0

您好我正在尝试重新运行名为的数组类型ZverejnenyUcetType，但问题是该数组可能包含两种类型：StandartniUcetType和NestandardniUcetType。

所以问题是当我尝试像这样返回数组时：

  string[] dic_vstup = new string[] { (line) };
            RozhraniWSDL.InformaceOPlatciType[] dic_vystup;
            RozhraniWSDL.rozhraniCRPDPH srv = new RozhraniWSDL.rozhraniCRPDPH();
            StatusType status = srv.getStatusNespolehlivyPlatce(dic_vstup, out dic_vystup);
            string abc = status.bezVypisuUctu.ToString();   // If it is already a string, then ToString not needed


            for (int i = 0; i < dic_vystup.Length; i++)
            {
                RozhraniWSDL.InformaceOPlatciType info = dic_vystup[i];


for (int x = 0; x <= 3; x++)
{   
    file2.WriteLine((((RozhraniWSDL.StandardniUcetType)(info.zverejneneUcty[x].Item)).cislo) + "-"

        + (((RozhraniWSDL.StandardniUcetType)(info.zverejneneUcty[x].Item)).cislo) + "/" 

        + (((RozhraniWSDL.StandardniUcetType)(info.zverejneneUcty[x].Item)).kodBanky));     
}}

我得到以下异常：无法将类型的对象RozhraniWSDL.NestandardniUcetType转换为 type RozhraniWSDL.StandardniUcetType。

NestandardniUcetType仅包含一项 -cislo

StandartníUcetType有 3 个项目- predcislo, cislo,kod banky

这是数组的图像：

在此处输入图像描述

我认为解决方案可能是确定哪些结果是 type StandartniUcetType，哪些是NestandardniUcetType.

请问这样可以吗？

我发现这个解决方案更常见。

感谢您的时间。

4

3 回答 3

2

如果数组有两种不同的类型，您可以添加一条if语句，如下所示：

if (info.zverejneneUcty[x].Item is RozhraniWSDL.StandardniUcetType) {
    ...
} else {
    ...
}

更好的方法是使用as运算符进行转换，如下所示：

RozhraniWSDL.StandardniUcetType std = info.zverejneneUcty[x].Item as RozhraniWSDL.StandardniUcetType;
if (std != null) {
    ...
}
RozhraniWSDL.NestandardniUcetType nstd = info.zverejneneUcty[x].Item as RozhraniWSDL.NestandardniUcetType;
if (nstd != null) {
    ...
}

最后，一个非常好的方法是为这两种类型编写两个单独的方法，并使用dynamic它来执行调度。为此，请定义两个函数，如下所示：

static void WriteToFile(RozhraniWSDL.StandardniUcetType std, StreamWriter file) {
    ...
}
static void WriteToFile(RozhraniWSDL.NestandardniUcetType nstd, StreamWriter file) {
    ...
}

现在改变你的循环如下：

for (int x = 0; x <= 3; x++) {
    dynamic item = info.zverejneneUcty[x].Item;
    WriteToFile(item, file2); // <<== Magic
}
于 2013-09-19T12:50:16.393 回答
1

在数组上使用 OfType 扩展方法将过滤您需要的类型

foreach (var item in info.zverejneneUcty.OfType<RozhraniWSDL.StandardniUcetType>())
{
  file2.WriteLine(item.predcislo + "-" + item.cislo + "-" + item.kodBanky);
}
于 2013-09-19T12:49:54.523 回答
1

我将通过抽象类重新设计类型并删除问题，如下所示：

// I'm making up the inner types, adapt this to your code
public abstract class UcetType
{
    public virtual object predcislo { get; set; }
    public virtual object cislo { get; set; }
    public virtual object kodBanky { get; set; }

    public virtual void WriteToFile(StreamWriter file) 
    { 
        // build the string and write it to the file
        // considering all properties
        // this acts as "default" for this type and all derived ones
    }
}

public class StandardniUcetType : UcetType
{
    // This will use the abstract as-is
    // with all 3 properties and the "default" WriteToFile() method
}

public class NestandardniUcetType : UcetType
{
    /// <summary>
    /// Attempting to use this will throw an exception
    /// </summary>
    public override object predcislo
    {
        get { throw new NotSupportedException(); }
        set { throw new NotSupportedException(); }
    }
    /// <summary>
    /// Attempting to use this will throw an exception
    /// </summary>
    public override object kodBanky
    {
        get { throw new NotSupportedException(); }
        set { throw new NotSupportedException(); }
    }

    // change the way WriteToFile behaves
    public override void WriteToFile(StreamWriter file)
    {
        // build the string and write it to the file
        // only considering 'cislo' property
    }
}

// Usage example, based on question
for (int i = 0; i < dic_vystup.Length; i++)
{
    RozhraniWSDL.InformaceOPlatciType info = dic_vystup[i];   

    // I assume "3" is the expected length of the array ? Change the for like this:
    for (int x = 0; x <= info.zverejneneUcty.Length; x++)
    {   
        //Delegate to the WriteToFile() method the task to build and write the line!
        info.zverejneneUcty[x].Item.WriteToFile(file2);
    }
}

我认为dynamic这里的方法没有任何好处。这更具可读性并且将来易于扩展（需要一个新类型？只需派生UcetType一个新类并覆盖掉）。

于 2013-09-19T13:18:03.967 回答