方法 : グラデーションの塗りつぶしを表示します。
[このドキュメントはプレビュー版であり、後のリリースで変更されることがあります。 空白のトピックは、プレースホルダーとして挿入されています。]
グラデーションの塗りつぶしを表示し、カラフルな見栄えのグラフィックスをアプリケーションに追加できます。 カスタム コントロールでは、フォームの背景としてに、グラデーション塗りつぶしを表示するコード例を次に示します。
プロシージャ
グラデーションの塗りつぶしを表示するには
Visual Studio でスマート デバイス プロジェクトを作成します。
Gradientfill GradientFilledButton クラスとプロジェクトに追加します。
NotInheritable Public Class GradientFill ' This method wraps the PInvoke to GradientFill. ' Parmeters: ' gr - The Graphics object we are filling ' rc - The rectangle to fill ' startColor - The starting color for the fill ' endColor - The ending color for the fill ' fillDir - The direction to fill ' ' Returns true if the call to GradientFill succeeded; false ' otherwise.PublicSharedFunction Fill(ByVal gr As Graphics, ByVal rc As Rectangle, ByVal startColor As Color, _ ByVal endColor As Color, ByVal fillDir As FillDirection) AsBoolean ' Initialize the data to be used in the call to GradientFill.Dim tva(1) As Win32Helper.TRIVERTEX tva(0) = New Win32Helper.TRIVERTEX(rc.X, rc.Y, startColor) tva(1) = New Win32Helper.TRIVERTEX(rc.Right, rc.Bottom, endColor) Dim gra() As Win32Helper.GRADIENT_RECT = {New Win32Helper.GRADIENT_RECT(0, 1)} ' Get the hDC from the Graphics object.Dim hdc As IntPtr = gr.GetHdc() ' PInvoke to GradientFill.Dim b AsBoolean b = Win32Helper.GradientFill(hdc, tva, CType(tva.Length, System.Int32), gra, CType(gra.Length, System.Int32), CType(fillDir, System.Int32)) System.Diagnostics.Debug.Assert(b, String.Format("GradientFill failed: {0}", System.Runtime.InteropServices.Marshal.GetLastWin32Error())) ' Release the hDC from the Graphics object. gr.ReleaseHdc(hdc) Return b EndFunction ' The direction to the GradientFill will followPublicEnum FillDirection ' The fill goes horizontally LeftToRight = Win32Helper.GRADIENT_FILL_RECT_H ' The fill goes vertically TopToBottom = Win32Helper.GRADIENT_FILL_RECT_V EndEnumEndClass ' Extends the standard button control and performs' custom drawing with a GradientFill background.PublicClass GradientFilledButton Inherits Control Private components As System.ComponentModel.IContainer = NothingPublicSubNew() components = New System.ComponentModel.Container() Me.Font = New Font(Me.Font.Name, Me.Font.Size, FontStyle.Bold) EndSub ' Controls the direction in which the button is filled.PublicProperty FillDirection() As GradientFill.FillDirection GetReturn fillDirectionValue EndGetSet(ByVal value As GradientFill.FillDirection) fillDirectionValue = value Invalidate() EndSetEndPropertyPrivate fillDirectionValue As GradientFill.FillDirection ' The start color for the GradientFill. This is the color ' at the left or top of the control depeneding on the value ' of the FillDirection property.PublicProperty StartColor() As Color GetReturn startColorValue EndGetSet(ByVal value As Color) startColorValue = value Invalidate() EndSetEndPropertyPrivate startColorValue As Color = Color.Red ' The end color for the GradientFill. This is the color ' at the right or bottom of the control depending on the value ' of the FillDirection propertyPublicProperty EndColor() As Color GetReturn endColorValue EndGetSet(ByVal value As Color) endColorValue = value Invalidate() EndSetEndPropertyPrivate endColorValue As Color = Color.Blue ' This is the offset from the left or top edge ' of the button to start the gradient fill.PublicProperty StartOffset() AsIntegerGetReturn startOffsetValue EndGetSet(ByVal value AsInteger) startOffsetValue = value Invalidate() EndSetEndPropertyPrivate startOffsetValue AsInteger ' This is the offset from the right or bottom edge ' of the button to end the gradient fill.PublicProperty EndOffset() AsIntegerGetReturn endOffsetValue EndGetSet(ByVal value AsInteger) endOffsetValue = value Invalidate() EndSetEndPropertyPrivate endOffsetValue AsInteger ' Used to double-buffer our drawing to avoid flicker ' between painting the background, border, focus-rect ' and the text of the control.PrivateProperty DoubleBufferImage() As Bitmap GetIf bmDoubleBuffer IsNothingThen bmDoubleBuffer = New Bitmap(Me.ClientSize.Width, Me.ClientSize.Height) EndIfReturn bmDoubleBuffer EndGetSet(ByVal value As Bitmap) IfNot (bmDoubleBuffer IsNothing) Then bmDoubleBuffer.Dispose() EndIf bmDoubleBuffer = value EndSetEndPropertyPrivate bmDoubleBuffer As Bitmap ' Called when the control is resized. When that happens, ' recreate the bitmap used for double-buffering.ProtectedOverridesSub OnResize(ByVal e As EventArgs) DoubleBufferImage = New Bitmap(Me.ClientSize.Width, Me.ClientSize.Height) MyBase.OnResize(e) EndSub ' Called when the control gets focus. Need to repaint ' the control to ensure the focus rectangle is drawn correctly.ProtectedOverridesSub OnGotFocus(ByVal e As EventArgs) MyBase.OnGotFocus(e) Me.Invalidate() EndSub ' Called when the control loses focus. Need to repaint ' the control to ensure the focus rectangle is removed.ProtectedOverridesSub OnLostFocus(ByVal e As EventArgs) MyBase.OnLostFocus(e) Me.Invalidate() EndSubProtectedOverridesSub OnMouseMove(ByVal e As MouseEventArgs) IfMe.Capture ThenDim coord AsNew Point(e.X, e.Y) IfMe.ClientRectangle.Contains(coord) <> Me.ClientRectangle.Contains(lastCursorCoordinates) Then DrawButton(Me.ClientRectangle.Contains(coord)) EndIf lastCursorCoordinates = coord EndIfMyBase.OnMouseMove(e) EndSub ' The coordinates of the cursor the last time ' there was a MouseUp or MouseDown message.Private lastCursorCoordinates As Point ProtectedOverridesSub OnMouseDown(ByVal e As MouseEventArgs) If e.Button = System.Windows.Forms.MouseButtons.Left Then ' Start capturing the mouse inputMe.Capture = True ' Get the focus because button is clicked.Me.Focus() ' draw the button DrawButton(True) EndIfMyBase.OnMouseDown(e) EndSubProtectedOverridesSub OnMouseUp(ByVal e As MouseEventArgs) Me.Capture = False DrawButton(False) MyBase.OnMouseUp(e) EndSubPrivate bGotKeyDown AsBoolean = FalseProtectedOverridesSub OnKeyDown(ByVal e As KeyEventArgs) bGotKeyDown = TrueSelectCase e.KeyCode Case Keys.Space, Keys.Enter DrawButton(True) Case Keys.Up, Keys.Left Me.Parent.SelectNextControl(Me, False, False, True, True) Case Keys.Down, Keys.Right Me.Parent.SelectNextControl(Me, True, False, True, True) CaseElse bGotKeyDown = FalseMyBase.OnKeyDown(e) EndSelectEndSubProtectedOverridesSub OnKeyUp(ByVal e As KeyEventArgs) SelectCase e.KeyCode Case Keys.Space, Keys.Enter If bGotKeyDown Then DrawButton(False) OnClick(EventArgs.Empty) bGotKeyDown = FalseEndIfCaseElseMyBase.OnKeyUp(e) EndSelectEndSub ' Override this method with no code to avoid flicker.ProtectedOverridesSub OnPaintBackground(ByVal e As PaintEventArgs) EndSubProtectedOverridesSub OnPaint(ByVal e As PaintEventArgs) DrawButton(e.Graphics, Me.Capture AndAlsoMe.ClientRectangle.Contains(lastCursorCoordinates)) EndSub ' Gets a Graphics object for the provided window handle ' and then calls DrawButton(Graphics, bool). ' If pressed