
public string Description { get; set; }
[Required(ErrorMessage = "Amount is required")]
public decimal Amount { get; set; }
[Required(ErrorMessage = "Picture of Invoice Required")]
public HttpPostedFileBase File { get; set; }
public int ChurchId { get; set; }
public IEnumerable<SelectListItem> ChurchList { get; set; }
//...other properties
}
並將其設置為視圖的模型
@model CreateInvoiceViewModel
如果創建新發票,則尚未分配ID。 這意味着當發布當前模型時,模型狀態不能有效,因為InvoiceId
不會被標記為Required
。
上傳的文件(發票圖片)也應包含在視圖模型中,並應使用@Html.TextBoxFor(m => m.File, new { type = "file" })
獲得客戶端驗證。 模型綁定器將根據是否提供匹配的輸入來設置該屬性。
<div class="form-group">
@Html.LabelFor(model => model.File, "Picture of Invoice", htmlAttributes: new { @class = "control-label col-md-2"})
<div class="col-md-10">
@Html.TextBoxFor(model => model.File, new { type = "file", style = "width: 50%;"})
@Html.ValidationMessageFor(model => model.File, "", new { @class = "text-danger" })
<output id="list"></output>
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.ChurchId, "Church Name", htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownListFor(model => model.ChurchId, (IEnumerable<SelectListItem>)@Model.ChurchList, htmlAttributes: new { @class = "form-control", style = "width:20em;" })
@Html.ValidationMessageFor(model => model.ChurchId, "", new { @class = "text-danger" })
</div>
</div>
因此,現在在控制器端,應刪除[Bind]
因為在使用視圖模型時不需要使用[Bind]
。
[HttpGet]
[Authorize(Roles = "Parish Admin, Priest, Administrator")]
public ActionResult Create() {
var model = new CreateInvoiceViewModel {
//set default property values as needed
};
model.ChurchList = new SelectList(db.Churches, "ChurchId", "Name");
//...
return View(model);
}
[HttpPost]
[ValidateAntiForgeryToken]
[Authorize(Roles = "Parish Admin, Priest, Administrator")]
public ActionResult Create(CreateInvoiceViewModel model) {
if (ModelState.IsValid) {
var file = model.File;
//copy properties over to entity
var invoice = new Invoice {
Company = model.Company,
Description = model.Description,
Amount = model.Amount,
DateReceived = model.DateReceived,
ChurchId = model.ChurchId,
//create array for file contents
PictureOfInvoice = new byte[file.ContentLength]
};
//populate byte array
file.InputStream.Read(invoice.PictureOfInvoice, 0, file.ContentLength);
db.Invoices.Add(invoice);
db.SaveChanges();
return RedirectToAction("Index");
}
//if we get this far model state is invalid.
//return view with validation errors.
model.ChurchList = new SelectList(db.Churches, "ChurchId", "Name", model.ChurchId);
return View(model);
}
如果模型要求無效,則模型狀態將提供必要的反饋。 無需使用臨時數據和文件檢查。
您沒有在模型中使用數據綁定來填充PictureOfInvoice
,而是在控制器的方法中進行的。 但是,只有在確認模型有效之后才執行該步驟,而根據此邏輯,模型將無效。
我認為您可以嘗試僅切換前幾位:
[HttpPost]
[ValidateAntiForgeryToken]
[Authorize(Roles = "Parish Admin, Priest, Administrator")]
public ActionResult Create(
[Bind(Include = "InvoiceId,Company,Description,Amount,DateReceived,ChurchId")]
Invoice invoice,
HttpPostedFileBase File)
{
if (invoice!=null && File != null && File.ContentLength > 0)
{
invoice.PictureOfInvoice = new byte[File.ContentLength];
File.InputStream.Read(invoice.PictureOfInvoice, 0, File.ContentLength);
}
if (ModelState.IsValid)
{
//Proceed
如果仍然不能讓模型通過驗證,那么您可能必須像以前在else
繼續應用錯誤。
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