Question

在form_load事件中，我创建了三个复选框。然后使用button_click事件我想检查复选框的状态，但它们在我的if语句中不可用。我发现这段代码是一个例子：

CheckBox chk = new CheckBox();
chk.Top = 50;
chk.Left = 50;
chk.Text = "Check Box Test";
chk.Name = "chkTest";
this.Controls.Add(chk);
CheckBox chkTest = (CheckBox)Controls["chkTest"];

仅当我检查form_load内的状态时才有效。如何使用button_click访问复选框？

Answer 1

一个选项是在类级别创建一个List<CheckBox>来保存您创建的复选框的集合。

示例：

List<CheckBox> CheckBoxes = new List<CheckBox>();
public Form1()
{
    InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{
    CreateCheckBoxes();
}

private void CreateCheckBoxes()
{
    //Create 3 checkboxes
    int intialTop = 50;
    for (int i = 0; i < 3; i++)
    {
        CheckBox chk = new CheckBox();
        chk.Top = intialTop;
        chk.Left = 50;
        chk.Text = "Check Box Test";
        chk.Name = "chkTest";
        this.Controls.Add(chk);
        CheckBoxes.Add(chk);

        intialTop += 20;
    }

    //You can access your checkboxes anywhere in Form1 now.
    var first = CheckBoxes.First();
    first.Text = "First Checkbox";
}

附加示例：

此示例显示向表单添加两个复选框，并为其提供自己的单击事件处理程序。

CheckBox checkBoxA;
CheckBox checkBoxB;

public Form1()
{
    InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{
    //Add checkbox A
    checkBoxA = new CheckBox();
    checkBoxA.Top = 10;
    checkBoxA.Left = 50;
    checkBoxA.Text = "CheckBoxA";
    //Register the event handler for this checkbox
    checkBoxA.Click += new EventHandler(checkBoxA_Click);
    this.Controls.Add(checkBoxA);

    //Add checkbox B
    checkBoxB = new CheckBox();
    checkBoxB.Top = 30;
    checkBoxB.Left = 50;
    checkBoxB.Text = "checkBoxB";
    //Register the event handler for this checkbox
    checkBoxB.Click += new EventHandler(checkBoxB_Click);
    this.Controls.Add(checkBoxB);        
}

void checkBoxA_Click(object sender, EventArgs e)
{
    MessageBox.Show("CheckBoxA has been clicked!!!");
}

void checkBoxB_Click(object sender, EventArgs e)
{
    MessageBox.Show("CheckBoxB has been clicked!!!");
}

Answer 2

如前所述，您可以创建一个类级CheckBox，然后在代码中的任何位置进行检查：

CheckBox checkBox1 = new CheckBox();
private void Form1_Load()
{
   checkBox1.Name = "CheckBox1";
   checkBox1.Text = "Click Me!";
   checkBox1.Click += new EventHandler(checkBox1_Click);   // Only need this if you want a click handler
   this.Controls.Add(checkBox1);
}

private void checkBox1_Click(object sender, EventArgs e)
{
   MessageBox.Show("You click the check box");
}

private void submitButton_Click(object sender, EventArgs e)
{
   if (checkBox1.Checked)
   {
      MessageBox.Show("Check box is checked!");
   }
}

或者，您可以遍历表单的控件并搜索那里的复选框：

private void CheckCheckBoxes(string checkBoxName)
{
   // this.Controls is a collection of all controls on the form (assuming this is run on the Form class)
   foreach(Control control in this.Controls)
   {
      if (control.Name == checkBoxName && control is CheckBox)
      {
         CheckBox checkBox = control as CheckBox;
         if (checkBox.Checked)
         {
            MessageBox.Show("Check box is checked");
         }
      }
   }
}

如何在Windows窗体中访问动态创建的复选框

2 个答案: