WinForm IP地址输入框控件实现

 using System; using System.Collections.Generic; using System.ComponentModel; using System.Drawing; using System.Data; using System.Text; using System.Windows.Forms; using System.Text.RegularExpressions; namespace IPInputControl.Ctrl { public partial class IPInput : UserControl { public IPInput() { InitializeComponent(); } TextBox ParentTxt; private void IPInput_Load(object sender, EventArgs e) { ParentTxt = txt_1; } public void txt_KeyDown(object sender, KeyEventArgs e) { ParentTxt = (TextBox)sender; if (e.KeyCode == Keys.Left) { switch (ParentTxt.Name.Split('_')[1]) { case "1": break; case "2": if (ParentTxt.SelectionStart == 0 && ParentTxt.Text != "") { if (int.Parse(ParentTxt.Text) > 255) { MessageBox.Show(ParentTxt.Text + "不是有效项。请指定一个介于1和255之间的值。", "错误", MessageBoxButtons.OK, MessageBoxIcon.Warning); ParentTxt.Text = "255"; ParentTxt.SelectionStart = 0; } else { txt_1.Focus(); } } else if (ParentTxt.Text == "") { txt_1.Focus(); } break; case "3": if (ParentTxt.SelectionStart == 0 && ParentTxt.Text != "") { if (int.Parse(ParentTxt.Text) > 255) { MessageBox.Show(ParentTxt.Text + "不是有效项。请指定一个介于1和255之间的值。", "错误", MessageBoxButtons.OK, MessageBoxIcon.Warning); ParentTxt.Text = "255"; ParentTxt.SelectionStart = 0; } else { txt_2.Focus(); } } else if (ParentTxt.Text == "") { txt_2.Focus(); } break; case "4": if (ParentTxt.SelectionStart == 0 && ParentTxt.Text != "") { if (int.Parse(ParentTxt.Text) > 255) { MessageBox.Show(ParentTxt.Text + "不是有效项。请指定一个介于1和255之间的值。", "错误", MessageBoxButtons.OK, MessageBoxIcon.Warning); ParentTxt.Text = "255"; ParentTxt.SelectionStart = 0; } else { txt_3.Focus(); } } else if (ParentTxt.Text == "") { txt_3.Focus(); } break; } } else if (e.KeyCode == Keys.Right) { switch (ParentTxt.Name.Split('_')[1]) { case "1": if (ParentTxt.SelectionStart == ParentTxt.Text.Length && ParentTxt.Text != "") { if (int.Parse(ParentTxt.Text) > 223) { MessageBox.Show(ParentTxt.Text + "不是有效项。请指定一个介于1和223之间的值。", "错误", MessageBoxButtons.OK, MessageBoxIcon.Warning); ParentTxt.Text = "223"; ParentTxt.SelectionStart = ParentTxt.Text.Length; } else { txt_2.Focus(); } } else if (ParentTxt.Text == "") { txt_2.Focus(); } break; case "2": if (ParentTxt.SelectionStart == ParentTxt.Text.Length && ParentTxt.Text != "") { if (int.Parse(ParentTxt.Text) > 255) { MessageBox.Show(ParentTxt.Text + "不是有效项。请指定一个介于1和255之间的值。", "错误", MessageBoxButtons.OK, MessageBoxIcon.Warning); ParentTxt.Text = "255"; ParentTxt.SelectionStart = ParentTxt.Text.Length; } else { txt_3.Focus(); } } else if (ParentTxt.Text == "") { txt_3.Focus(); } break; case "3": if (ParentTxt.SelectionStart == ParentTxt.Text.Length && ParentTxt.Text != "") { if (int.Parse(ParentTxt.Text) > 255) { MessageBox.Show(ParentTxt.Text + "不是有效项。