C# 无法访问要保存在数据库中的变量_C#_Asp.net_Asp.net Mvc_Entity Framework_Entity Framework 6

C# 无法访问要保存在数据库中的变量

c# asp.net asp.net-mvc entity-framework

C# 无法访问要保存在数据库中的变量,c#,asp.net,asp.net-mvc,entity-framework,entity-framework-6,C#,Asp.net,Asp.net Mvc,Entity Framework,Entity Framework 6,我正在做一个扩展方法，我希望我的变量image等于我的pic的名称扩展方法： public async Task<string> CreateNewSlider(Slider slider, HttpPostedFileBase file) // file always return null { string pic = null; if (file != null) { pic = System.

我正在做一个扩展方法，我希望我的变量

image

等于我的pic的名称

扩展方法：

 public async Task<string> CreateNewSlider(Slider slider, HttpPostedFileBase file) // file always return null
    {
        string pic = null;
        if (file != null)
        {
            pic = System.IO.Path.GetFileName(file.FileName);
            string path = System.IO.Path.Combine(
                                   System.Web.HttpContext.Current.Server.MapPath("~/Content/images/slider"), pic);
            file.SaveAs(path);

            using (var ms = new MemoryStream())
            {
                file.InputStream.CopyTo(ms);
                byte[] array = ms.GetBuffer();
            }
        }
        try
        {
            var createnewslider = new Slider
            {
                Alt = slider.Alt,
                CreationDate = slider.CreationDate,
                Description = slider.Description,
                IsVisible = slider.IsVisible,
                Order = slider.Order,
                Subtitle = slider.Subtitle,
                Title = slider.Title,
                VideoLink = slider.VideoLink,
                Image = pic
            };
            db.SlidersList.Add(createnewslider);
            await db.SaveChangesAsync();
            return "Slider Photo " + file + "has been created successfull";

        }
        catch (Exception ex)
        {
            return ex.InnerException.Message + "Contact to administrator";
        }

    }

创建视图：

@model xxx.Models.Slider

@{
ViewBag.Title = "Create";
}

<h2>Create</h2>

 @using (Html.BeginForm()) 
 {
@Html.AntiForgeryToken()

<div class="form-horizontal">
    <h4>Slider</h4>
    <hr />
    @Html.ValidationSummary(true, "", new { @class = "text-danger" })


    <div class="form-group">
        @Html.LabelFor(model => model.Title, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Title, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Title, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Order, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Order, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Order, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Subtitle, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Subtitle, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Subtitle, "", 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.EditorFor(model => model.Description, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Description, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Image, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
           @using (Html.BeginForm("Create", "Slider", FormMethod.Post,
                        new { enctype = "multipart/form-data" }))
           {
            <label for="file">Subir imágen:</label>
            <input type="file" name="file" id="file" style="width: 100%;" />
           }
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Alt, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Alt, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Alt, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.VideoLink, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.VideoLink, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.VideoLink, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.CreationDate, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.CreationDate, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.CreationDate, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.IsVisible, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            <div class="checkbox">
                @Html.EditorFor(model => model.IsVisible)
                @Html.ValidationMessageFor(model => model.IsVisible, "", new { @class = "text-danger" })
            </div>
        </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>
@Html.ActionLink("Back to List", "Index")
</div>

@model xxx.Models.Slider
@{
ViewBag.Title=“创建”；
}
创造
@使用（Html.BeginForm（））
{
@Html.AntiForgeryToken（）
滑块

