10 check-boxes multiple combinations in c#

问题

How do I loop through without writing a million if statements? Here's a sample of the code I have it wrong as it will only check each box and then move on to the next. Forgot to say that all ten check boxes are in a panel and they need to be check in any combination. I don't want to write heaps of && or || I cant even count the combinations Please help me.

if (cbxTitle.Checked == true)
{
      searched = "title";
}
else if (cbxAuthor.Checked == true)
{
      searched = "author";
}
else if (cbxYear.Checked == true)
{
      searched = "year";
}
else if (cbxWeight.Checked == true)
{
      searched = "weight";
}

回答1:

It seems you want to include all search conditions selected by the user. If you didn't, then I'd definitely use radio buttons.

To avoid endless if/else statements, I'd use a foreach loop on all CheckBox controls, and--assuming you've been consistent in your variable names--you could then use a substring of the name to be appended to your search criteria.

So your algorithm would be more or less:

• get a list of all controls of type Checkbox
• for each control found, if it is Checked, extract its name
• obtain the search criterion represented by this control by removing the 'cbx' prefix
• append this criterion to your 'searched' string

EDIT:

At your request, I'm adding a sample.

Since it's a search application, I thought you would have a "Search Options" form.

Here's the section that initializes this form.

namespace SearchApplication
{
    using System.Collections.Generic;
    using System.Linq;
    using System.Windows.Forms;

    public partial class SearchOptionsForm : Form
    {
        // prefix you used for all your checkboxes
        private const string prefix = @"cbx";

        // store *all* checkboxes in your form
        // if you had other checkboxes in your form, 
        // you would need to think how you would want to differentiate them
        private IEnumerable<CheckBox> searchOptionControls;

        // represents all choices made by the user to customize the search type
        private string searched;

        // since your 'searched' variable is a string, 
        // you need a filter separator to be able to tell user selections apart
        private const string optionSeparator = @";";

        public SearchOptionsForm()
        {
            this.InitializeComponent();

            // initialize your collection of checkboxes
            this.searchOptionControls = this.Controls.OfType<CheckBox>();
        }
    }
}

And here's the code that reacts to the user input, after she clicks "Apply"

namespace SearchApplication
{
    using System;
    using System.Windows.Forms;

    public partial class SearchOptionsForm : Form
    {
        /// <summary>
        /// Updates the 'searched' string with the selections made by the user.
        /// </summary>
        /// <param name="sender">The 'Apply' button.</param>
        /// <param name="e">Not used in this implementation.</param>
        private void ApplyClicked(object sender, EventArgs e)
        {
            // reset your filter after every click
            this.searched = string.Empty;

            // inspect all controls of interest
            foreach (var currentOption in this.searchOptionControls)
            {
                // determine if user wants to use this filter 
                if (currentOption.Checked)
                {
                    // append to your existing search options
                    searched += currentOption.Name.Substring(prefix.Length);

                    // include the filter separator
                    searched += optionSeparator;
                }
            }

            // note that filter order in the string doesn't match display order
            this.textBoxSearchFilters.Text = searched;
        }
    }
}

回答2:

You can replace your if statements with:

searched = this.Controls
       .OfType<CheckBox>()
       .First(x => x.Checked).Name.Substring(3).ToLower();

This assumes three things:

1. You have at least one checked CheckBox
2. Your checkboxes are direct child element of your Form, they are not inside of a Panel or some other container
3. Name of your checkbox (without cbx prefix) is the value that you want assign to searched.

Also don't forget to include System.Linq namespace with a using directive in order to use LINQ methods (OfType and First)

回答3:

You must subscribe on the CheckedChange event of each checkbox.

When a checkbox is checked, take action for your search.

来源：https://stackoverflow.com/questions/23900873/10-check-boxes-multiple-combinations-in-c-sharp