Beispiel eines Windows Forms-Steuerelements
Anhand dieses Beispiels wird ein benutzerdefiniertes Steuerelement (FlashTrackBar) beschrieben, das zum Anzeigen der Ebene oder des Fortschritts einer Anwendung verwendet werden kann. Der Fortschritt wird mit Hilfe eines Farbverlaufs visuell dargestellt. Den Quellcode für FlashTrackBar und ein Verwendungsbeispiel finden Sie im CustomUITypeEditor-Beispiel in .NET-Beispiele - Windows Forms: Erstellen von Steuerelementen. In diesem Thema werden Editoren beschrieben, die mit dem zugrunde liegenden FlashTrackBar-Beispiel verwendet werden.
Das FlashTrackBar-Steuerelement veranschaulicht folgende Konzepte:
- Das Definieren benutzerdefinierter Eigenschaften.
- Das Definieren benutzerdefinierter Ereignisse. (
FlashTrackBardefiniert dasValueChanged-Ereignis.) - Das Außerkraftsetzen der OnPaint-Methode, um Logik zum Zeichnen des Steuerelements bereitzustellen.
- Das Berechnen des Bereichs, der zum Zeichnen des Steuerelements zur Verfügung steht, indem die ClientRectangle-Eigenschaft verwendet wird.
FlashTrackBarführt dies in der dazugehörigenOptimizedInvalidate-Methode aus. - Implementieren der Serialisierung (Dauerhaftigkeit) für eine Eigenschaft, wenn sie im Designer geändert wird.
FlashTrackBardefiniert dieShouldSerializeStartColor-Methode und dieShouldSerializeEndColor-Methode für die Serialisierung der dazugehörigenStartColor-Eigenschaft und der dazugehörigenEndColor-Eigenschaft.
FlashTrackBar definiert die folgenden benutzerdefinierten Eigenschaften:
AllowUserEditZeigt an, ob der Benutzer den Wert der Flashtrackleiste ändern kann, indem er darauf klickt und zieht.
EndColorGibt die Farbe am Ende der Trackleiste an.
DarkenByGibt an, wie stark der Hintergrund im Vergleich zum Farbverlauf des Vordergrunds abgedunkelt werden muss.
MaxGibt den höchsten Wert der Trackleiste an.
MinGibt den niedrigsten Wert der Trackleiste an.
StartColorGibt die Anfangsfarbe des Farbverlaufs an.
ShowPercentageGibt an, ob über dem Farbverlauf eine Prozentangabe angezeigt wird.
ShowValueGibt an, ob über dem Farbverlauf der aktuelle Wert angezeigt wird.
ShowGradientGibt an, ob in der Trackleiste ein Farbverlauf für den aktuellen Wert angezeigt wird.
ValueGibt den aktuellen Wert der Trackleiste an.
FlashTrackBar definiert das folgende anhand einer Eigenschaft geänderte Ereignis sowie die Methode, die das Ereignis auslöst:
ValueChangedDas Ereignis, das ausgelöst wird, wenn sich die
Value-Eigenschaft der Trackleiste ändert.OnValueChangedDie Methode, die das
ValueChanged-Ereignis auslöst.Hinweis
FlashTrackBarverwendet die EventArgs-Klasse für Ereignisdaten und EventHandler für den Ereignisdelegaten.
FlashTrackBar setzt die folgenden von System.Windows.Forms.Control geerbten Methoden außer Kraft, um die entsprechenden EventName-Ereignisse zu behandeln:
FlashTrackBar setzt die folgenden von System.Windows.Forms.Control geerbten Methoden außer Kraft, um die entsprechenden, anhand von Eigenschaften geänderten Ereignisse zu behandeln:
-
**Hinweis **Sie müssen dieses Beispiel zusammen mit den Typ-Editoren für die Benutzeroberfläche für dieses Steuerelement (
FlashTrackBarUITypeEditorundFlashTrackBarDarkenByEditor) kompilieren (siehe Beispiel für einen Typ-Editor für die Benutzeroberfläche in Windows Forms). Anweisungen zum Erstellen dieses Beispiels finden Sie im CustomUITypeEditor-Beispiel in .NET-Beispiele - Windows Forms: Erstellen von Steuerelementen.