is true, the button is drawn ' in the depressed state.OverloadsSub DrawButton(ByVal pressed AsBoolean) Dim gr As Graphics = Me.CreateGraphics() DrawButton(gr, pressed) gr.Dispose() EndSub ' Draws the button on the specified Grapics ' in the specified state. ' ' Parameters: ' gr - The Graphics object on which to draw the button. ' pressed - If true, the button is drawn in the depressed state.OverloadsSub DrawButton(ByVal gr As Graphics, ByVal pressed AsBoolean) ' Get a Graphics object from the background image.Dim gr2 As Graphics = Graphics.FromImage(DoubleBufferImage) ' Fill solid up until where the gradient fill starts.If startOffsetValue > 0 ThenIf fillDirectionValue = GradientFill.FillDirection.LeftToRight ThenIf pressed Then gr2.FillRectangle(New SolidBrush(EndColor), 0, 0, startOffsetValue, Height) Else gr2.FillRectangle(New SolidBrush(StartColor), 0, 0, startOffsetValue, Height) EndIfElseIf pressed Then gr2.FillRectangle(New SolidBrush(EndColor), 0, 0, Width, startOffsetValue) Else gr2.FillRectangle(New SolidBrush(StartColor), 0, 0, Width, startOffsetValue) EndIfEndIfEndIf ' Draw the gradient fill.Dim rc As Rectangle = Me.ClientRectangle If fillDirectionValue = GradientFill.FillDirection.LeftToRight Then rc.X = startOffsetValue rc.Width = rc.Width - startOffsetValue - endOffsetValue Else rc.Y = startOffsetValue rc.Height = rc.Height - startOffsetValue - endOffsetValue EndIfIf pressed Then GradientFill.Fill(gr2, rc, endColorValue, startColorValue, fillDirectionValue) Else GradientFill.Fill(gr2, rc, startColorValue, endColorValue, fillDirectionValue) EndIf ' Fill solid from the end of the gradient fill ' to the edge of the button.If endOffsetValue > 0 ThenIf fillDirectionValue = GradientFill.FillDirection.LeftToRight ThenIf pressed Then gr2.FillRectangle(New SolidBrush(StartColor), rc.X + rc.Width, 0, endOffsetValue, Height) Else gr2.FillRectangle(New SolidBrush(EndColor), rc.X + rc.Width, 0, endOffsetValue, Height) EndIfElseIf pressed Then gr2.FillRectangle(New SolidBrush(StartColor), 0, rc.Y + rc.Height, Width, endOffsetValue) Else gr2.FillRectangle(New SolidBrush(StartColor), 0, rc.Y + rc.Height, Width, endOffsetValue) EndIfEndIfEndIf ' Draw the text.Dim sf AsNew StringFormat() sf.Alignment = StringAlignment.Center sf.LineAlignment = StringAlignment.Center gr2.DrawString(Me.Text, Me.Font, New SolidBrush(Me.ForeColor), Me.ClientRectangle, sf) ' Draw the border. ' Need to shrink the width and height by 1 otherwise ' there will be no border on the right or bottom. rc = Me.ClientRectangle rc.Width -= 1 rc.Height -= 1 Dim pen AsNew Pen(SystemColors.WindowFrame) gr2.DrawRectangle(pen, rc) ' Draw from the background image onto the screen. gr.DrawImage(DoubleBufferImage, 0, 0) gr2.Dispose() EndSubProtectedOverridesSub Dispose(ByVal disposing AsBoolean) If disposing AndAlsoNot (components IsNothing) Then components.Dispose() EndIfMyBase.Dispose(disposing) EndSubEndClasspublic sealed class GradientFill { // This method wraps the PInvoke to GradientFill.