FMX画图实例

代码下载：

https://download.csdn.net/download/zhujianqiangqq/12394579

代码实例（电脑版、平板版）：

  1 unit Unit1;
  2 
  3 interface
  4 
  5 uses
  6   System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  7   FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, FMX.Objects,
  8   FMX.Controls.Presentation, FMX.StdCtrls, FMX.Edit;
  9 
 10 type
 11   TCanvasData = record  //定义绘制数据数组
 12     //画笔可设置的参数
 13     PenStartSize: Integer;      //画笔开始大小
 14     PenMinSize: Integer;        //画笔最小大小
 15     PenMaxSize: Integer;        //画笔最大大小
 16     PenMobileBorder: Integer;   //移动界限，超过这个值就改变笔大小值
 17     PenChangeValue: Integer;    //画笔每次改变的大小
 18     PenSizeChangeSpeed: Integer;//笔的改变速度，越小改变的速度越快
 19     //画图用到的参数
 20     PenCurrentSize: Integer;    //画笔当前大小
 21     PenLastPoint: TPointF;       //画笔最后的点
 22     PenMobileDistance: TPointF;  //画笔移动了多少距离
 23     MouseDownTab:Boolean;       //鼠标按下标记
 24     Yadd:Integer;
 25   end;
 26 
 27   TForm1 = class(TForm)
 28     IMOriginal: TImage;
 29     IMCanvas: TImage;
 30     Paint: TPanel;
 31     operate: TPanel;
 32     Label1: TLabel;
 33     Label2: TLabel;
 34     Label3: TLabel;
 35     Label4: TLabel;
 36     Label5: TLabel;
 37     Label6: TLabel;
 38     LEPenStartSize: TEdit;
 39     LEPenMinSize: TEdit;
 40     LEPenMaxSize: TEdit;
 41     LEPenMobileBorder: TEdit;
 42     LEPenChangeValue: TEdit;
 43     LEPenSizeChangeSpeed: TEdit;
 44     Timer1: TTimer;
 45     Button1: TButton;
 46     procedure IMCanvasMouseDown(Sender: TObject; Button: TMouseButton;
 47       Shift: TShiftState; X, Y: Single);
 48     procedure IMCanvasMouseMove(Sender: TObject; Shift: TShiftState; X,
 49       Y: Single);
 50     procedure FormCreate(Sender: TObject);
 51     procedure IMCanvasMouseUp(Sender: TObject; Button: TMouseButton;
 52       Shift: TShiftState; X, Y: Single);
 53     procedure Timer1Timer(Sender: TObject);
 54     procedure LEPenStartSizeChange(Sender: TObject);
 55     procedure FormResize(Sender: TObject);
 56     procedure Button1Click(Sender: TObject);
 57   private
 58     { Private declarations }
 59   public
 60     { Public declarations }
 61   end;
 62 
 63 var
 64   Form1: TForm1;
 65   MYCanvasData: TCanvasData;//定义画笔数据变量
 66 
 67 implementation
 68 uses
 69   System.UIConsts;
 70 
 71 {$R *.fmx}
 72 {$R *.LgXhdpiPh.fmx ANDROID}
 73 
 74 procedure TForm1.LEPenStartSizeChange(Sender: TObject);
 75 begin
 76   MYCanvasData.PenStartSize := StrToInt(LEPenStartSize.Text);   //开始笔头大小
 77   MYCanvasData.PenMinSize   := StrToInt(LEPenMinSize.Text);     //最小笔头
 78   MYCanvasData.PenMaxSize   := StrToInt(LEPenMaxSize.Text);     //最大笔头
 79   MYCanvasData.PenMobileBorder := StrToInt(LEPenMobileBorder.Text);    //移动距离  超过值时 改变笔头大小
 80   MYCanvasData.PenChangeValue  := StrToInt(LEPenChangeValue.Text);     //每次大小变动的单位
 81   MYCanvasData.PenCurrentSize  := StrToInt(LEPenSizeChangeSpeed.Text); //笔头 大小 改变的速度  越小速度越快
 82 end;
 83 
 84 procedure TForm1.Button1Click(Sender: TObject);
 85 begin
 86   IMCanvas.Bitmap := nil;
 87   IMCanvas.Bitmap.SetSize(Round(IMCanvas.Width), Round(IMCanvas.Height));
 88 end;
 89 
 90 procedure TForm1.FormCreate(Sender: TObject);
 91 begin
 92   IMOriginal.SendToBack;
 93 
 94   LEPenStartSize.Text  := '5';
 95   LEPenMinSize.Text    := '4';
 96   LEPenMaxSize.Text    := '10';
 97   LEPenMobileBorder.Text    := '5';
 98   LEPenChangeValue.Text     := '1';
 99   LEPenSizeChangeSpeed.Text := '3';
100 
101   MYCanvasData.PenStartSize := 5;
102   MYCanvasData.PenMinSize   := 4;
103   MYCanvasData.PenMaxSize   := 10;
104   MYCanvasData.PenMobileBorder := 5;
105   MYCanvasData.PenChangeValue  := 1;
106   MYCanvasData.PenSizeChangeSpeed  := 3;
107 
