How to display shortcuts error on ErrorProvider1 '

The ErrorProvider component is very inconvenient to use effectively. However this is a fix, I will give an example in C # that extends the component with some new features:

• ShowError (Control ctl, bool enable) displays the text you entered at design time when the enable argument is true. An easy to use version of SetError ().
• HasErrors returns true if all active warning icons are displayed. Conveniently in your OK button. Click event handler.
• FocusError () sets focus to the first control that has a warning icon, if any. It returns false if there are no warnings left.
• SetError () is a replacement for ErrorProvider.SetError (). You only need it if you add any controls after the Load Event is fired, or if you need to change the alert text.

Add a new class to your project and paste the code shown below. Compilation. Remove it from the top of the toolbar onto the form. Design-time behavior is identical. Modestly tested.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Windows.Forms;
using System.ComponentModel.Design;

class MyErrorProvider : ErrorProvider {
    public void ShowError(Control ctl, bool enable) {
        // Easy to use version of SetError(), uses design-time text
        if (!enable) base.SetError(ctl, "");
        else {
            if (errors.ContainsKey(ctl)) base.SetError(ctl, errors[ctl]);
            else base.SetError(ctl, "No error text available");
        }
    }

    public bool HasErrors {
        // True if any errors are present
        get {
            foreach (var err in errors)
                if (!string.IsNullOrEmpty(base.GetError(err.Key))) return true;
            return false;
        }
    }

    public bool FocusError() {
        // Set the focus to the first control with an active error
        foreach (var err in errors) {
            if (!string.IsNullOrEmpty(base.GetError(err.Key))) {
                err.Key.Focus();
                return true;
            }
        }
        return false;
    }

    public new void SetError(Control ctl, string text) {
        // Use this only to add/modify error text after the form Load event
        if (!string.IsNullOrEmpty(text)) {
            if (errors.ContainsKey(ctl)) errors[ctl] = text;
            else errors.Add(ctl, text);
        }
        base.SetError(ctl, text);
    }

    private void initialize(object sender, EventArgs e) {
        // Preserve error text
        copyErrors(((Form)sender).Controls);
    }
    private void copyErrors(Control.ControlCollection ctls) {
        foreach (Control ctl in ctls) {
            var text = this.GetError(ctl);
            if (!string.IsNullOrEmpty(text)) {
                errors.Add(ctl, text);
                base.SetError(ctl, "");
            }
            copyErrors(ctl.Controls);
        }
    }

    private Dictionary<Control, string> errors = new Dictionary<Control, string>();

    // Plumbing to hook the form Load event
    [Browsable(false)]
    public new ContainerControl ContainerControl {
        get { return base.ContainerControl; }
        set {
            if (base.ContainerControl == null) {
                var form = value.FindForm();
                if (form != null) form.Load += initialize;
            }
            base.ContainerControl = value;
        }
    }

    public override ISite Site {
        set {
            // Runs at design time, ensures designer initializes ContainerControl
            base.Site = value;
            if (value == null) return;
            IDesignerHost service = value.GetService(typeof(IDesignerHost)) as IDesignerHost;
            if (service == null) return;
            IComponent rootComponent = service.RootComponent;
            this.ContainerControl = rootComponent as ContainerControl;
        }
    }
}