using System; using System.Drawing; using System.Collections; using System.ComponentModel; using System.Windows.Forms; using System.Data; public class ErrorForm : System.Windows.Forms.Form { private System.Windows.Forms.Label label1; private System.Windows.Forms.Button btnValidate; private System.Windows.Forms.ErrorProvider errorProvider1; private System.Windows.Forms.TextBox txtInput; public ErrorForm() { InitializeComponent(); CenterToScreen(); } private void InitializeComponent() { this.errorProvider1 = new System.Windows.Forms.ErrorProvider(); this.label1 = new System.Windows.Forms.Label(); this.txtInput = new System.Windows.Forms.TextBox(); this.btnValidate = new System.Windows.Forms.Button(); this.SuspendLayout(); // // errorProvider1 // this.errorProvider1.BlinkRate = 500; this.errorProvider1.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.AlwaysBlink; // // label1 // this.label1.Location = new System.Drawing.Point(8, 8); this.label1.Name = "label1"; this.label1.Size = new System.Drawing.Size(376, 56); this.label1.TabIndex = 2; this.label1.Text = "The following text box only allows 5 characters."; // // txtInput // this.txtInput.Location = new System.Drawing.Point(144, 80); this.txtInput.Name = "txtInput"; this.txtInput.Size = new System.Drawing.Size(120, 20); this.txtInput.TabIndex = 0; this.txtInput.Text = ""; this.txtInput.Validating += new System.ComponentModel.CancelEventHandler(this.txtInput_Validating); // // btnValidate // this.btnValidate.Location = new System.Drawing.Point(16, 72); this.btnValidate.Name = "btnValidate"; this.btnValidate.Size = new System.Drawing.Size(112, 32); this.btnValidate.TabIndex = 1; this.btnValidate.Text = "OK"; // // ErrorForm // this.AutoScaleBaseSize = new System.Drawing.Size(5, 13); this.ClientSize = new System.Drawing.Size(400, 125); this.Controls.AddRange(new System.Windows.Forms.Control[] { this.label1, this.btnValidate, this.txtInput}); this.Name = "ErrorForm"; this.Text = "Error Trapper"; this.ResumeLayout(false); } static void Main() { Application.Run(new ErrorForm()); } private void txtInput_Validating(object sender, System.ComponentModel.CancelEventArgs e) { if(txtInput.Text.ToString().Length > 5) { errorProvider1.SetError( txtInput, "Can't be greater than 5!"); } else{ errorProvider1.SetError(txtInput, ""); } } }