Delphi 复习代码

1、取得可文件路径 

Path := ExtractFilePath(Application.ExeName); //取得可执行文件路径 TXMLDocument.Create(ExtractFilePath(Application.ExeName)+ '001.xml'）

2、DisableControls EnableControls

ClientDataSet.DisableControls;

...

for I := 0 to 10000 do

begin

  ClientDataSet.Append;

  ...

  ClientDataSet.Post;

end;...

ClientDataSet.EnableControls

3、XML的解析

<?xml version="1.0" encoding="utf-8"?>

<root>

  <info id="id1" name="name1" />

  <info id="id2" name="name2" />

</root> 



var

  XMLDoc: TXMLDocument;

  iNode, tmpNode: IXMLNode;

begin

  with ClientDataSet1 do

  begin

    FieldDefs.Add('id',ftString,250);

    FieldDefs.Add('name',ftString,100);

    CreateDataSet;

  end;



  XMLDoc:= TXMLDocument.Create(Owner);

  XMLDoc.FileName:='E:\1.xml';

  XMLDoc.Active:=True;

  iNode := XMLDoc.DocumentElement.ChildNodes.First;

  while iNode<> nil do

  begin

    ClientDataSet1.AppendRecord([iNode.Attributes['id'],iNode.Attributes['name']]);

    iNode:= iNode.NextSibling;

  end;

  XMLDoc.Free;

end;

 3、DelPhi 动态给ComBoBox赋值，从ComBoBox中取值 

1、把数据库中的项目信息（项目名称、项目编号）动态赋给ComBoBox



 cbProjectName.Items.Clear;

   with adoQryProject do

   begin

     First;

     while not Eof do

     begin

       ProjectNameStr := fieldByName('ProjectName').AsString;

       if Trim(ProjectNameStr) <> '' then

         cbProjectName.Items.AddObject(ProjectNameStr, TObject(fieldByName('ProjectID').AsInteger));

       Next;

     end;

   end; 



2、读取ComBoBox中的值



ProjectID:= IInteger(cbProjectName.Items.Objects[cbProjectName.ItemIndex]);

ProjectName:= cbProjectName.Text; 



3、快速定位到某个字段或数据:



1>、设置Combobox控件的AutoComplete属性为true即可; 



2>、combobox1.ItemIndex := Combobox1.Items.IndexOf(trim(edit1.text));

4、图片的存取

1、存图片到数据库 

var

   PicStream: TMemoryStream;



 if imgBugPic.Picture.Graphic <> nil then

  begin

    PicStream := TMemoryStream.Create; //  创建内存流

    imgBugPic.Picture.Graphic.SaveToStream(PicStream);

    TBlobField(FieldByName('BUGPic')).LoadFromStream(PicStream);

    PicStream.Free;

  end; 



2、从数据库中读取图片并显示

var

  PicStream: TMemoryStream; 

 if not FieldByName('BUGPic').IsNull then

      begin

        try

          PicStream := TMemoryStream.Create;

          TBlobField(FieldByName('BUGPic')).SaveToStream(PicStream);

          PicStream.Position := 0;

          imgBugPic.Picture.Bitmap.LoadFromStream(PicStream);

          PicStream.Free;

        except

          ShowMessage('对不起，图片有问题.');

        end;

      end;

 5、动态创建窗体

//第一种方式

procedure TForm1.btn1Click(Sender: TObject);

begin

With TForm2.Create(Application) do

Try

   ShowModal;

finally

   free;

end;

end;

 

//第二种方式

procedure TForm1.btn2Click(Sender: TObject);

begin

  if not assigned(Form2) then

  begin

    Form2:=TForm2.Create(nil);

    Form2.Show;

  end

end;

 

//第二种方式创建的的窗体需要在FORM2里释放资源

procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);

begin

   Form2:=nil;           //Form对象指向空地址

  Action := cafree;     //Form关闭后释放占用的内存

end;

6、错误 抛出异常

try

     ....(需要执行的代码)

except

  on e:exception do

     application.MessageBox(pchar(e.Message), '错误提示', 0);

end;