Imports System
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Drawing.Design
Imports System.Windows.Forms
Imports System.Diagnostics
Namespace Microsoft.Samples.WinForms.VB.FlashTrackBar
Public Class FlashTrackBar
Inherits System.Windows.Forms.Control
Private LeftRightBorder As Integer = 10
Private myValue As Integer = 0
Private myMin As Integer = 0
Private myMax As Integer = 100
Private myShowPercentage As Boolean = False
Private myShowValue As Boolean = False
Private myAllowUserEdit As Boolean = True
Private myShowGradient As Boolean = True
Private dragValue As Integer = 0
Private dragging As Boolean = False
Private myStartColor As Color = Color.Red
Private myEndColor As Color = Color.LimeGreen
Private baseBackground As Brush
Private backgroundDim As Brush
Private myDarkenBy As Byte = 200
Public Sub New()
MyBase.New()
' This call is required by the Windows Forms Designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
SetStyle(ControlStyles.Opaque, True)
SetStyle(ControlStyles.ResizeRedraw, True)
Debug.Assert(GetStyle(ControlStyles.ResizeRedraw), "Should be redraw!")
End Sub
' Form overrides Dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(disposing As Boolean)
If disposing
If Not components Is Nothing
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub
#Region " Windows Forms Designer generated code "
' Required by the Windows Forms Designer.
Private components As System.ComponentModel.Container
' Note: The following procedure is required by the Windows Forms Designer.
' It can be modified using the Windows Forms Designer.
' Do not modify it using the code editor.
Private Sub InitializeComponent()
Me.components = New System.ComponentModel.Container()
Me.ForeColor = System.Drawing.Color.White
Me.BackColor = System.Drawing.Color.Black
Me.Size = New System.Drawing.Size(100, 23)
Me.Text = "FlashTrackBar"
End Sub
#End Region
<Category("Flash"), DefaultValue(True)> Public Property AllowUserEdit() As Boolean
Get
Return myAllowUserEdit
End Get
Set(ByVal Value As Boolean)
If (Value <> myAllowUserEdit) Then
myAllowUserEdit = Value
If Not (myAllowUserEdit) Then
Capture = False
dragging = False
End If
End If
End Set
End Property
<Category("Flash")> Public Property EndColor() As Color
Get
Return myEndColor
End Get
Set(ByVal Value As Color)
myEndColor = Value
If (Not (baseBackground Is Nothing) And myShowGradient) Then
baseBackground.Dispose()
baseBackground = Nothing
End If
Invalidate()
End Set
End Property
Public Function ShouldSerializeEndColor() As Boolean
Return Not (myEndColor.Equals(Color.LimeGreen))
End Function
<Category("Flash"), _
Editor(GetType(FlashTrackBarDarkenByEditor), GetType(UITypeEditor)), _
DefaultValue(200)> _
Public Property DarkenBy() As Byte
Get
Return myDarkenBy
End Get
Set(ByVal Value As Byte)
If (Value <> myDarkenBy) Then
myDarkenBy = Value
If Not (backgroundDim Is Nothing) Then
backgroundDim.Dispose()
backgroundDim = Nothing
End If
OptimizedInvalidate(Value, Max)
End If
End Set
End Property
<Category("Flash"), DefaultValue(100)> _
Public Property Max() As Integer
Get
Return myMax
End Get
Set(ByVal Value As Integer)
If (myMax <> Value) Then
myMax = Value
Invalidate()
End If
End Set
End Property
<Category("Flash"), DefaultValue(0)> _
Public Property Min() As Integer
Get
Return myMin
End Get
Set(ByVal Value As Integer)
If (Min <> Value) Then
Min = Value
Invalidate()
End If
End Set
End Property
<Category("Flash")> Public Property StartColor() As Color
Get
Return myStartColor
End Get
Set(ByVal Value As Color)
myStartColor = Value
If (Not (baseBackground Is Nothing) And myShowGradient) Then
baseBackground.Dispose()
baseBackground = Nothing