108   LEPenStartSize.OnChange := LEPenStartSizeChange;
109   LEPenMinSize.OnChange   := LEPenStartSizeChange;
110   LEPenMaxSize.OnChange   := LEPenStartSizeChange;
111   LEPenMobileBorder.OnChange    := LEPenStartSizeChange;
112   LEPenChangeValue.OnChange     := LEPenStartSizeChange;
113   LEPenSizeChangeSpeed.OnChange := LEPenStartSizeChange;
114 
115   IMCanvas.Bitmap.SetSize(Round(IMCanvas.Width), Round(IMCanvas.Height));
116 //  IMCanvas.Bitmap.Clear(TAlphaColors.White);
117 end;
118 
119 procedure TForm1.FormResize(Sender: TObject);
120 begin
121   IMCanvas.Bitmap.SetSize(Round(IMCanvas.Width), Round(IMCanvas.Height));
122 end;
123 
124 procedure TForm1.IMCanvasMouseDown(Sender: TObject; Button: TMouseButton;
125   Shift: TShiftState; X, Y: Single);
126 begin
127   case Button of
128     TMouseButton.mbLeft:
129     begin
130       MYCanvasData.PenCurrentSize := MYCanvasData.PenStartSize;
131       MYCanvasData.PenMobileDistance.X := -1;
132       MYCanvasData.PenLastPoint.X := X;
133       MYCanvasData.PenLastPoint.Y := Y;
134       //Yadd:=1;
135       MYCanvasData.MouseDownTab := True;
136     end;
137     TMouseButton.mbRight: ;
138     TMouseButton.mbMiddle:  ;
139   end;
140 end;
141 
142 procedure TForm1.IMCanvasMouseMove(Sender: TObject; Shift: TShiftState; X,
143   Y: Single);
144 var
145   p1, p2: TPointF;
146 begin
147   Form1.Caption:='当前笔头大小:' + IntToStr(MYCanvasData.PenCurrentSize);
148   if MYCanvasData.MouseDownTab then
149   begin
150     IMCanvas.Bitmap.Canvas.BeginScene;
151     IMCanvas.Bitmap.Canvas.Stroke.Thickness := MYCanvasData.PenCurrentSize;
152     IMCanvas.Bitmap.Canvas.Stroke.Cap := TStrokeCap.Round;
153 
154     p1 := TPointF.Create(MYCanvasData.PenLastPoint.X, MYCanvasData.PenLastPoint.Y);
155     p2 := TPointF.Create(X, Y);
156 
157     IMCanvas.Bitmap.Canvas.DrawLine(p1, p2, 100);
158     IMCanvas.Bitmap.Canvas.EndScene;
159 
160     MYCanvasData.PenLastPoint.X := X;
161     MYCanvasData.PenLastPoint.Y := Y;
162   end;
163 end;
164 
165 procedure TForm1.IMCanvasMouseUp(Sender: TObject; Button: TMouseButton;
166   Shift: TShiftState; X, Y: Single);
167 begin
168   case Button of
169     TMouseButton.mbLeft: MYCanvasData.MouseDownTab := False;
170     TMouseButton.mbRight:;
171     TMouseButton.mbMiddle:;
172   end;
173 end;
174 
175 procedure TForm1.Timer1Timer(Sender: TObject);
176 begin
177   if  MYCanvasData.MouseDownTab then
178   Begin
179     if MYCanvasData.PenMobileDistance.X > -1 then
180     begin
181       Inc(MYCanvasData.Yadd);
182       if (Abs(MYCanvasData.PenMobileDistance.X - MYCanvasData.PenLastPoint.X) < MYCanvasData.PenMobileBorder) and
183          (Abs(MYCanvasData.PenMobileDistance.Y - MYCanvasData.PenLastPoint.Y) < MYCanvasData.PenMobileBorder) then
184       Begin
185         if (MYCanvasData.Yadd >= MYCanvasData.PenSizeChangeSpeed) then
186           if (MYCanvasData.PenCurrentSize < MYCanvasData.PenMaxSize) then
187           begin
188             MYCanvasData.PenCurrentSize := MYCanvasData.PenCurrentSize + MYCanvasData.PenChangeValue;
189             MYCanvasData.Yadd:=1;
190           end;
191       end
192       else
193       begin
194         if (MYCanvasData.Yadd >= MYCanvasData.PenSizeChangeSpeed) then
195           if (MYCanvasData.PenCurrentSize > MYCanvasData.PenMinSize) then
196           begin
197             MYCanvasData.PenCurrentSize := MYCanvasData.PenCurrentSize - MYCanvasData.PenChangeValue;
198             MYCanvasData.Yadd := 1;
199           end;
200       end;
201     end;
202     MYCanvasData.PenMobileDistance.X := MYCanvasData.PenLastPoint.X;
203     MYCanvasData.PenMobileDistance.Y := MYCanvasData.PenLastPoint.Y;
204   End;
205 end;
206 
207 end.

