如何禁用form2组合框基于form1组合框值？ [英] How to disable form2 combo boxes based on form1 combo box value?

问题描述

我试图在窗体2中禁用一些组合框。如果comboxbox的值为0
禁用表单2中的某些组合框

我在form1中做了什么

  public partial class Form1：Form 
 {
 public Form1（）
 {
 InitializeComponent（）; 
} 
 
 public ComboBox combo 
 {
 get {return dropdown; } 
} 
  

到目前为止形式2

  private void Form2_Load（object sender，EventArgs e）
 {
 Form1 f = new Form1（）; 
 if（f.combo.SelectedIndex == 0）
 {
 comboBox1.Enabled = false; 
} 
  

这不工作，我不能排序（新到c＃）

解决方案

如果使用以下语法在Form中创建Form1：

  Form1 f = new Form1（）; 
  

您将获得Form1（或copy）的新实例，而不是已经打开的实例。您需要将Form1的引用传递给Form2。


将此代码添加到Form2中：

  private Form1 myParentForm; 
 public Form2（Form1 parentForm）
 {
 myParentForm = parentForm; 
} 
  

然后你可以通过变量myParentForm使用Form1。像这样：

  private void Form2_Load（object sender，EventArgs e）
 {
 if（myParentForm。 combo.SelectedIndex == 0）
 {
 comboBox1.Enabled = false; 
} 
} 
  

在Form1中有一个类似这样的代码： / p>

  Form2 mySecondForm = new Form2（）; 
  

更改为：

  form2 mySecondForm = new Form2（this）; 
  

I am trying to disable some of the combo boxes in form 2 based in form 1 selected value.

Lets say In Form1 if comboxbox value is 0 Disable certain combo boxes in form 2

What I have done in form1

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    public ComboBox combo
    {
        get { return dropdown; } 
    }

and in form 2 so far

private void Form2_Load(object sender, EventArgs e)
{
  Form1 f = new Form1();
  if (f.combo.SelectedIndex == 0)
  {
    comboBox1.Enabled = false;
  }

This is not working and I cant sort it out (new to c#)

解决方案

If you create Form1 at Form with this syntax:

  Form1 f = new Form1();

You will get new instance of Form1 (or "copy"), not the one thats already open. You need to pass the reference of Form1 to Form2.

Put this code into Form2:

private Form1 myParentForm;
public Form2(Form1 parentForm)
{
  myParentForm = parentForm;
}

Then you can use Form1 through a variable myParentForm. Like this:

private void Form2_Load(object sender, EventArgs e)
{
  if (myParentForm.combo.SelectedIndex == 0)
  {
    comboBox1.Enabled = false;
  }
}

In Form1 you have a code something like this:

Form2 mySecondForm = new Form2();

change that to:

Form2 mySecondForm = new Form2(this);

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