// Parmeters:// gr - The Graphics object we are filling// rc - The rectangle to fill// startColor - The starting color for the fill// endColor - The ending color for the fill// fillDir - The direction to fill//// Returns true if the call to GradientFill succeeded; false// otherwise.publicstaticbool Fill( Graphics gr, Rectangle rc, Color startColor, Color endColor, FillDirection fillDir) { // Initialize the data to be used in the call to GradientFill. Win32Helper.TRIVERTEX[] tva = new Win32Helper.TRIVERTEX[2]; tva[0] = new Win32Helper.TRIVERTEX(rc.X, rc.Y, startColor); tva[1] = new Win32Helper.TRIVERTEX(rc.Right, rc.Bottom, endColor); Win32Helper.GRADIENT_RECT[] gra = new Win32Helper.GRADIENT_RECT[] { new Win32Helper.GRADIENT_RECT(0, 1)}; // Get the hDC from the Graphics object. IntPtr hdc = gr.GetHdc(); // PInvoke to GradientFill.bool b; b = Win32Helper.GradientFill( hdc, tva, (uint)tva.Length, gra, (uint)gra.Length, (uint)fillDir); System.Diagnostics.Debug.Assert(b, string.Format( "GradientFill failed: {0}", System.Runtime.InteropServices.Marshal.GetLastWin32Error())); // Release the hDC from the Graphics object. gr.ReleaseHdc(hdc); return b; } // The direction to the GradientFill will followpublicenum FillDirection { //// The fill goes horizontally// LeftToRight = Win32Helper.GRADIENT_FILL_RECT_H, //// The fill goes vertically// TopToBottom = Win32Helper.GRADIENT_FILL_RECT_V } } // Extends the standard button control and performs// custom drawing with a GradientFill background.publicclass GradientFilledButton : Control { private System.ComponentModel.IContainer components = null; public GradientFilledButton() { components = new System.ComponentModel.Container(); this.Font = new Font(this.Font.Name, this.Font.Size, FontStyle.Bold); } // Controls the direction in which the button is filled.public GradientFill.FillDirection FillDirection { get { return fillDirectionValue; } set { fillDirectionValue = value; Invalidate(); } } private GradientFill.FillDirection fillDirectionValue; // The start color for the GradientFill. This is the color// at the left or top of the control depeneding on the value// of the FillDirection property.public Color StartColor { get { return startColorValue; } set { startColorValue = value; Invalidate(); } } private Color startColorValue = Color.Red; // The end color for the GradientFill. This is the color// at the right or bottom of the control depending on the value// of the FillDirection propertypublic Color EndColor { get { return endColorValue; } set { endColorValue = value; Invalidate(); } } private Color endColorValue = Color.Blue; // This is the offset from the left or top edge// of the button to start the gradient fill.publicint StartOffset { get { return startOffsetValue; } set { startOffsetValue = value; Invalidate(); } } privateint startOffsetValue; // This is the offset from the right or bottom edge// of the button to end the gradient fill.publicint EndOffset { get { return endOffsetValue; } set { endOffsetValue = value; Invalidate(); } } privateint endOffsetValue; // Used to double-buffer our drawing to avoid flicker// between painting the background, border, focus-rect// and the text of the control.private Bitmap DoubleBufferImage { get { if (bmDoubleBuffer == null) bmDoubleBuffer = new Bitmap( this.ClientSize.Width, this.ClientSize.Height); return bmDoubleBuffer; } set { if (bmDoubleBuffer != null) bmDoubleBuffer.Dispose(); bmDoubleBuffer = value; } } private Bitmap bmDoubleBuffer; // Called when the control is resized. When that happens,// recreate the bitmap used for double-buffering.protectedoverridevoid OnResize(EventArgs e) { DoubleBufferImage = new Bitmap( this.ClientSize.Width, this.ClientSize.Height); base.OnResize(e); } // Called when the control gets focus. Need to repaint// the control to ensure the focus rectangle is drawn