@Html.ValidationSummary（true，“，new{@class=“text danger”}）
@LabelFor（model=>model.Title，htmlAttributes:new{@class=“controllabel col-md-2”}）
@EditorFor（model=>model.Title，new{htmlAttributes=new{@class=“form control”}）
@Html.ValidationMessageFor（model=>model.Title，“，new{@class=“text danger”}）
@LabelFor（model=>model.Order，htmlAttributes:new{@class=“controllabel col-md-2”}）
@EditorFor（model=>model.Order，new{htmlAttributes=new{@class=“form control”}）
@Html.ValidationMessageFor（model=>model.Order，“，new{@class=“text danger”}）
@LabelFor（model=>model.Subtitle，htmlAttributes:new{@class=“controllabel col-md-2”}）
@EditorFor（model=>model.Subtitle，new{htmlAttributes=new{@class=“form control”}）
@Html.ValidationMessageFor（model=>model.Subtitle，“，new{@class=“text danger”}）
@LabelFor（model=>model.Description，htmlAttributes:new{@class=“controllabel col-md-2”}）
@EditorFor（model=>model.Description，new{htmlAttributes=new{@class=“form control”}）
@Html.ValidationMessageFor（model=>model.Description，“，new{@class=“text danger”}）
@LabelFor（model=>model.Image，htmlAttributes:new{@class=“controllabel col-md-2”}）
@使用（Html.BeginForm（“创建”、“滑块”、FormMethod.Post、，
新的{enctype=“multipart/form data”}）
{
苏比尔·伊马根：
}
@LabelFor（model=>model.Alt，htmlAttributes:new{@class=“controllabel col-md-2”}）
@EditorFor（model=>model.Alt，new{htmlAttributes=new{@class=“form control”}）
@Html.ValidationMessageFor（model=>model.Alt，“，new{@class=“text danger”}）
@LabelFor（model=>model.VideoLink，htmlAttributes:new{@class=“controllabel col-md-2”}）
@EditorFor（model=>model.VideoLink，new{htmlAttributes=new{@class=“form control”}}）
@Html.ValidationMessageFor（model=>model.VideoLink，“，new{@class=“text danger”}）
@LabelFor（model=>model.CreationDate，htmlAttributes:new{@class=“controllabel col-md-2”}）
@EditorFor（model=>model.CreationDate，new{htmlAttributes=new{@class=“form control”}}）
@Html.ValidationMessageFor（model=>model.CreationDate，“，new{@class=“text danger”}）
@LabelFor（model=>model.IsVisible，htmlAttributes:new{@class=“controllabel col-md-2”}）
@EditorFor（model=>model.IsVisible）
@Html.ValidationMessageFor（model=>model.IsVisible，“，new{@class=“text danger”}）
}
@ActionLink（“返回列表”、“索引”）

在扩展方法中，它传递捕获异常并返回它

我使用调试模式，文件变量总是空的，但我不知道为什么这是因为

pic

在

createnewslider

对象的范围内不可用。只需在if语句之外声明

pic

变量：

string pic = string.Empty;

if (file != null) {
    pic = System.IO.Path.GetFileName(file.FileName);
    string path = System.IO.Path.Combine(
    HostingEnvironment.MapPath("~/Content/images/slider"), pic);
    file.SaveAs(path);

    using (MemoryStream ms = new MemoryStream()) {
        file.InputStream.CopyTo(ms);
        byte[] array = ms.GetBuffer();
    }
}
var createnewslider = new Slider
{
    Alt = slider.Alt,
    CreationDate = slider.CreationDate,
    Description = slider.Description,
    IsVisible = slider.IsVisible,
    Order = slider.Order,
    Subtitle = slider.Subtitle,
    Title = slider.Title,
    VideoLink = slider.VideoLink,
    Image = pic
};

在映射到

图像之前检查内容这是因为pic
在createnewslider
对象的范围内不可用。只需在if语句之外声明pic
变量：
string pic = string.Empty;

if (file != null) {
    pic = System.IO.Path.GetFileName(file.FileName);
    string path = System.IO.Path.Combine(
    HostingEnvironment.MapPath("~/Content/images/slider"), pic);
    file.SaveAs(path);

    using (MemoryStream ms = new MemoryStream()) {
        file.InputStream.CopyTo(ms);
        byte[] array = ms.GetBuffer();
    }
}
var createnewslider = new Slider
{
    Alt = slider.Alt,
    CreationDate = slider.CreationDate,
    Description = slider.Description,
    IsVisible = slider.IsVisible,
    Order = slider.Order,
    Subtitle = slider.Subtitle,
    Title = slider.Title,
    VideoLink = slider.VideoLink,
    Image = pic
};

