Getting CheckBoxList Item values

问题:

I have a CheckBoxList which I'm populating with data. When I attempt to retrieve the checked items from the list I can only grab the item ordinal, I cannot get the value.

I've read that you can use Items[i].Value however when I try to do this I get an error stating that there is no extension method 'value'.

Here's the code I'm using to try and grab the information (note the GetItemText(i) actually only gives me the item position, not the text for the item)

   private void btnGO_Click(object sender, EventArgs e)
{
    for (int i = 0; i < chBoxListTables.Items.Count; i++)
    {
        if (chBoxListTables.GetItemChecked(i))
        {
            string str = chBoxListTables.GetItemText(i);
            MessageBox.Show(str);

            //next line invalid extension method
            chBoxListTables.Items[i].value;
        }
    }
}

This is using .Net 4.0

Any thoughts would be appreciated...thanks

回答1:

This ended up being quite simple. chBoxListTables.Item[i] is a string value, and an explicit convert allowed it to be loaded into a variable. The following code works:

private void btnGO_Click(object sender, EventArgs e)
{
    for (int i = 0; i < chBoxListTables.Items.Count; i++)
    {
          if (chBoxListTables.GetItemChecked(i))
        {
            string str = (string)chBoxListTables.Items[i];
            MessageBox.Show(str);
        }
    }
}

回答2:

Try to use this.

        for (int i = 0; i < chBoxListTables.Items.Count; i++)
        {
            if (chBoxListTables.Items[i].Selected)
            {
                string str = chBoxListTables.Items[i].Text;
                MessageBox.Show(str);

                var itemValue = chBoxListTables.Items[i].Value;
            }
        }

The "V" should be in CAPS in Value.

Here is another code example used in WinForm app and runs properly.

        var chBoxList= new CheckedListBox();
        chBoxList.Items.Add(new ListItem("One", "1"));
        chBoxList.Items.Add(new ListItem("Two", "2"));
        chBoxList.SetItemChecked(1, true);

        var checkedItems = chBoxList.CheckedItems;
        var chkText = ((ListItem)checkedItems[0]).Text;
        var chkValue = ((ListItem)checkedItems[0]).Value;
        MessageBox.Show(chkText);
        MessageBox.Show(chkValue);

回答3:

to get the items checked you can use CheckedItems or GetItemsChecked. I tried below code in .NET 4.5

Iterate through the CheckedItems collection. This will give you the item number in the list of checked items, not the overall list. So if the first item in the list is not checked and the second item is checked, the code below will display text like Checked Item 1 = MyListItem2.

//Determine if there are any items checked. 
if(chBoxListTables.CheckedItems.Count != 0)  
{
    //looped through all checked items and show results.
    string s = "";
    for (int x = 0; x < chBoxListTables.CheckedItems.Count; x++)
    {
        s = s + (x + 1).ToString() + " = " + chBoxListTables.CheckedItems[x].ToString()+ ", ";
    }
    MessageBox.Show(s);//show result
}

-OR-

Step through the Items collection and call the GetItemChecked method for each item. This will give you the item number in the overall list, so if the first item in the list is not checked and the second item is checked, it will display something like Item 2 = MyListItem2.

int i;  
string s;   
s = "Checked items:\n" ;  
for (i = 0; i < checkedListBox1.Items.Count; i++)  
{  
   if (checkedListBox1.GetItemChecked(i))  
   {  
      s = s + "Item " + (i+1).ToString() + " = " + checkedListBox1.Items[i].ToString() + "\n";  
   }  
}  
MessageBox.Show (s);

Hope this helps...

回答4:

//Simple example code:

foreach (var item in YourCheckedListBox.CheckedItems)
{List<string>.Add(item);}

回答5:

You can try this:-

string values = "";
foreach(ListItem item in myCBL.Items){
if(item.Selected)
{
values += item.Value.ToString() + ",";  
}
}
values = values.TrimEnd(',');  //To eliminate comma in last.

回答6:

Instead of this:

CheckboxList1.Items[i].value;

Try This:

CheckboxList1.Items[i].ToString();

It worked for me :)

回答7:

Try to use this :

 private void button1_Click(object sender, EventArgs e)
    {

        for (int i = 0; i < chBoxListTables.Items.Count; i++)
            if (chBoxListTables.GetItemCheckState(i) == CheckState.Checked)
            {
               txtBx.text += chBoxListTables.Items[i].ToString() + " \n"; 

            }
    }

回答8:

You can initialize a list of string and add those items that are selected.

Please check code, works fine for me.

List<string> modules = new List<string>();

foreach(ListItem s in chk_modules.Items)
{
    if (s.Selected)
    {
         modules.Add(s.Value);
    }
}