实例介绍
【实例简介】
【实例截图】
【核心代码】
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Drawing;
using System.Diagnostics;
using System.Windows.Forms;
namespace xComboBox
{
public class PowerComboBox : ComboBox
{
//APIs
//TODO: INSTANT C# TODO TASK: Insert the following converted event handlers at the end of the 'InitializeComponent' method for forms, 'Page_Init' for web pages, or into a constructor for other classes:
[System.Runtime.InteropServices.DllImport("user32.dll")]
private extern static int SendMessage(System.IntPtr hWnd, int Msg, System.Int32 wParam, System.IntPtr lParam);
//properties
private string mDividerFormat = "";
private Color mGroupColor = System.Drawing.SystemColors.WindowText; //ForeColor 'mediumblue
private bool[] mItemsChecks;
private bool mCheckBoxes;
private Color mGridColor = Color.FromArgb(240, 248, 255);
//vars - last selected item
private bool mRedrawingUnselected;
private Graphics mGraphics;
private Rectangle mBounds;
private Int32 mIndex;
private char mItemSeparator1 = ',';
private char mItemSeparator2 = '&';
private Graphics mGraphics_t;
private Rectangle mBounds_t;
private Int32 mIndex_t;
private long mHoverIndex;
private Timer mTimer1;
//events
public delegate void ItemHoverEventHandler(Int32 eIndex);
public event ItemHoverEventHandler ItemHover;
//vars
private Int32 mLastSelectedIndex = -1;
//constructor
public PowerComboBox()
{
// set draw mode to owner draw
this.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed; //DrawMode.OwnerDrawFixed
}
//properties
[System.ComponentModel.Description("Use this property to set divider flag. Recommend you use three hyphens ---."), System.ComponentModel.Category("Power Properties")]
public string DividerFormat
{
get
{
return mDividerFormat;
}
set
{
mDividerFormat = value;
}
}
[System.ComponentModel.Description("Use this property to set the ForeColor of the grouping text."), System.ComponentModel.Category("Power Properties")]
public Color GroupColor
{
get
{
return mGroupColor;
}
set
{
mGroupColor = value;
}
}
[System.ComponentModel.Description("Use this property to set the BackColor of the grid."), System.ComponentModel.Category("Power Properties")]
public Color GridColor
{
get
{
return mGridColor;
}
set
{
mGridColor = value;
}
}
//ORIGINAL LINE: Public Property ItemsChecks(ByVal xIndex As Int32) As Boolean
//INSTANT C# NOTE: C# does not support parameterized properties - the following property has been divided into two methods:
[System.ComponentModel.Description("Use this property to get/set corresponding checkboc values."), System.ComponentModel.Category("Power Properties")]
public bool GetItemsChecks(Int32 xIndex)
{
return mItemsChecks[xIndex];
}
public void SetItemsChecks(Int32 xIndex, bool value)
{
mItemsChecks[xIndex] = value;
}
[System.ComponentModel.Description("Use this property to enable checkboxes."), System.ComponentModel.Category("Power Properties")]
public bool CheckBoxes
{
get
{
return mCheckBoxes;
}
set
{
mCheckBoxes = value;
}
}
[System.ComponentModel.Description("Use this property to set item separator1 character."), System.ComponentModel.Category("Power Properties")]
public char ItemSeparator1
{
get
{
return mItemSeparator1;
}
set
{
mItemSeparator1 = value;
}
}
[System.ComponentModel.Description("Use this property to set item separator2 character."), System.ComponentModel.Category("Power Properties")]
public char ItemSeparator2
{
get
{
return mItemSeparator2;
}
set
{
mItemSeparator2 = value;
}
}
//overrides
protected override void OnTextChanged(System.EventArgs e)
{
base.OnTextChanged(e);
}
protected override void OnSelectedIndexChanged(System.EventArgs e)
{
//cancels SIC when user try to select a group
if (this.DividerFormat.Length > 0 && this.Text.Contains(this.mDividerFormat))
{
this.SelectedIndex = mLastSelectedIndex; //NOTE restorre last valid selection
return;
}
mLastSelectedIndex = this.SelectedIndex;
base.OnSelectedIndexChanged(e);
}
protected override void OnDrawItem(DrawItemEventArgs e)
{
Int32 zX1 = 0;
Pen zPen = null;
float zWidth = 0F;
string zText = null;
Font zFont = null;
Color zFore = new Color();
System.Windows.Forms.VisualStyles.CheckBoxState zState = 0;