End If
Invalidate()
End Set
End Property
Public Function ShouldSerializeStartColor() As Boolean
Return Not (StartColor.Equals(Color.Red))
End Function
<Category("Flash"), _
RefreshProperties(RefreshProperties.Repaint), _
DefaultValue(False)> _
Public Property ShowPercentage() As Boolean
Get
Return myShowPercentage
End Get
Set(ByVal Value As Boolean)
If (Value <> myShowPercentage) Then
myShowPercentage = Value
If (myShowPercentage) Then
myShowValue = False
End If
Invalidate()
End If
End Set
End Property
<Category("Flash"), _
RefreshProperties(RefreshProperties.Repaint), _
DefaultValue(False)> _
Public Property ShowValue() As Boolean
Get
Return myShowValue
End Get
Set(ByVal Value As Boolean)
If (Value <> myShowValue) Then
myShowValue = Value
If (myShowValue) Then
myShowPercentage = False
End If
Invalidate()
End If
End Set
End Property
<Category("Flash"), DefaultValue(True)> _
Public Property ShowGradient() As Boolean
Get
Return myShowGradient
End Get
Set(ByVal Value As Boolean)
If (Value <> myShowGradient) Then
myShowGradient = Value
If Not (baseBackground Is Nothing) Then
baseBackground.Dispose()
baseBackground = Nothing
End If
Invalidate()
End If
End Set
End Property
<Category("Flash"), _
Editor(GetType(FlashTrackBarValueEditor), GetType(UITypeEditor)), _
DefaultValue(0)> _
Public Property Value() As Integer
Get
If (dragging) Then
Return dragValue
End If
Return myValue
End Get
Set(ByVal Value As Integer)
If (Value <> myValue) Then
Dim old As Integer = myValue
myValue = Value
OnValueChanged(EventArgs.Empty)
OptimizedInvalidate(old, myValue)
End If
End Set
End Property
' ValueChanged event.
<Description("Raised when the Value displayed changes")> _
Public Event ValueChanged(ByVal sender As Object, ByVal ev As EventArgs)
' As EventHandler.
Private Sub OptimizedInvalidate(ByVal oldValue As Integer, ByVal newValue As Integer)
Dim client As Rectangle = ClientRectangle
Dim oldPercentValue As Single = CSng(oldValue) / (CSng(Max) - CSng(Min))
Dim oldNonDimLength As Integer = CInt(oldPercentValue * CSng(client.Width))
Dim newPercentValue As Single = (CSng(newValue) / (CSng(Max) - CSng(Min)))
Dim newNonDimLength As Integer = CInt(newPercentValue * CSng(client.Width))
Dim lmin As Integer = Math.Min(oldNonDimLength, newNonDimLength)
Dim lmax As Integer = Math.Max(oldNonDimLength, newNonDimLength)
Dim invalid As Rectangle = New Rectangle(client.X + lmin, client.Y, lmax - lmin, client.Height)
Invalidate(invalid)
Dim oldToDisplay As String
Dim newToDisplay As String
If (ShowPercentage) Then
oldToDisplay = Convert.ToString(CInt(oldPercentValue * 100F)) + "%"
newToDisplay = Convert.ToString(CInt(newPercentValue * 100F)) + "%"
ElseIf (ShowValue) Then
oldToDisplay = Convert.ToString(oldValue)
newToDisplay = Convert.ToString(newValue)
Else
oldToDisplay = Nothing
newToDisplay = Nothing
End If
If (oldToDisplay <> Nothing And newToDisplay <> Nothing) Then
Dim g As Graphics = CreateGraphics()
Dim oldFontSize As SizeF = g.MeasureString(oldToDisplay, Font)
Dim newFontSize As SizeF = g.MeasureString(newToDisplay, Font)
Dim oldFontRectF As RectangleF = New RectangleF(New PointF(0, 0), oldFontSize)
Dim newFontRectF As RectangleF = New RectangleF(New PointF(0, 0), newFontSize)
oldFontRectF.X = (client.Width - oldFontRectF.Width) / 2
oldFontRectF.Y = (client.Height - oldFontRectF.Height) / 2
newFontRectF.X = (client.Width - newFontRectF.Width) / 2
newFontRectF.Y = (client.Height - newFontRectF.Height) / 2
Dim oldFontRect As Rectangle = New Rectangle(CInt(oldFontRectF.X), CInt(oldFontRectF.Y), CInt(oldFontRectF.Width), CInt(oldFontRectF.Height))
