如何访问WinForm应用程序中的对象数组以显示在文本框中？ [英] How to access array of objects in a WinForm app for display in a textbox?

问题描述

首先感谢你花时间阅读，我知道我是N00B，但代码中丢失了N00B。这是一个学校作业，我可以在控制台应用程序中，因为它的工作原理，但我想在WinForm应用程序中看起来很漂亮。



核心问题我需要使用LINQ来查询和显示基于过滤器的对象集合，我可以在控制台应用程序中执行此操作。



当我试图让它在Winform中看起来很漂亮时，这个数组无法通过按钮点击事件访问。很确定我只是以错误的方式创建对象。我吮吸WinForm应用程序。



::我的命名空间全部匹配。

::此代码将在consol中正确运行LINQ查询，所以我知道var sortDescription ..可能很好。



首先有这个代码创建我的对象数组：

 {
  public   partial   class  DisplayForm：Form 
 {
  public  DisplayForm（）
 {
 InitializeComponent（）; 
 QueryClass QClasses =  new  QueryClass（）; 
 Invoice [] invoiceItems =  new 发​​票[ 8 ]; 
 invoiceItems [ 0 ] =  new 发​​票（ 83 ， 电动砂光机， 7 ， 57  .98M）; 
 invoiceItems [ 1 ] =  new 发​​票（ 24 ，  Power Saw， 18 ， 99  .99M）; 
 invoiceItems [ 2 ] =  new 发​​票（ 7 ， 大锤， 11 ， 21  .50M）; 
 invoiceItems [ 3 ] =  new 发​​票（ 77 ，  Hammer， 76 ， 11  .99M）; 
 invoiceItems [ 4 ] =  new 发​​票（ 39 ， 割草机， 3 ， 79  .50M）; 
 invoiceItems [ 5 ] =  new 发​​票（ 68 ， 螺丝刀， 106 ， 6  .99M）; 
 invoiceItems [ 6 ] =  new 发​​票（ 56 ， 曲线锯， 21 ， 11  .00M）; 
 invoiceItems [ 7 ] =  new 发​​票（ 3 ， 扳手， 34 ， 7  .50M）; 
 
} 
 
  //  这是我的按钮点击代码 
  private   void  queryA_Click（ object  sender，EventArgs e）
 {
  var  sortDescription = 
  from 元素  invoiceItems 
  orderby  element.PartDescription 
 选择元素; 
 
  foreach （ var 元素 in  invoiceItems）
 {
 displayHere.AppendText（element.ToString（）+ Environment.NewLine）; 
} 
 
} 

....我在Publc DisplayFrom中试过这个（）阻止并创建我自己的块netiher作品。





现在错误和我的问题。

::在某些测试代码中，我使用它的工作方式，AppendText ......



::调用的ojbect invoiceItems位于initialzeComponent（）正下方的标准Winform public DisplayForm（）中。按钮对象无法看到对象''invoiceItems''。我猜这是因为两个对象的范围是我的问题。



::我试过在公共空类中创建我的对象数组但是也没有用（告诉你我是N00B）



如何获取Button Action中的对象以查看项目的instatiated数组对象？



最后，感谢任何帮助，我想提前感谢你。是的，我已经谷歌了几个小时并且放弃了所以我在外面除草。



Scott

解决方案

InvoiceItems数组变量仅在 DisplayForm（）过程中可见。

请阅读：范围（C＃） [ ^ ]

 QueryClass QClasses = new QueryClass（）; 
 Invoice [] invoiceItems = new Invoice [8]; 
 

在DisplayForm（）之外写这个;

范围有问题变量

 invoiceItem 

。

将其声明为类级变量。

currentlu这是<$ p的局部变量$ p> DisplayForm（）

我只想感谢Mr.Priyank（聪明的化名）和Maciej Los的帮助。当然问题解决了我希望我得到一个关于项目的A.



Scott

Thank you first for taking the time to read, I know I''m N00B but a N00B lost in code. This is a school assignment and I can turn in the console app, because it works, but I would like to make this look pretty in a WinForm app.

Core problem I need to use LINQ to query and display a collection of objects based on the filter, this I can do in a Console Appliction.

When I tried to make it look pretty in a Winform the array is not accessable from the buton click event. Pretty sure I am just creating the objects in the wrong way. I suck with WinForm apps.

:: My namespaces all match.
:: This code will correctly run the LINQ query in a consol so I know that the var sortDescription.. is probably good.

First there is this code which creates my array of objects:

{
  public partial class DisplayForm : Form
    {
        public DisplayForm()
        {
            InitializeComponent();
            QueryClass QClasses = new QueryClass();
            Invoice[] invoiceItems = new Invoice[8];
            invoiceItems[0] = new Invoice(83, "Electric sander", 7, 57.98M);
            invoiceItems[1] = new Invoice(24, "Power Saw", 18, 99.99M);
            invoiceItems[2] = new Invoice(7, "Sledge Hammer", 11, 21.50M);
            invoiceItems[3] = new Invoice(77, "Hammer", 76, 11.99M);
            invoiceItems[4] = new Invoice(39, "Lawn Mower", 3, 79.50M);
            invoiceItems[5] = new Invoice(68, "Screwdriver", 106, 6.99M);
            invoiceItems[6] = new Invoice(56, "Jig saw", 21, 11.00M);
            invoiceItems[7] = new Invoice(3, "Wrench", 34, 7.50M);

        }

//This is my button click code
private void queryA_Click(object sender, EventArgs e)
{
   var sortDescription =
    from element in invoiceItems
    orderby element.PartDescription
    select element;

   foreach (var element in invoiceItems)
    {
      displayHere.AppendText(element.ToString() + Environment.NewLine);
    }

}

.... I have tried this in both the Publc DisplayFrom() block and created my own block netiher works.


Now the error and my problem.
:: When in some test codes I utilize the method of display it works, the AppendText...

:: The ojbect called invoiceItems is in the standard Winform public DisplayForm() right below the initialzeComponent(). And the button object can''t see the object ''invoiceItems''. I am guessing it''s because the scope of the two objects is my problem.

:: I have tried creating my array of objects in a public void class but that didn''t work either (Told you I was a N00B)

How do I get the objects in the Button Action to see the instatiated array object of items?

Lastly, any help is appreciated and I want to thank you in advance. Yes I have been googleing for hours and gave up so I am outside weeding.

Scott

解决方案

InvoiceItems array variable is visible only inside DisplayForm() procedure.
Please, read about: Scopes (C#)[^]

QueryClass QClasses = new QueryClass();
           Invoice[] invoiceItems = new Invoice[8];

write this outside the DisplayForm();
There is a problem with scope of the variable

invoiceItem

.
Declare it as a class level variable.
currentlu this is local variable to

DisplayForm()

I just want to thank both Mr.Priyank (clever pseudonym) and Maciej Los for the help. Of course problem resolved I hope I get an A on the project.

Scott

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