小编Kar*_*son的帖子

鉴于以下重载方法:

public string Test(long item)
{
    return "Test with a long was called!";
}

public string Test(int item)
{
    return "Test with an int was called!";
}

public string Test(object item)
{
    return "Test with an object was called!";
}

当我打电话时Test(),传递一个short,像这样:

short shortValue = 7;
var result = Test(shortValue);

为什么值result等于"Test with an int was called!",而不是"Test with an object was called!"？

我尝试执行以下连接：

var collection = from t1 in dt1.AsEnumerable()
                 join t2 in dt2.AsEnumerable()
                 on  new { 
                     t1.["main_code"], 
                     t1["year"]} 
                     equals new { 
                         t2["dep_code"], 
                         t2["dep_year"] }
                         select new { 
                             emp_name = t1["name"], 
                             bonus_desc = t1["bonus_desc"],
                             dep_name = t2["dep_name"] };

但我面临以下构建错误！

无效的匿名类型成员声明符

如何WebMethod从Windows应用程序在ASP.NET中调用它？

我尝试过使用web request post方法,但它返回了ASP.NET页面的XML.

这是我的网络方法:

[WebMethod()]
public static string Senddata(string value)
{
    return "datareceived" + value;
}

我在我的应用程序中使用Chosen Jquery下拉列表.不幸的是,当下拉列表位于updatepanel中时,它不起作用.

我知道脚本之间存在一些冲突.但无法追查它.任何帮助表示赞赏.

我的代码是:

<script src="/js/jquery-1.11.2.js" type="text/javascript"></script> 
<link href="../css/chosen.css"  rel="stylesheet" />
<script src="../js/chosen.jquery.js" type="text/javascript"></script>

<asp:UpdatePanel ID="upMain" runat="server">
    <ContentTemplate>
        <asp:DropDownList ID="DropDownList1" 
                          CssClass="form-control chosen" 
                          multiple runat="server">
            <asp:ListItem Text="Select Course" Value="0" 
                          CssClass="form-control" runat="server"/>
            <asp:ListItem Text="core java" Value="1" 
                          CssClass="form-control" runat="server" />                  
            <asp:ListItem Text="C" Value="2" 
                          CssClass="form-control" runat="server" /> 
            <asp:ListItem Text="C++" Value="3" 
                          CssClass="form-control" runat="server" />  
            <asp:ListItem Text="C#" Value="4" 
                          CssClass="form-control" runat="server" />
        </asp:DropDownList>
   </ContentTemplate>
</asp:UpdatePanel>

<script>
    jQuery(document).ready(function mchoose() { 
        jQuery(".chosen").data("placeholder", "Select Frameworks...").chosen();
    });
</script>

我理解这StringBuilder是在循环中连接字符串的选择,如下所示:

List<string> myListOfString = GetStringsFromDatabase();
var theStringBuilder = new StringBuilder();

foreach(string myString in myListOfString)
{
    theStringBuilder.Append(myString);
}

var result = theStringBuilder.ToString();

但是哪些场景StringBuilder表现优异String.Join(),反之亦然？

var theStringBuilder = new StringBuilder();
theStringBuilder.Append("Is this ");
theStringBuilder.Append("ever a good ");
theStringBuilder.Append("idea?");

var result = theStringBuilder.ToString();

要么

string result = String.Join(" ", new String[]
            {
                "Or", "is", "this", "a", "better", "solution", "?"
            });

任何指导将不胜感激.

编辑:是否有一个阈值,其中的创建开销StringBuilder是不值得的？

请帮帮我,为什么我的代码错了？我跟着这个.

这是我的代码背后:

public static string HelloName(string name)
{
    return "hello, " + name;
}

这是我的jQuery:

$('#Name').click(function () {
    var name = "step";
    //var dataValue = {"name":name};
    $.ajax({
        type: "POST",
        url: "Default.aspx/HelloName",
        data: JSON.stringify({ name: name }),
        contentType: "application/json;charset=utf-8",
        dataType: "JSON",
        success: function (msg) {
            var mes = msg.d;
            console.log(mes);
            $("#Name").text(mes);
        }
    });
});

我认为我正确地遵循了教程,但是当我使用Page Inspector/Network时,我得到的是HTTP 500内部错误.

请帮助我,我的错误和纠正这段代码.

在我的C#项目中,我收到此错误,计数的定义不包含 System.Array

protected void Page_Prerender(object sender, EventArgs e)
{
    FileInfo[] fileInfo;
    string UpFolder = Server.MapPath("~/data/images/");
    DirectoryInfo dir = new DirectoryInfo(UpFolder);
    fileInfo = dir.GetFiles();
    // here i am getting error
    int TotalImages = fileInfo.Count();
    for (int count = 0; count < TotalImages; count++)
    {
        Image image = new Image();
        image.ImageUrl = "~/data/images/" + fileInfo[count].ToString();
        image.ID = count.ToString();
        DataListImage.Controls.Add(image);
    }
    DataListImage.DataSource = dir.GetFiles();
    DataListImage.DataBind();

    string UpFolder1 = Server.MapPath("~/data/thumbnails/");
    DirectoryInfo dir1 = new DirectoryInfo(UpFolder1);
    DataListthumbnails.DataSource = dir1.GetFiles();
    DataListthumbnails.DataBind();
}

我创建了一个使用System.Reflection命名空间的项目.好吧,当我尝试使用该方法时GetInterfaces,我发现它在Windows应用商店中不存在.

我尝试创建一个扩展方法,我尝试使用其余的方法来创建一个类似的GetInterfaces,但我没有.

有没有办法GetInterfaces在Store Apps中使用？

我正在尝试从已定义结构的数组中添加/删除数据.

struct process
{
    public int Proc_Id;
    public int Proc_BurstTime;
    public int Proc_Priority;
    public override string ToString()
    {
        return "ID: " + Proc_Id.ToString() + " Time: " + Proc_BurstTime.ToString() + " Prior: " + Proc_Priority.ToString();
    }
};

readonly process[] ProcessList = new process[]
{
    new process{ Proc_Id = 1, Proc_BurstTime = 3000, Proc_Priority = 1},
    new process{ Proc_Id = 2, Proc_BurstTime = 5000, Proc_Priority = 2},
    new process{ Proc_Id = 3, Proc_BurstTime = 1000, Proc_Priority = 3},
    new process{ Proc_Id …

假设我有这个:

public class MyClass
{
    private readonly List<string> _strings = new List<string>();

    public IEnumerable<string> MyStrings 
    { 
        get 
        { 
            return _strings; 
        }
    }
}

如何防止以下实际添加到字符串的成员变量列表？

var theClass = new MyClass();
((List<string>)theClass.MyStrings).Add("I do not want to be able to add this!");