if (e.Index < 0)
{
base.OnDrawItem(e);
return; //fix for designer error - hope doesnt effect runtime drawing
}
//NOTE 1st part of if statement draw group item, 2nd draws actual item
if (this.Items[e.Index].ToString().Contains(this.mDividerFormat) & mDividerFormat.Length > 0)
{
//background
if (e.Index == SelectedIndex)
{
e.DrawBackground();
}
zText = this.Items[e.Index].ToString();
zText = " " zText.Replace(this.mDividerFormat, "") " ";
zFont = new Font(Font, FontStyle.Bold); //group item
if (e.BackColor == System.Drawing.SystemColors.Highlight)
{
zFore = Color.Gainsboro; //Color.LightGray 'Color.Silver 'gray colr lets user know that shouldn't be selecting a group item
}
else
{
zFore = this.GroupColor; //e.ForeColor
}
zPen = new Pen(zFore);
//draw group
zWidth = e.Graphics.MeasureString(zText, zFont).Width;
zX1 = Convert.ToInt32(e.Bounds.Width - zWidth) / 2;
e.Graphics.DrawRectangle(zPen, new Rectangle(e.Bounds.X, e.Bounds.Y e.Bounds.Height / 2, zX1, 1));
e.Graphics.DrawRectangle(zPen, new Rectangle(e.Bounds.Width - zX1, e.Bounds.Y e.Bounds.Height / 2, e.Bounds.Width, 1));
e.Graphics.DrawString(zText, zFont, new SolidBrush(zFore), zX1, e.Bounds.Top);
}
else
{
if (mRedrawingUnselected)
{
if (mIndex % 2 == 0)
{
e.Graphics.FillRectangle(new SolidBrush(Color.White), mBounds); //e.Bounds)'FIX for wrong bound being passed
}
else
{
e.Graphics.FillRectangle(new SolidBrush(mGridColor), mBounds); //e.Bounds) 'FIX for wrong bound being passed
}
}
else
{
if (e.Index == SelectedIndex)
{
e.DrawBackground();
}
else
{
if (e.Index % 2 == 0)
{
e.Graphics.FillRectangle(new SolidBrush(Color.White), e.Bounds);
}
else
{
e.Graphics.FillRectangle(new SolidBrush(mGridColor), e.Bounds);
}
}
}
//checkbox work
if (mCheckBoxes)
{
if (e.BackColor == System.Drawing.SystemColors.Highlight)
{
if (this.GetItemsChecks(e.Index))
{
zState = System.Windows.Forms.VisualStyles.CheckBoxState.CheckedHot;
}
else
{
zState = System.Windows.Forms.VisualStyles.CheckBoxState.UncheckedHot;
}
}
else
{
if (this.GetItemsChecks(e.Index))
{
zState = System.Windows.Forms.VisualStyles.CheckBoxState.CheckedNormal;
}
else
{
zState = System.Windows.Forms.VisualStyles.CheckBoxState.UncheckedNormal;
}
}
zX1 = this.FontHeight; /// 2 'variable re-use
zPen = new Pen(Color.Black, 1F);
zPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot;
//e.Graphics.DrawLine(zPen, e.Bounds.Left, e.Bounds.Top zX1, e.Bounds.Left e.Bounds.Width, e.Bounds.Top zX1)
System.Windows.Forms.CheckBoxRenderer.DrawCheckBox(e.Graphics, new System.Drawing.Point(e.Bounds.X e.Bounds.Width - 15, e.Bounds.Y 1), e.Bounds, "", this.Font, false, zState);
}
//text work
e.Graphics.DrawString(this.Items[e.Index].ToString(), Font, new SolidBrush(e.ForeColor), e.Bounds.Left, e.Bounds.Top);
}
//exits here when redrawing unselected
if (mRedrawingUnselected)
{
mRedrawingUnselected = false;
}
else
{
//NOTE just seems to work 100% when timer is used in conjunction with .Bound override of old graphics property
if (SelectedIndex == e.Index)
{
mGraphics_t = e.Graphics;
mBounds_t = e.Bounds;
mIndex_t = e.Index;
mTimer1 = new Timer();
mTimer1.Interval = 5;
mTimer1.Enabled = true;
mTimer1.Tick = new EventHandler(mTimer1_Tick);
}
}
base.OnDrawItem(e);
}
protected override void WndProc(ref System.Windows.Forms.Message m)
{
const Int32 WM_SETCURSOR = 32;
const Int32 WM_WINDOWPOSCHANGING = 70;
const Int32 WM_COMMAND = 273;
const int WM_CTLCOLORLISTBOX = 308;
const Int32 CB_ADDSTRING = 323;
const Int32 CB_GETCURSEL = 327;
const Int32 WM_LBUTTONUP = 514;
const Int32 OCM_COMMAND = 8465;
Int32 yPos = 0;
//INSTANT C# NOTE: The following VB 'Select Case' included range-type or non-constant 'Case' expressions and was converted to C# 'if-else' logic:
// Select Case true
//ORIGINAL LINE: Case m.Msg = WM_WINDOWPOSCHANGING //.DropDownClose (more effective catching of )
if (true == (m.Msg == WM_WINDOWPOSCHANGING)) //.DropDownClose (more effective catching of )
{
}
//ORIGINAL LINE: Case m.Msg = WM_CTLCOLORLISTBOX Or m.Msg = WM_SETCURSOR //.ItemHover (more effective catching of )
else if (true == (m.Msg == WM_CTLCOLORLISTBOX | m.Msg == WM_SETCURSOR)) //.ItemHover (more effective catching of )