correctly.protectedoverridevoid OnGotFocus(EventArgs e) { base.OnGotFocus(e); this.Invalidate(); } //// Called when the control loses focus. Need to repaint// the control to ensure the focus rectangle is removed.protectedoverridevoid OnLostFocus(EventArgs e) { base.OnLostFocus(e); this.Invalidate(); } protectedoverridevoid OnMouseMove(MouseEventArgs e) { if (this.Capture) { Point coord = new Point(e.X, e.Y); if (this.ClientRectangle.Contains(coord) != this.ClientRectangle.Contains(lastCursorCoordinates)) { DrawButton(this.ClientRectangle.Contains(coord)); } lastCursorCoordinates = coord; } base.OnMouseMove(e); } // The coordinates of the cursor the last time// there was a MouseUp or MouseDown message. Point lastCursorCoordinates; protectedoverridevoid OnMouseDown(MouseEventArgs e) { if (e.Button == MouseButtons.Left) { // Start capturing the mouse inputthis.Capture = true; // Get the focus because button is clicked.this.Focus(); // draw the button DrawButton(true); } base.OnMouseDown(e); } protectedoverridevoid OnMouseUp(MouseEventArgs e) { this.Capture = false; DrawButton(false); base.OnMouseUp(e); } bool bGotKeyDown = false; protectedoverridevoid OnKeyDown(KeyEventArgs e) { bGotKeyDown = true; switch (e.KeyCode) { case Keys.Space: case Keys.Enter: DrawButton(true); break; case Keys.Up: case Keys.Left: this.Parent.SelectNextControl(this, false, false, true, true); break; case Keys.Down: case Keys.Right: this.Parent.SelectNextControl(this, true, false, true, true); break; default: bGotKeyDown = false; base.OnKeyDown(e); break; } } protectedoverridevoid OnKeyUp(KeyEventArgs e) { switch (e.KeyCode) { case Keys.Space: case Keys.Enter: if (bGotKeyDown) { DrawButton(false); OnClick(EventArgs.Empty); bGotKeyDown = false; } break; default: base.OnKeyUp(e); break; } } // Override this method with no code to avoid flicker.protectedoverridevoid OnPaintBackground(PaintEventArgs e) { } protectedoverridevoid OnPaint(PaintEventArgs e) { DrawButton(e.Graphics, this.Capture && (this.ClientRectangle.Contains(lastCursorCoordinates))); } //// Gets a Graphics object for the provided window handle// and then calls DrawButton(Graphics, bool).//// If pressed is true, the button is drawn// in the depressed state.void DrawButton(bool pressed) { Graphics gr = this.CreateGraphics(); DrawButton(gr, pressed); gr.Dispose(); } // Draws the button on the specified Grapics// in the specified state.//// Parameters:// gr - The Graphics object on which to draw the button.// pressed - If true, the button is drawn in the depressed state.void DrawButton(Graphics gr, bool pressed) { // Get a Graphics object from the background image. Graphics gr2 = Graphics.FromImage(DoubleBufferImage); // Fill solid up until where the gradient fill starts.if (startOffsetValue > 0) { if (fillDirectionValue == GradientFill.FillDirection.LeftToRight) { gr2.FillRectangle( new SolidBrush(pressed ? EndColor : StartColor), 0, 0, startOffsetValue, Height); } else { gr2.FillRectangle( new SolidBrush(pressed ? EndColor : StartColor), 0, 0, Width, startOffsetValue); } } // Draw the gradient fill. Rectangle rc = this.ClientRectangle; if (fillDirectionValue == GradientFill.FillDirection.LeftToRight) { rc.X = startOffsetValue; rc.Width = rc.Width - startOffsetValue - endOffsetValue; } else { rc.Y = startOffsetValue; rc.Height = rc.Height - startOffsetValue - endOffsetValue; } GradientFill.Fill( gr2, rc, pressed ? endColorValue : startColorValue, pressed ? startColorValue : endColorValue, fillDirectionValue); // Fill solid from the end of the gradient fill// to the edge of the button.if (endOffsetValue > 0) { if (fillDirectionValue == GradientFill.FillDirection.LeftToRight) { gr2.FillRectangle( new SolidBrush(pressed ? StartColor : EndColor), rc.X + rc.Width, 0, endOffsetValue, Height); } else { gr2.FillRectangle( new SolidBrush(pressed ? StartColor : EndColor), 0, rc.Y + rc.Height, Width, endOffsetValue); } } // Draw the text. StringFormat sf = new StringFormat(); sf.Alignment = StringAlignment.Center; sf.LineAlignment = StringAlignment.Center; gr2.DrawString(this.Text, this.Font, new SolidBrush(this.ForeColor), this.ClientRectangle, sf); // Draw the border.// Need to shrink the width and height by 1 otherwise// there will be no border on the right or bottom. rc = this.ClientRectangle; rc.Width--; rc.Height--; Pen pen = new Pen(SystemColors.WindowFrame); gr2.DrawRectangle(pen, rc); // Draw from the background image onto the screen. gr.DrawImage(DoubleBufferImage, 0, 0); gr2.Dispose(); } protectedoverridevoid Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } }プラットフォームを含む、プロジェクト、Win32Helper クラスを呼び出すし、ネイティブ コードの相互運用性構造体追加します。
Public NotInheritable Class Win32Helper PublicStructure TRIVERTEX Public x AsIntegerPublic y AsIntegerPublic Red As System.Int16 Public Green As System.Int16 Public Blue As System.Int16 Public Alpha As System.Int16 PublicSubNew(ByVal x AsInteger, ByVal y AsInteger, ByVal color As Color) MyClass.New(x, y, color.R, color.G, color.B, color.A) EndSubPublicSubNew(ByVal x AsInteger, ByVal y AsInteger, ByVal red As System.Int16, ByVal green As System.Int16, ByVal blue As System.Int16, ByVal alpha As System.Int16) Me.x = x Me.y = y Me.Red = CInt(red << 8) Me.Green = CInt(green << 8) Me.Blue = CInt(blue << 8) Me.Alpha = CInt(alpha << 8) EndSubEndStructurePublicStructure GRADIENT_RECT Public UpperLeft As System.Int32 Public LowerRight As System.Int32 PublicSubNew(ByVal ul As System.Int32, ByVal lr As System.Int32) Me.UpperLeft = ul Me.LowerRight = lr EndSubEndStructurePublicDeclareFunction GradientFill Lib"coredll.dll"Alias"GradientFill" (ByVal hdc As IntPtr, _ ByVal pVertex() As TRIVERTEX, ByVal dwNumVertex AsInteger, _ ByVal pMesh() As GRADIENT_RECT, ByVal dwNumMesh AsInteger, _ ByVal dwMode AsInteger) AsBooleanPublicConst GRADIENT_FILL_RECT_H AsInteger = &H0 PublicConst GRADIENT_FILL_RECT_V AsInteger = &H1 EndClasspublic sealed class Win32Helper { publicstruct TRIVERTEX { publicint x; publicint y; publicushort Red; publicushort Green; publicushort Blue; publicushort Alpha; public TRIVERTEX(int x, int y, Color color) : this(x, y, color.R, color.G, color.B, color.A) { } public TRIVERTEX( int x, int y, ushort red, ushort green, ushort blue, ushort alpha) { this.x = x; this.y = y; this.Red = (ushort)(red << 8); this.Green = (ushort)(green << 8); this.Blue = (ushort)(blue << 8); this.Alpha = (ushort)(alpha << 8); } } publicstruct GRADIENT_RECT { publicuint UpperLeft; publicuint LowerRight; public GRADIENT_RECT(uint ul, uint lr) { this.UpperLeft = ul; this.LowerRight = lr; } } [DllImport("coredll.dll", SetLastError = true, EntryPoint = "GradientFill")] publicexternstaticbool GradientFill( IntPtr hdc, TRIVERTEX[] pVertex, uint dwNumVertex, GRADIENT_RECT[] pMesh, uint dwNumMesh, uint dwMode); publicconstint GRADIENT_FILL_RECT_H = 0x00000000; publicconstint GRADIENT_FILL_RECT_V = 0x00000001; }種類 gfButtonGradientFilledButton をという名前のフォーム変数を宣言します。
