VCL控件属性编辑器类

在编写自己的控件过程中，在类中用__property定义的属性，系统会自动调用匹配的属性编辑器，如字符串、图片、字体等。当系统默认的属性编辑不符合应用的要求时，需要对属性编辑进行扩展。如需要选择一个文件或路径，此时VCL系统没有相应的编辑器。此时，只能通过继承TPropertyEditor类来进行扩展。

#include <designeditors.hpp>#include <DesignIntf.hpp>#include <vcleditors.hpp>//继承属性编辑器类class PACKAGE TMyPropertyEditor:public TPropertyEditor{    public:    void __fastcall SetValue(const AnsiString Value);    AnsiString __fastcall GetValue();    TPropertyAttributes __fastcall GetAttributes();    void __fastcall Edit(void);    __fastcall TMyPropertyEditor(const _di_IDesigner ADesigner, int APropCount);    __fastcall ~TMyPropertyEditor();};//覆盖父类方法:设置属性值void __fastcall TMyPropertyEditor::SetValue(const AnsiString Value){    ((TGraphicButtonControl1 * )GetComponent(0))->UIPicturePath->UIPath = Value;    ((TGraphicButtonControl1 * )GetComponent(0))->SetUIPicPath(ExtractFilePath(Value));}//---------------------------------------------------------------------------//覆盖父类方法:获取属性值AnsiString __fastcall TMyPropertyEditor::GetValue(){    AnsiString tmpS=((TGraphicButtonControl1 * )GetComponent(0))->UIPicturePath->UIPath;    ((TGraphicButtonControl1 * )GetComponent(0))->SetUIPicPath(ExtractFilePath(tmpS));        return tmpS;}//---------------------------------------------------------------------------__fastcall TMyPropertyEditor::TMyPropertyEditor(const _di_IDesigner ADesigner, int APropCount):TPropertyEditor(ADesigner,APropCount){   }//---------------------------------------------------------------------------__fastcall TMyPropertyEditor::~TMyPropertyEditor(){    //TODO: Add your source code here}//---------------------------------------------------------------------------//修改属性,弹出对话框TPropertyAttributes __fastcall TMyPropertyEditor::GetAttributes(){    return TPropertyAttributes()<<paDialog;}//---------------------------------------------------------------------------//通过对话框修改属性void __fastcall TMyPropertyEditor::Edit(void){      TOpenDialog * dg = new TOpenDialog(0);      if(dg->Execute())      {        ((TGraphicButtonControl1 * )GetComponent(0))->UIPicturePath->UIPath = ExtractFilePath(dg->FileName);        ((TGraphicButtonControl1 * )GetComponent(0))->SetUIPicPath(ExtractFilePath(dg->FileName));      }}//---------------------------------------------------------------------------//将特殊的属性字段封装到一个VCL类中，才能在控件的Register()函数中注册class TMyFile : public TPersistent{     AnsiString FFilePath;//这是文件路径,我们要用到的扩展属性  public:      TMyFile()      {         ;      }  __published:   __property AnsiString UIPath = {read = FFilePath,write = FFilePath};};控件的.cpp文件中注册过程如下：namespace Graphicbuttoncontrol1{        void __fastcall PACKAGE Register()        {                 //注册控件                 TComponentClass classes[1] = {__classid(TGraphicButtonControl1)};                 RegisterComponents("Samples", classes, 0);                 //注册属性编辑器                 RegisterPropertyEditor(                                    __typeinfo(TMyFile),//注意：自定义的封装类                       __classid(TGraphicButtonControl1),//控件类                                         "UIPicturePath",//控件的属性字体，能在IDE中可视编辑                            __classid(TMyPropertyEditor)//继承来的属性编辑类                 );        }}

编译控件的时候，在bpk工程的requires下添加designide.bpi