请指定一个介于1和255之间的值。", "错误", MessageBoxButtons.OK, MessageBoxIcon.Warning); ParentTxt.Text = "255"; ParentTxt.SelectionStart = ParentTxt.Text.Length; } else { txt_4.Focus(); } } else if (ParentTxt.Text == "") { txt_4.Focus(); } break; case "4": break; } } } public void txt_KeyPress(object sender, KeyPressEventArgs e) { ParentTxt = (TextBox)sender; Regex regex = new Regex(@"^[0-9]+$"); if (!regex.IsMatch(e.KeyChar.ToString()) && e.KeyChar != (Char)Keys.Back) { e.Handled = true; } else if (e.KeyChar == (Char)Keys.Back) { e.Handled = false; switch (ParentTxt.Name.Split('_')[1]) { case "1": break; case "2": if (ParentTxt.SelectionStart == 0) { txt_1.Focus(); if (txt_1.Text != "") { txt_1.Text = txt_1.Text.Substring(0, txt_1.Text.Length - 1); } txt_1.SelectionStart = txt_1.Text.Length; } break; case "3": if (ParentTxt.SelectionStart == 0) { txt_2.Focus(); if (txt_2.Text != "") { txt_2.Text = txt_2.Text.Substring(0, txt_2.Text.Length - 1); } txt_2.SelectionStart = txt_2.Text.Length; } break; case "4": if (ParentTxt.SelectionStart == 0) { txt_3.Focus(); if (txt_3.Text != "") { txt_3.Text = txt_3.Text.Substring(0, txt_3.Text.Length - 1); } txt_3.SelectionStart = txt_3.Text.Length; } break; } } else { switch (ParentTxt.Name.Split('_')[1]) { case "1": if (ParentTxt.SelectionStart == ParentTxt.Text.Length) { if (int.Parse(ParentTxt.Text + e.KeyChar.ToString()) > 223) { MessageBox.Show(ParentTxt.Text + e.KeyChar.ToString() + "不是有效项。请指定一个介于1和223之间的值。", "错误", MessageBoxButtons.OK, MessageBoxIcon.Warning); e.Handled = true; ParentTxt.Text = "223"; } else { e.Handled = false; } } else if(ParentTxt.Text.Length != 3) { e.Handled = false; } else { e.Handled = true; } break; default: if (ParentTxt.SelectionStart == ParentTxt.Text.Length) { if (int.Parse(ParentTxt.Text + e.KeyChar.ToString()) > 255) { MessageBox.Show(ParentTxt.Text + e.KeyChar.ToString() + "不是有效项。请指定一个介于1和255之间的值。", "错误", MessageBoxButtons.OK, MessageBoxIcon.Warning); e.Handled = true; ParentTxt.Text = "255"; } else { e.Handled = false; } } else if (ParentTxt.Text.Length != 3) { e.Handled = false; } else { e.Handled = true; } break; } } } public void txt_TextChanged(object sender, EventArgs e) { if (ParentTxt.Text.Length == 3) { switch (ParentTxt.Name.Split('_')[1]) { case "1": if (ParentTxt.SelectionStart == ParentTxt.Text.Length) { txt_2.Focus(); } break; case "2": if (ParentTxt.SelectionStart == ParentTxt.Text.Length) { txt_3.Focus(); } break; case "3": if (ParentTxt.SelectionStart == ParentTxt.Text.Length) { txt_4.Focus(); } break; case "4": break; } } } } } 

 using System; using System.Collections.Generic; using System.ComponentModel; using System.Drawing; using System.Data; using System.Text; using System.Windows.Forms; using System.Text.RegularExpressions; namespace IPInputControl.Ctrl { public partial class ControlText : TextBox { public ControlText() { InitializeComponent(); } public void txt_TextChange(object sender, EventArgs e) { if (this.Text.Length == 3) { SendKeys.Send("{TAB}"); } } protected override bool ProcessCmdKey(ref Message msg, Keys keyData) { if (keyData == Keys.Tab) { return true; } return base.ProcessCmdKey(ref msg, keyData); } } }