Private gfButton As GradientFilledButtonprivate GradientFilledButton gfButton;Form1 クラスのコンストラクターに、グラデーションの塗りつぶされたボタン カスタム コントロールの初期化、次のコードを追加します。 このコードは、InitializeComponent メソッドを呼び出す従ってください。 開始および終了色のグラデーションの塗りつぶしと TopToBottom または LeftToRight 塗りつぶし方向を指定できます。
InitializeComponent() Me.gfButton = New GradientFilledButton() Me.gfButton.Location = New System.Drawing.Point(71, 24) Me.gfButton.Name = "gfButton"Me.gfButton.Size = New System.Drawing.Size(100, 23) Me.gfButton.TabIndex = 1 Me.gfButton.Text = "Button Test"AddHandlerMe.gfButton.Click, AddressOfMe.gfButton_Click ' Select desired start color, end color, and fill direction.Me.gfButton.StartColor = System.Drawing.Color.SlateBlue Me.gfButton.EndColor = System.Drawing.Color.LightCyan gfButton.FillDirection = GradientFill.FillDirection.LeftToRight Me.Controls.Add(gfButton)InitializeComponent(); this.gfButton = new GradientFilledButton(); this.gfButton.Location = new System.Drawing.Point(71, 24); this.gfButton.Name = "gfButton"; this.gfButton.Size = new System.Drawing.Size(100, 23); this.gfButton.TabIndex = 1; this.gfButton.Text = "Button Test"; this.gfButton.Click += new System.EventHandler(this.gfButton_Click); // Select desired start color, end color, and fill direction.this.gfButton.StartColor = System.Drawing.Color.SlateBlue; this.gfButton.EndColor = System.Drawing.Color.LightCyan; gfButton.FillDirection = GradientFill.FillDirection.LeftToRight; this.Controls.Add(gfButton);イベント処理フォームにボタンの Click イベント コードを追加します。
Private Sub gfButton_Click(ByVal sender AsObject, ByVal e As System.EventArgs) Dim control As Control = sender System.Diagnostics.Debug.Assert( Not (control IsNothing)) MessageBox.Show("Clicked", "Click event handler") EndSubvoid gfButton_Click(object sender, System.EventArgs e) { Control control = sender as Control; System.Diagnostics.Debug.Assert(control != null); MessageBox.Show("Clicked", "Click event handler"); }グラデーションの塗りつぶしパターンを持つ、フォームの背景を描画するには、OnPaint メソッド オーバーライドします。 このコードは、GradientFill クラスは、 GradientFilledButton クラスではないで使用します。
' Paints the background of the form with a GradientFill pattern. Protected Overrides Sub OnPaintBackground(ByVal e As PaintEventArgs) ' On Windows Mobile Pocket PC 2003, the call to GradientFill ' fails with GetLastError() returning 87 (ERROR_INVALID_PARAMETER) ' when e.Graphics is used. ' Instead, fill into a bitmap and then draw that onto e.Graphics.Dim bm AsNew Bitmap(Width, Height) Dim gr As Graphics = System.Drawing.Graphics.FromImage(bm) GradientFill.Fill(gr, Me.ClientRectangle, Color.LightCyan, Color.SlateBlue, GradientFill.FillDirection.TopToBottom) e.Graphics.DrawImage(bm, 0, 0) gr.Dispose() bm.Dispose() EndSub// Paints the background of the form with a GradientFill pattern. protected override void OnPaintBackground(PaintEventArgs e) { // On Windows Mobile Pocket PC 2003, the call to GradientFill// fails with GetLastError() returning 87 (ERROR_INVALID_PARAMETER)// when e.Graphics is used.// Instead, fill into a bitmap and then draw that onto e.Graphics. Bitmap bm = new Bitmap(Width, Height); Graphics gr = System.Drawing.Graphics.FromImage(bm); GradientFill.Fill( gr, this.ClientRectangle, Color.LightCyan, Color.SlateBlue, GradientFill.FillDirection.TopToBottom); e.Graphics.DrawImage(bm, 0, 0); gr.Dispose(); bm.Dispose(); }ビルドしてアプリケーションを展開します。
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