代码实例（手机版）：

 1 procedure TForm1.FormCreate(Sender: TObject);
 2 begin
 3   IMOriginal.SendToBack;
 4 
 5   LEPenStartSize.Text  := '2';//'5';
 6   LEPenMinSize.Text    := '2';//'4';
 7   LEPenMaxSize.Text    := '5';//'10';
 8   LEPenMobileBorder.Text    := '20';//'5';
 9   LEPenChangeValue.Text     := '1';//'1';
10   LEPenSizeChangeSpeed.Text := '1';
11 
12   MYCanvasData.PenStartSize := 2;
13   MYCanvasData.PenMinSize   := 2;
14   MYCanvasData.PenMaxSize   := 5;
15   MYCanvasData.PenMobileBorder := 20;//'5';
16   MYCanvasData.PenChangeValue  := 1;
17   MYCanvasData.PenSizeChangeSpeed  := 1;
18 
19   LEPenStartSize.OnChange := LEPenStartSizeChange;
20   LEPenMinSize.OnChange   := LEPenStartSizeChange;
21   LEPenMaxSize.OnChange   := LEPenStartSizeChange;
22   LEPenMobileBorder.OnChange    := LEPenStartSizeChange;
23   LEPenChangeValue.OnChange     := LEPenStartSizeChange;
24   LEPenSizeChangeSpeed.OnChange := LEPenStartSizeChange;
25 
26   IMCanvas.Bitmap.SetSize(Round(IMCanvas.Width), Round(IMCanvas.Height));
27 //  IMCanvas.Bitmap.Clear(TAlphaColors.White);
28 end;
29 
30 procedure TForm1.IMCanvasMouseMove(Sender: TObject; Shift: TShiftState; X,
31   Y: Single);
32 var
33   p1, p2: TPointF;
34 begin
35   Form1.Caption:='当前笔头大小:' + FloatToStr(MYCanvasData.PenCurrentSize);
36   if MYCanvasData.MouseDownTab then
37   begin
38     IMCanvas.Bitmap.Canvas.BeginScene;
39     IMCanvas.Bitmap.Canvas.Stroke.Thickness := MYCanvasData.PenCurrentSize;
40     IMCanvas.Bitmap.Canvas.Stroke.Cap := TStrokeCap.Round;
41 
42     p1 := TPointF.Create(MYCanvasData.PenLastPoint.X/3, MYCanvasData.PenLastPoint.Y/3);
43     p2 := TPointF.Create(X/3, Y/3);
44 
45     IMCanvas.Bitmap.Canvas.DrawLine(p1, p2, 1);
46     IMCanvas.Bitmap.Canvas.EndScene;
47 
48     MYCanvasData.PenLastPoint.X := X;
49     MYCanvasData.PenLastPoint.Y := Y;
50   end;
51 end;