Dim newFontRect As Rectangle = New Rectangle(CInt(newFontRectF.X), CInt(newFontRectF.Y), CInt(newFontRectF.Width), CInt(newFontRectF.Height))
Invalidate(oldFontRect)
Invalidate(newFontRect)
End If
End Sub
Protected Overrides Sub OnMouseDown(ByVal e As MouseEventArgs)
MyBase.OnMouseDown(e)
If Not (myAllowUserEdit) Then
Return
End If
Capture = True
dragging = True
SetDragValue(New Point(e.X, e.Y))
End Sub
Protected Overrides Sub OnMouseMove(ByVal e As MouseEventArgs)
MyBase.OnMouseMove(e)
If (Not myAllowUserEdit Or Not dragging) Then
Return
End If
SetDragValue(New Point(e.X, e.Y))
End Sub
Protected Overrides Sub OnMouseUp(ByVal e As MouseEventArgs)
MyBase.OnMouseUp(e)
If (Not myAllowUserEdit Or Not dragging) Then
Return
End If
Capture = False
dragging = False
Value = dragValue
OnValueChanged(EventArgs.Empty)
End Sub
Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
MyBase.OnPaint(e)
If (baseBackground Is Nothing) Then
If (myShowGradient) Then
baseBackground = New LinearGradientBrush(New Point(0, 0), _
New Point(ClientSize.Width, 0), _
StartColor, _
EndColor)
ElseIf Not (BackgroundImage Is Nothing) Then
baseBackground = New TextureBrush(BackgroundImage)
Else
baseBackground = New SolidBrush(BackColor)
End If
End If
If (backgroundDim Is Nothing) Then
backgroundDim = New SolidBrush(Color.FromArgb(DarkenBy, Color.Black))
End If
Dim toDim As Rectangle = ClientRectangle
Dim percentValue As Single = (CSng(Value) / (CSng(Max) - CSng(Min)))
Dim nonDimLength As Integer = CInt(percentValue * CSng(toDim.Width))
toDim.X = toDim.X + nonDimLength
toDim.Width = toDim.Width - nonDimLength
Dim ltext As String = Me.Text
Dim toDisplay As String
Dim textRect As RectangleF = New RectangleF(0, 0, 0, 0)
If (ShowPercentage Or ShowValue Or ltext.Length > 0) Then
If (ShowPercentage) Then
toDisplay = Convert.ToString(CInt(percentValue * 100F)) + "%"
ElseIf (ShowValue) Then
toDisplay = Convert.ToString(Value)
Else
toDisplay = ltext
End If
Dim textSize As SizeF = e.Graphics.MeasureString(toDisplay, Font)
textRect.Width = textSize.Width
textRect.Height = textSize.Height
textRect.X = (ClientRectangle.Width - textRect.Width) / 2
textRect.Y = (ClientRectangle.Height - textRect.Height) / 2
End If
e.Graphics.FillRectangle(baseBackground, ClientRectangle)
e.Graphics.FillRectangle(backgroundDim, toDim)
e.Graphics.Flush()
If (toDisplay <> Nothing And toDisplay.Length > 0) Then
e.Graphics.DrawString(toDisplay, Font, New SolidBrush(ForeColor), textRect)
End If
End Sub
Protected Overrides Sub OnTextChanged(ByVal E As EventArgs)
MyBase.OnTextChanged(E)
Invalidate()
End Sub
Protected Overrides Sub OnBackColorChanged(ByVal E As EventArgs)
MyBase.OnTextChanged(E)
If Not (baseBackground Is Nothing) And Not ShowGradient Then
baseBackground.Dispose()
baseBackground = Nothing
End If
End Sub
Protected Overrides Sub OnBackgroundImageChanged(ByVal E As EventArgs)
MyBase.OnTextChanged(E)
If Not (baseBackground Is Nothing) And Not ShowGradient Then
baseBackground.Dispose()
baseBackground = Nothing
End If
End Sub
Protected Overrides Sub OnResize(ByVal e As EventArgs)
MyBase.OnResize(e)
If Not (baseBackground Is Nothing) Then
baseBackground.Dispose()
baseBackground = Nothing
End If
End Sub
Protected Overridable Sub OnValueChanged(ByVal e As EventArgs)
RaiseEvent ValueChanged(Me, e)
End Sub
Private Sub SetDragValue(ByVal mouseLocation As Point)
Dim client As Rectangle = ClientRectangle
If (client.Contains(mouseLocation)) Then
Dim percentage As Single = CSng(mouseLocation.X) / CSng(ClientRectangle.Width)
Dim newDragValue As Integer = CInt(percentage * CSng(Max - Min))
If (newDragValue <> dragValue) Then
Dim old As Integer = dragValue
dragValue = newDragValue
OptimizedInvalidate(old, dragValue)
End If
Else
If (client.Y <= mouseLocation.Y And mouseLocation.Y <= client.Y + client.Height) Then
If (mouseLocation.X <= client.X And mouseLocation.X > client.X - LeftRightBorder) Then
Dim newDragValue As Integer = Min
If (newDragValue <> dragValue) Then
Dim old As Integer = dragValue
dragValue = newDragValue
OptimizedInvalidate(old, dragValue)
End If
ElseIf (mouseLocation.X >= client.X + client.Width And mouseLocation.X < client.X + client.Width + LeftRightBorder) Then
Dim newDragValue As Integer = Max
If (newDragValue <> dragValue) Then
Dim old As Integer = dragValue
dragValue = newDragValue
OptimizedInvalidate(old, dragValue)
End If
End If
Else
If (dragValue <> Value) Then
Dim old As Integer = dragValue
dragValue = Value
OptimizedInvalidate(old, dragValue)
End If
End If
End If
End Sub
End Class
End Namespace
[C#]
namespace Microsoft.Samples.WinForms.Cs.FlashTrackBar {
using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Design;
using System.Windows.Forms;
using System.Diagnostics;
public class FlashTrackBar : System.Windows.Forms.Control {
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components;
private const int LeftRightBorder = 10;
private int value = 0;
private int min = 0;
private int max = 100;
private bool showPercentage = false;
private bool showValue = false;
private bool allowUserEdit = true;
private bool showGradient = true;
private int dragValue = 0;
private bool dragging = false;
private Color startColor = Color.Red;
private Color endColor = Color.LimeGreen;
private EventHandler onValueChanged;
private Brush baseBackground = null;
private Brush backgroundDim = null;
private byte darkenBy = 200;
public FlashTrackBar() {
//
// Required for Windows Form designer support.
//
InitializeComponent();
//
// Add any constructor code after the InitializeComponent call.
//
SetStyle(ControlStyles.Opaque, true);
SetStyle(ControlStyles.ResizeRedraw, true);
Debug.Assert(GetStyle(ControlStyles.ResizeRedraw), "Should be redraw!");
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose(bool disposing) {
if (disposing) {
if (components != null) {
components.Dispose();
}
}
base.Dispose(disposing);
}
/// <summary>
/// Required method for designer support. Do not modify
/// the contents of this method with the code editor.
/// </summary>
void InitializeComponent () {
this.components = new System.ComponentModel.Container ();
this.ForeColor = System.Drawing.Color.White;
this.BackColor = System.Drawing.Color.Black;
this.Size = new System.Drawing.Size(100, 23);
this.Text = "FlashTrackBar";
}
[
Category("Flash"),
DefaultValue(true)
]
public bool AllowUserEdit {
get {
return allowUserEdit;
}
set {
if (value != allowUserEdit) {
allowUserEdit = value;
if (!allowUserEdit) {
Capture = false;
dragging = false;
}
}
}
}
[
Category("Flash")
]
public Color EndColor {
get {
return endColor;
}
set {
endColor = value;
if (baseBackground != null && showGradient) {
baseBackground.Dispose();
baseBackground = null;
}
Invalidate();
}
}
public bool ShouldSerializeEndColor() {
return !(endColor == Color.LimeGreen);
}
[
Category("Flash"),
Editor(typeof(FlashTrackBarDarkenByEditor), typeof(UITypeEditor)),
DefaultValue((byte)200)
]
public byte DarkenBy {
get {
return darkenBy;
}
set {
if (value != darkenBy) {
darkenBy = value;
if (backgroundDim != null) {
backgroundDim.Dispose();
backgroundDim = null;
}
OptimizedInvalidate(Value, max);
}
}
}
[
Category("Flash"),
DefaultValue(100)
]
public int Max {
get {
return max;
}
set {
if (max != value) {
max = value;
Invalidate();
}
}
}
[
Category("Flash"),
DefaultValue(0)
]
public int Min {
get {
return min;
}
set {
if (min != value) {
