在Winfrom下实现类似百度、Google搜索自能提示功能

前记：数据源来自页面的一个ComboBox的数据源List<Contract>集合

页面放置一个TextBox(搜索框)、ListBox（显示搜索出来的数据），ListBox位置位于TextBox正下方，初始化隐藏。

TextBox--->txtSearch  ListBox--->listBox1关于两个控件的事件，详见代码：

#region 自能提示 Point pList = new Point(); private void txtSearch_TextChanged(object sender, EventArgs e) { if (this.txtSearch.Text.Trim() != "") { List<Contract> source = getDataTable(this.txtSearch.Text.Trim()); BindList(source); this.listBox1.Visible = true; } else { this.listBox1.Items.Clear(); this.listBox1.Visible = false; } } private void txtSearch_KeyDown(object sender, KeyEventArgs e) { if (e.KeyCode == Keys.Down && this.listBox1.Visible) { this.listBox1.Focus(); if (this.listBox1.SelectedItems.Count > 0) { this.listBox1.SetSelected(this.listBox1.SelectedIndex, false); } if (this.listBox1.Items.Count > 0) { this.listBox1.SetSelected(0, true); } } } private void listBox1_MouseUp(object sender, MouseEventArgs e) { if (this.listBox1.SelectedItems.Count > 0) { this.txtSearch.Text = this.listBox1.Text; cboChoCont.Text = this.txtSearch.Text; this.listBox1.Visible = false; this.txtSearch.Focus(); } } private void listBox1_MouseMove(object sender, MouseEventArgs e) { Point m = new Point(e.X, e.Y); int index = GetItemAt(this.listBox1, e.X, e.Y); if (this.listBox1.SelectedItems.Count > 0 && this.listBox1.SelectedIndex != index) { this.listBox1.SetSelected(this.listBox1.SelectedIndex, false); } if (index != -1 && this.listBox1.SelectedIndex != index) { this.listBox1.SetSelected(index, true); } } private void listBox1_KeyDown(object sender, KeyEventArgs e) { if (e.KeyCode == Keys.Enter && this.listBox1.Visible && this.listBox1.SelectedItems.Count > 0) { this.txtSearch.Text = this.listBox1.SelectedItems[0].ToString(); this.cboChoCont.Text = this.txtSearch.Text; this.listBox1.Visible = false; this.txtSearch.Focus(); } } private bool GetItemAt(Point Mousep, int index) { int ph = this.listBox1.GetItemHeight(index) * index; int ph1 = this.listBox1.GetItemHeight(index) * index + this.listBox1.GetItemHeight(index); if (Mousep.Y > ph && Mousep.Y < ph1 && Mousep.X > 0 && Mousep.X < this.listBox1.Width) { return true; } else { return false; } } private int GetItemAt(ListBox listBox, int X, int Y) { int index = -1; for (int i = 0; i < listBox.Items.Count; i++) { System.Drawing.Rectangle r = listBox.GetItemRectangle(i); if (r.Contains(new Point(X, Y))) { index = i; ; break; } } return index; } private void BindList(List<Contract> source) { this.listBox1.Items.Clear(); for (int i = 0; i < source.Count; i++) { this.listBox1.Items.Add(source[i].Con_Name_Serial); } if (source.Count < 11) { this.listBox1.Height = 15 * source.Count + 15; } else { this.listBox1.Height = 150; } this.listBox1.Visible = true; } private List<Contract> getDataTable(string s) { List<Contract> searchList = new List<Contract>(); int length = list.Count; for (int i = 0; i < length; i++) { if (list[i].Con_Name_Serial.IndexOf(s) == 0) searchList.Add(list[i]); } return searchList; } private void listBox1_DrawItem(object sender, DrawItemEventArgs e) { // Set the DrawMode property to draw fixed sized items. listBox1.DrawMode = DrawMode.OwnerDrawFixed; // Draw the background of the ListBox control for each item. e.DrawBackground(); // Define the default color of the brush as black. Brush myBrush = Brushes.Black; FontFamily fontFamily = new FontFamily("宋体"); System.Drawing.Font myFont = new Font(fontFamily, 9); // Determine the color of the brush to draw each item based on the index of the item to draw. if((e.State & DrawItemState.Selected) == DrawItemState.Selected) { //e.Graphics.FillRectangle(Brushes.Blue, e.Bounds); if(e.Index > -1) { e.Graphics.DrawString(listBox1.Items[e.Index].ToString(), myFont, Brushes.White, e.Bounds, StringFormat.GenericDefault); } } else { //e.Graphics.FillRectangle(Brushes.White, e.Bounds); if(e.Index > -1) { e.Graphics.DrawString(listBox1.Items[e.Index].ToString(), myFont, myBrush, e.Bounds, StringFormat.GenericDefault); } } // Draw the current item text based on the current Font and the custom brush settings. //e.Graphics.DrawString(listBox1.Items[e.Index].ToString(), e.Font, myBrush, e.Bounds, StringFormat.GenericDefault); // If the ListBox has focus, draw a focus rectangle around the selected item. e.DrawFocusRectangle(); } #endregion