CODEWITHSUNDEEP
c#winformsvisual-studio-2010
user1112847
user1112847

Reputation: 297

Event handler logic in winforms for having one checkedbox selected at a time

    namespace explorer
    {
        public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
                DirectoryInfo di = new DirectoryInfo("c:\\test");
                FileSystemInfo[] files = di.GetFileSystemInfos();
                checkedListBox1.Items.AddRange(files);
            }

            private void checkedListBox1_ItemCheck(object sender, ItemCheckEventArgs e)
            {
                for (int ix = 0; ix < checkedListBox1.Items.Count; ++ix)
                if (ix != e.Index) checkedListBox1.SetItemChecked(ix, false); 
            }
            //removed irrelevant parts of the code
        }
    }

I forgot how to build an event handler for the checkedlistbox. I need one selected. I have multiple files but I need just one selected by a check box.

Upvotes: 0

Views: 167

Answers (2)

LarsTech
LarsTech

Reputation: 81675

You need to turn off the event handler or use a variable as a flag to avoid a stack overflow since you are unchecking items in an ItemCheck event:

private void checkedListBox1_ItemCheck(object sender, ItemCheckEventArgs e) {
  checkedListBox1.ItemCheck -= checkedListBox1_ItemCheck;
  for (int ix = 0; ix < checkedListBox1.Items.Count; ++ix) {
    if (ix != e.Index) {
      checkedListBox1.SetItemChecked(ix, false);
    }
  }
  checkedListBox1.ItemCheck += checkedListBox1_ItemCheck;
}

An example using a variable:

bool checkFlag = false;

private void checkedListBox1_ItemCheck(object sender, ItemCheckEventArgs e) {
  if (!checkFlag) {
    checkFlag = true;
    for (int ix = 0; ix < checkedListBox1.Items.Count; ++ix) {
      if (ix != e.Index) {
        checkedListBox1.SetItemChecked(ix, false);
      }
    }
    checkFlag = false;
  }
}

Upvotes: 2

0x49D1
0x49D1

Reputation: 8704

You can create List<FileSystemInfo> collection and add every checked file to it on check and remove on uncheck. The handler itself is already created as i see(checkedListBox1_ItemCheck). May be you should consider to write the question more clearly, because may be i understood you not exactly right?

Upvotes: 1

Related Questions