min = value;
Invalidate();
}
}
}
[
Category("Flash")
]
public Color StartColor {
get {
return startColor;
}
set {
startColor = value;
if (baseBackground != null && showGradient) {
baseBackground.Dispose();
baseBackground = null;
}
Invalidate();
}
}
public bool ShouldSerializeStartColor() {
return !(startColor == Color.Red);
}
[
Category("Flash"),
RefreshProperties(RefreshProperties.Repaint),
DefaultValue(false)
]
public bool ShowPercentage {
get {
return showPercentage;
}
set {
if (value != showPercentage) {
showPercentage = value;
if (showPercentage) {
showValue = false;
}
Invalidate();
}
}
}
[
Category("Flash"),
RefreshProperties(RefreshProperties.Repaint),
DefaultValue(false)
]
public bool ShowValue {
get {
return showValue;
}
set {
if (value != showValue) {
showValue = value;
if (showValue) {
showPercentage = false;
}
Invalidate();
}
}
}
[
Category("Flash"),
DefaultValue(true)
]
public bool ShowGradient {
get {
return showGradient;
}
set {
if (value != showGradient) {
showGradient = value;
if (baseBackground != null) {
baseBackground.Dispose();
baseBackground = null;
}
Invalidate();
}
}
}
[
Category("Flash"),
Editor(typeof(FlashTrackBarValueEditor), typeof(UITypeEditor)),
DefaultValue(0)
]
public int Value {
get {
if (dragging) {
return dragValue;
}
return value;
}
set {
if (value != this.value) {
int old = this.value;
this.value = value;
OnValueChanged(EventArgs.Empty);
OptimizedInvalidate(old, this.value);
}
}
}
// ValueChanged Event.
[Description("Raised when the Value displayed changes")]
public event EventHandler ValueChanged {
add {
onValueChanged += value;
}
remove {
onValueChanged -= value;
}
}
private void OptimizedInvalidate(int oldValue, int newValue) {
Rectangle client = ClientRectangle;
float oldPercentValue = ((float)oldValue / ((float)Max - (float)Min));
int oldNonDimLength = (int)(oldPercentValue * (float)client.Width);
float newPercentValue = ((float)newValue / ((float)Max - (float)Min));
int newNonDimLength = (int)(newPercentValue * (float)client.Width);
int min = Math.Min(oldNonDimLength, newNonDimLength);
int max = Math.Max(oldNonDimLength, newNonDimLength);
Rectangle invalid = new Rectangle(client.X + min, client.Y, max - min, client.Height);
Invalidate(invalid);
string oldToDisplay;
string newToDisplay;
if (ShowPercentage) {
oldToDisplay = Convert.ToString((int)(oldPercentValue * 100f)) + "%";
newToDisplay = Convert.ToString((int)(newPercentValue * 100f)) + "%";
}
else if (ShowValue) {
oldToDisplay = Convert.ToString(oldValue);
newToDisplay = Convert.ToString(newValue);
}
else {
oldToDisplay = null;
newToDisplay = null;
}
if (oldToDisplay != null && newToDisplay != null) {
Graphics g = CreateGraphics();
SizeF oldFontSize = g.MeasureString(oldToDisplay, Font);
SizeF newFontSize = g.MeasureString(newToDisplay, Font);
RectangleF oldFontRect = new RectangleF(new PointF(0, 0), oldFontSize);
RectangleF newFontRect = new RectangleF(new PointF(0, 0), newFontSize);
oldFontRect.X = (client.Width - oldFontRect.Width) / 2;
oldFontRect.Y = (client.Height - oldFontRect.Height) / 2;
newFontRect.X = (client.Width - newFontRect.Width) / 2;
newFontRect.Y = (client.Height - newFontRect.Height) / 2;
Invalidate(new Rectangle((int)oldFontRect.X, (int)oldFontRect.Y, (int)oldFontRect.Width, (int)oldFontRect.Height));
Invalidate(new Rectangle((int)newFontRect.X, (int)newFontRect.Y, (int)newFontRect.Width, (int)newFontRect.Height));
}
}
protected override void OnMouseDown(MouseEventArgs e) {
base.OnMouseDown(e);
if (!allowUserEdit) {
return;
}
Capture = true;
dragging = true;
SetDragValue(new Point(e.X, e.Y));
}
protected override void OnMouseMove(MouseEventArgs e) {
