在init之后的事件定义中,为什么我会收到错误18使用未分配的局部变量&before; 39E beforeEvntDrawArg'

时间:2015-04-24 19:30:06

标签: c# asp.net-mvc events compiler-errors

我有一个事件对象......

public class BeforeEvntDrawArgs
{
    /// <summary>
    /// Event html. 
    /// </summary>      
    internal string InnerHTML
    {
        get
        {
            return this.Html;
        }
        set
        {
            this.Html = value;
        }
    }

    /// <summary>
    /// Event tags, using Data TagFields.
    /// </summary>
    public Gamex.TagCollection Tag
    {
        get;
        private set;
    }

    /// <summary>
    /// Event text.
    /// </summary>
    public string Text
    {
        get;
        private set;
    }

    /// <summary>
    /// Event Clue.
    /// </summary>
    public string HoverOver
    {
        get;
        set;
    }

    internal BeforeEvntDrawArgs(Event e, string[] fields)
    {

        this.Id = e.Id;
        this.Text = e.Text;

        if (e.Tags != null)
        {
            this.Tag = new Gamex.TagCollection(fields, new List<string>(e.Tags));
        }


    }
}

在尝试冒泡活动并复制详细信息时,我收到错误18使用未分配的本地变量&#39; beforeEntDrawArg&#39;

如果我指定null BeforeEvntDrawArgs beforeEvntDrawArg = null;,那么它编译得很好,因为应用程序炸弹说null ref。不确定我做错了什么,你能帮我纠正这段代码吗?

但是在我复制和初始化时的事件正文中,我做错了什么,为什么我在编译时得到一个未初始化的,如果我使用null,为什么它会在运行时中断?请让我知道如何解决这个问题..

  private BeforeEvntDrawArgs DoBeforeEvntDraw(Event e)
     {
         // Issue begins here, and pre-initializing to null compiles, 
         // however breaks on runtime as a null ref
         BeforeEvntDrawArgs beforeEvntDrawArg = new BeforeEvntDrawArgs(e, this.TagFields)
         {
            HoverOver = Encoder.HtmlEncode(beforeEvntDrawArg.Text),
            InnerHtml = Encoder.HtmlEncode(beforeEvntDrawArg.Text)
         };
         this.OnBeforeEvntDraw(beforeEvntDrawArg);
         return beforeEvntDrawArg;
     }

错误18使用未分配的本地变量&#39; beforeEvntDrawArg&#39;

2 个答案:

答案 0 :(得分:1)

您正尝试在其自己的对象初始值设定项中使用beforeEvntDrawArg。这不受支持。 https://msdn.microsoft.com/en-us/library/bb397680.aspx

试试这个。没有对象初始化语法,它完全一样。

BeforeEvntDrawArgs beforeEvntDrawArg = new BeforeEvntDrawArgs(e, this.TagFields)
beforeEvntDrawArg.HoverOver = Encoder.HtmlEncode(beforeEvntDrawArg.Text);
beforeEvntDrawArg.InnerHtml = Encoder.HtmlEncode(beforeEvntDrawArg.Text);

答案 1 :(得分:1)

我没有看到你发布的课程中的任何地方(BeforeEvntDrawArgs )一个带有2个参数的构造函数的定义。这意味着唯一可用的构造函数将是默认的无参数构造函数。所以当你试图执行

HoverOver = Encoder.HtmlEncode(beforeEvntDrawArg.Text)

beforeEvntDrawArg.Text尚未分配值。