7、本月的第一和最后一天

USER ：DateUtils

procedure TForm1.btn1Click(Sender: TObject);

begin

     mmo1.Lines.Add(FormatDateTime('yyyy-mm-dd',StartOfTheMonth(Now)));

     mmo1.Lines.Add(FormatDateTime('yyyy-mm-dd',EndOfTheMonth(Now)));

   //mmo1.Lines.Add(DateTimeToStr(StartOfTheMonth(Now)));

   //mmo1.Lines.Add(DateTimeToStr(EndOfTheMonth(Now)));

end;

8、判断文件夹，没有创建

procedure TForm1.Button1Click(Sender: TObject);

var

Pach:string;

begin

Pach:='E:\123\223';                //定义目录地址

if not DirectoryExists(pach) then  //查找文件夹是否存在

  begin

  //建立文件夹(ForceDirectories可建立多级目录，创建单级目录用：CreateDirectory)

  ForceDirectories(Pach);

  end

else

  begin

  showmessage('目录已经存在');

  end;

end;

9、对Edit 循环赋值

var

  i:Integer;

  control:TComponent;

begin

  for i := 0 to 99 do

  begin

    control := FindComponent('Edit'+IntToStr(i));

    if control <> nil then

    begin

      TEdit(control).Text := IntToStr(i);

    end;

  end;

end;

10、画曲线

TeeChart 动态建曲线



var

  i:Integer;

  Series:array of TFastLineSeries;    //这里最好写在全局变量中

begin

  SetLength(Series,MyTHead.Count);

  Chart1.SeriesList.Clear;

  for i:= 0 to MyTHead.Count-1 do  //MyTHead是一个Tstringlist，根据MyTHead来动态创建曲线的数量

  begin

    Series[i]:=TFastLineSeries.Create(nil);

    Series[i].ParentChart:= Chart1; //在名为CHART1的组件上建曲线

    Series[i].Title:= MyTHead[i];

  end;

end;

 11、释放判断

XML := TNativeXml.Create(nil);



if assigned(XML)then

begin

  FreeAndNil(XML);

end;

12、锁定控件 CDS内存表 XML赋值

 with ClientDataSet1 do

    begin

      //EmptyDataSet;

      //Close;

      if FieldDefs.Count<=0 then

      begin

        FieldDefs.Clear;

        FieldDefs.Add('id',ftInteger,0);

        FieldDefs.Add('cname',ftString,100);

        FieldDefs.Add('contact',ftString,100);

        FieldDefs.Add('phone',ftString,100);

        FieldDefs.Add('addr',ftString,100);

        FieldDefs.Add('remark',ftString,100);

        //IndexDefs.Add('PK', 'id', [ixPrimary, ixUnique]);

        CreateDataSet;

      end;

      DisableControls;



     // XML.Clear;

      if not assigned(XML) then

      XML := TNativeXml.CreateName('companies');



      H := TAuthHeader.Create;

      H.UserName := '555' ; //这里只是举个例子

      H.PassWord := '555';

      Headers := WebServer as ISOAPHeaders;

      Headers.Send(H);



      retStr :=WebServer.findCompany ;

      XML.ReadFromString(retStr);

      XML.XmlFormat := xfReadable;

      //XML.SaveToFile('D:\com');



     // showmessage(IntToStr(list.Count));

      if not assigned(list) then list:=TList.Create

      else list.Clear;





      XML.Root.NodesByName('company', list);

      //showmessage('2');

      // ClientDataSet1.r

      MergeChangeLog;

      EmptyDataSet;

      listcount := list.Count;

      for i := 0 to listcount - 1 do

      begin

         node := list[i];

         if  node.ReadInteger('id')>0 then

         begin

            Append;

            FieldByName('id').AsInteger := node.ReadInteger('id');

            FieldByName('cname').AsString := node.ReadString('cname');

            FieldByName('addr').AsString := node.ReadString('addr');

            FieldByName('contact').AsString := node.ReadString('contact');

            FieldByName('phone').AsString := node.ReadString('phone');

            FieldByName('remark').AsString := node.ReadString('remark');

            Post;

         end;