并在映射到图像之前检查内容
将其定义在与构造函数相同的范围内，以便构造函数可以访问它
public async Task<string> CreateNewSlider(Slider slider, HttpPostedFileBase file)
{
    string pic = null;
    if (file != null)
    {
        pic = System.IO.Path.GetFileName(file.FileName);
        string path = System.IO.Path.Combine(
                               HostingEnvironment.MapPath("~/Content/images/slider"), pic);
        file.SaveAs(path);

        using (MemoryStream ms = new MemoryStream())
        {
            file.InputStream.CopyTo(ms);
            byte[] array = ms.GetBuffer();
        }
    }
    var createnewslider = new Slider
    {
        Alt = slider.Alt,
        CreationDate = slider.CreationDate,
        Description = slider.Description,
        IsVisible = slider.IsVisible,
        Order = slider.Order,
        Subtitle = slider.Subtitle,
        Title = slider.Title,
        VideoLink = slider.VideoLink,
        Image = pic // I can´t access to pic variable 

    };
    db.SlidersList.Add(createnewslider);
    await db.SaveChangesAsync();
    return "Slider Photo " + file + "has been created";

}

公共异步任务CreateNewSlider（滑块，HttpPostedFileBase文件）
{
字符串pic=null；
如果（文件！=null）
{
pic=System.IO.Path.GetFileName（file.FileName）；
字符串路径=System.IO.path.Combine(
HostingEnvironment.MapPath（“~/Content/images/slider”），pic）；
file.SaveAs（路径）；
使用（MemoryStream ms=new MemoryStream（））
{
file.InputStream.CopyTo（ms）；
字节[]数组=ms.GetBuffer（）；
}
}
var createnewslider=新滑块
{
Alt=滑块。Alt，
CreationDate=滑块。CreationDate，
Description=滑块。Description，
IsVisible=滑块。IsVisible，
顺序=滑块。顺序，
副标题=滑块。副标题，
标题=滑块。标题，
VideoLink=slider.VideoLink，
Image=pic//我无法访问pic变量
};
db.SlidersList.Add（createnewslider）；
等待db.saveChangesSync（）；
返回“滑块照片”+文件+“已创建”；
}

在与构造函数相同的范围内定义它，以便构造函数可以访问它

public async Task<string> CreateNewSlider(Slider slider, HttpPostedFileBase file)
{
    string pic = null;
    if (file != null)
    {
        pic = System.IO.Path.GetFileName(file.FileName);
        string path = System.IO.Path.Combine(
                               HostingEnvironment.MapPath("~/Content/images/slider"), pic);
        file.SaveAs(path);

        using (MemoryStream ms = new MemoryStream())
        {
            file.InputStream.CopyTo(ms);
            byte[] array = ms.GetBuffer();
        }
    }
    var createnewslider = new Slider
    {
        Alt = slider.Alt,
        CreationDate = slider.CreationDate,
        Description = slider.Description,
        IsVisible = slider.IsVisible,
        Order = slider.Order,
        Subtitle = slider.Subtitle,
        Title = slider.Title,
        VideoLink = slider.VideoLink,
        Image = pic // I can´t access to pic variable 

    };
    db.SlidersList.Add(createnewslider);
    await db.SaveChangesAsync();
    return "Slider Photo " + file + "has been created";

}

公共异步任务CreateNewSlider（滑块，HttpPostedFileBase文件） { 字符串pic=null；如果（文件！=null） { pic=System.IO.Path.GetFileName（file.FileName）；字符串路径=System.IO.path.Combine( HostingEnvironment.MapPath（“~/Content/images/slider”），pic）； file.SaveAs（路径）；使用（MemoryStream ms=new MemoryStream（）） { file.InputStream.CopyTo（ms）；字节[]数组=ms.GetBuffer（）； }