base.OnMouseMove(e);
if (!allowUserEdit || !dragging) {
return;
}
SetDragValue(new Point(e.X, e.Y));
}
protected override void OnMouseUp(MouseEventArgs e) {
base.OnMouseUp(e);
if (!allowUserEdit || !dragging) {
return;
}
Capture = false;
dragging = false;
value = dragValue;
OnValueChanged(EventArgs.Empty);
}
protected override void OnPaint(PaintEventArgs e) {
base.OnPaint(e);
if (baseBackground == null) {
if (showGradient) {
baseBackground = new LinearGradientBrush(new Point(0, 0),
new Point(ClientSize.Width, 0),
StartColor,
EndColor);
}
else if (BackgroundImage != null) {
baseBackground = new TextureBrush(BackgroundImage);
}
else {
baseBackground = new SolidBrush(BackColor);
}
}
if (backgroundDim == null) {
backgroundDim = new SolidBrush(Color.FromArgb(DarkenBy, Color.Black));
}
Rectangle toDim = ClientRectangle;
float percentValue = ((float)Value / ((float)Max - (float)Min));
int nonDimLength = (int)(percentValue * (float)toDim.Width);
toDim.X += nonDimLength;
toDim.Width -= nonDimLength;
string text = Text;
string toDisplay = null;
RectangleF textRect = new RectangleF();
if (ShowPercentage || ShowValue || text.Length > 0) {
if (ShowPercentage) {
toDisplay = Convert.ToString((int)(percentValue * 100f)) + "%";
}
else if (ShowValue) {
toDisplay = Convert.ToString(Value);
}
else {
toDisplay = text;
}
SizeF textSize = e.Graphics.MeasureString(toDisplay, Font);
textRect.Width = textSize.Width;
textRect.Height = textSize.Height;
textRect.X = (ClientRectangle.Width - textRect.Width) / 2;
textRect.Y = (ClientRectangle.Height - textRect.Height) / 2;
}
e.Graphics.FillRectangle(baseBackground, ClientRectangle);
e.Graphics.FillRectangle(backgroundDim, toDim);
e.Graphics.Flush();
if (toDisplay != null && toDisplay.Length > 0) {
e.Graphics.DrawString(toDisplay, Font, new SolidBrush(ForeColor), textRect);
}
}
protected override void OnTextChanged(EventArgs e) {
base.OnTextChanged(e);
Invalidate();
}
protected override void OnBackColorChanged(EventArgs e) {
base.OnTextChanged(e);
if ((baseBackground != null) && (!showGradient)) {
baseBackground.Dispose();
baseBackground = null;
}
}
protected override void OnBackgroundImageChanged(EventArgs e) {
base.OnTextChanged(e);
if ((baseBackground != null) && (!showGradient)) {
baseBackground.Dispose();
baseBackground = null;
}
}
protected override void OnResize(EventArgs e) {
base.OnResize(e);
if (baseBackground != null) {
baseBackground.Dispose();
baseBackground = null;
}
}
protected virtual void OnValueChanged(EventArgs e) {
if (onValueChanged != null) {
onValueChanged.Invoke(this, e);
}
}
private void SetDragValue(Point mouseLocation) {
Rectangle client = ClientRectangle;
if (client.Contains(mouseLocation)) {
float percentage = (float)mouseLocation.X / (float)ClientRectangle.Width;
int newDragValue = (int)(percentage * (float)(max - min));
if (newDragValue != dragValue) {
int old = dragValue;
dragValue = newDragValue;
OptimizedInvalidate(old, dragValue);
}
}
else {
if (client.Y <= mouseLocation.Y && mouseLocation.Y <= client.Y + client.Height) {
if (mouseLocation.X <= client.X && mouseLocation.X > client.X - LeftRightBorder) {
int newDragValue = min;
if (newDragValue != dragValue) {
int old = dragValue;
dragValue = newDragValue;
OptimizedInvalidate(old, dragValue);
}
}
else if (mouseLocation.X >= client.X + client.Width && mouseLocation.X < client.X + client.Width + LeftRightBorder) {
int newDragValue = max;
if (newDragValue != dragValue) {
int old = dragValue;
dragValue = newDragValue;
OptimizedInvalidate(old, dragValue);
}
}
}
else {
if (dragValue != value) {
int old = dragValue;
dragValue = value;
OptimizedInvalidate(old, dragValue);
}
}
}
}
}
}