{
yPos = this.PointToClient(System.Windows.Forms.Cursor.Position).Y;
if (this.DropDownStyle == ComboBoxStyle.Simple)
{
yPos -= (this.ItemHeight 10);
}
else
{
yPos -= (this.Size.Height 1);
}
mHoverIndex = yPos / this.ItemHeight;
if (mHoverIndex >= 0) //FIX for not raising event on mouse over text
{
mHoverIndex = Convert.ToInt32(mHoverIndex);
if (mHoverIndex > -1 & mHoverIndex < this.Items.Count & this.DroppedDown)
{
if (ItemHover != null)
ItemHover(Convert.ToInt32(mHoverIndex));
}
}
else
{
//NOTE should really raisevent with -1
}
}
//ORIGINAL LINE: Case m.Msg = CB_ADDSTRING And m.WParam = new IntPtr(0) //.AddItem(s) for stretching ItemChecks array
else if (true == (m.Msg == CB_ADDSTRING & m.WParam == new IntPtr(0))) //.AddItem(s) for stretching ItemChecks array
{
StretchCheckList();
}
//ORIGINAL LINE: Case m.Msg = WM_COMMAND And m.WParam = new System.IntPtr(66536) //intercepts WM_COMMAND (which prevent DropDownBox from closing after WM_LBUTTONDOWN)
else if (true == (m.Msg == WM_COMMAND & m.WParam == new System.IntPtr(66536))) //intercepts WM_COMMAND (which prevent DropDownBox from closing after WM_LBUTTONDOWN)
{
//.(.ToString)
//0. normal behaviour when no checkboxes
if (! this.mCheckBoxes)
{
base.WndProc(ref m);
return;
}
//cancels SIC when user try to select a group
if (this.DividerFormat.Length > 0 && Convert.ToString(this.Items[Convert.ToInt32(mHoverIndex)]).Contains(this.mDividerFormat))
{
//Me.SelectedIndex = mLastSelectedIndex 'NOTE restorre last valid selection
//Exit Sub
base.WndProc(ref m);
return;
}
//1. reconstructs (cancelled) child events from WM_COMMAND MSG
PowerComboBox.SendMessage(this.Handle, OCM_COMMAND, 591814, new IntPtr(1705748)); //1 event reconstruuction
PowerComboBox.SendMessage(this.Handle, OCM_COMMAND, 67526, new IntPtr(1705748)); //2 flagging redraw
PowerComboBox.SendMessage(this.Handle, CB_GETCURSEL, 0, new IntPtr(0)); //3 event reconstruuction
PowerComboBox.SendMessage(this.Handle, WM_LBUTTONUP, 0, new IntPtr(721012)); //4 flagging redraw
//2. toggle checkbox
if (SelectedIndex > -1)
{
this.SetItemsChecks(SelectedIndex, ! (this.GetItemsChecks(SelectedIndex)));
}
// Me.ItemsChecks(mHoverIndex) = Not Me.ItemsChecks(mHoverIndex)
//3. throw 'hover' \ Msg308 Or Msg32 so item is repainted
if (this.SelectedIndex == 0)
{
yPos = this.Font.Height;
}
else
{
yPos = this.Font.Height * -1;
}
System.Windows.Forms.Cursor.Position = new Point(System.Windows.Forms.Cursor.Position.X, System.Windows.Forms.Cursor.Position.Y yPos);
Application.DoEvents();
System.Windows.Forms.Cursor.Position = new Point(System.Windows.Forms.Cursor.Position.X, System.Windows.Forms.Cursor.Position.Y - yPos);
this.Text = GetCommaText(); //NEW CSV test for checkboxes
//4. cancels event
return;
}
base.WndProc(ref m);
}
//private
private void StretchCheckList()
{
Array.Resize(ref mItemsChecks, this.Items.Count);
}
private void mTimer1_Tick(object sender, System.EventArgs e)
{
mTimer1.Enabled = false;
mRedrawingUnselected = true;
base.OnDrawItem(new System.Windows.Forms.DrawItemEventArgs(mGraphics, this.Font, mBounds, mIndex, DrawItemState.Default));
mGraphics = mGraphics_t;
mBounds = mBounds_t;
mIndex = mIndex_t;
}
private string GetCommaText()
{
Int32 i = 0;
System.Text.StringBuilder sb = new System.Text.StringBuilder("");
string s = null;
string zFirst = null;
string zLast = null;
Int32 zLastComa = 0;
string zconverterror=null;
if (! this.CheckBoxes)
{
return this.Text;
}
for (i = 0; i < this.Items.Count; i )
{
if (this.GetItemsChecks(i) == true)
{
sb.Append(this.Items[i]);
sb.Append(mItemSeparator1);
}
}
s = sb.ToString();
if (s.Length == 0)
{
return this.Text;
}
s = s.Substring(0, s.Length - 1);
zLastComa = s.LastIndexOf(mItemSeparator1);
if (zLastComa == -1)
{
return this.Text;
}
zLast = s.Substring(zLastComa);
zFirst = s.Substring(0, zLastComa);
zconverterror = Convert.ToString(mItemSeparator2);
zconverterror = Convert.ToString(" ");
s = zFirst Convert.ToString(" ");
s = zLast.Replace(Convert.ToString(mItemSeparator1), zconverterror);
return s;
}
}
}
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