         //DisPose(list[i]);

      end;

       EnableControls;

       Open;



    end;

 13、窗体拖动

procedure TMain_Frm.imgbdMouseMove(Sender: TObject; Shift: TShiftState; X,

  Y: Integer);

begin

    if (ssleft in shift) then

  begin

    releasecapture;

    perform(wm_syscommand, $f012, 0);

  end;

end;

 14、删除提示

if Application.MessageBox('删除不能恢复，确认删除吗？', '删除提示', MB_OKCANCEL + MB_ICONQUESTION)=mrOk then

begin

　　ShowMessage('你选择的OK！');

end;

 15、生成GUID guid

function GetGUID: string;

var

  Guid: TGUID;

begin

  CreateGUID(Guid);

  Result := GUIDToString(Guid);

end;

 16、检测电话号码

function TMain_frm.IsMobileNumber(num: string): boolean;

begin

  Result := False;

  if length(trim(Num)) <> 11 then

    Exit;

  if ((copy(num, 1, 2) <> '13') and (copy(num, 1, 2) <> '15')) and (copy(num, 1, 2) <> '18') and (copy(num, 1, 2) <> '14') and (copy(num, 1, 2) <> '17'))

)

)

then Exit; try StrToInt(copy(num, 3, 9)); Result := True; except end; end;

 17、改变DBGrid显示的内容

procedure TAppInterface_frm.dbgrd1DrawColumnCell(Sender: TObject;   const Rect: TRect; DataCol: Integer; Column: TColumn; State: TGridDrawState);

var

  str:string;

begin

  if (Column.Field <>nil) and (Column.FieldName = 'isencrypt') then

  begin

    if Column.Field.IsNull then exit;

    case integer(Column.Field.value)  of

       0:str:='公开';

       1:str:='传值';

       2:str:='Header';

    end;

    (Sender as TDBGrid).Canvas.TextRect(Rect,Rect.Left,Rect.Top,str);

  end;



end;

procedure TMaindlg.ADOQueryDisplayIsUsedGetText(Sender: TField; var Text: String; DisplayText: Boolean);

beginif  ADOQueryDisplay.FieldByName('Sex').AsString='0' then

          text:='女'

      else

          text:='男';

end;

DrawDataCell(ARect, DrawColumn.Field, AState);//是单元格 Dbgrid中填充数据时触发该事件
DrawColumnCell(ARect, ACol, DrawColumn, AState);//是列 Dbgrid生成每一列的时候触发该事件

18、Label自动换行 先将Autosize=false; 再设WordWrap=true;

19、ListBox基本使用方法：

一）添加

ListBox1.Add(EditBox1.Text);//添加到末尾



Items.Append('Append');//同Add



ListBox1.insert(0，EditBox1.Text);//添加到开头





//TcxImageList 参数 序号 内容 图标序号

lbxAppSupply.InsertItem(i,node.ReadString('mname')+' '+node.ReadString('name'),Random(2));

//对应的values值

lbxAppSupply.Values[i] := node.ReadString('id');



imglist1.Items[imglist1.ItemIndex];//内容

imglist1.Values[imglist1.ItemIndex];//值



//支持多选

for I := 0 to imglist1.Count - 1 do

  begin

    if imglist1.Selected[I] then

    begin

      mmo1.Text := mmo1.Text+'Selected[i]:'+imglist1.Items[i]+#13#10;

      mmo1.Text := mmo1.Text+'Values[i]:'+imglist1.Values[i]+#13#10;

    end;   

  end;  





二）删除



ListBox1.DeleteSelected;//删除选择项 包括多选



imglist1.Items.Delete(imglist1.ItemIndex);//删除选择项



三）选定



//TcxImageList 

imglist1.Selected[imglist1.Items.IndexOf('学生管理系统')]:= True;



ShowMessage(imglist1.Items[imglist1.ItemIndex]);







List为单选的取值



1）ItemIndex：为选中的list序列号从0开始，没有选时为-1



2）imglist1.Items[imglist1.ItemIndex]：为当前选中的内容



3）Items.Strings[imglist1.ItemIndex]=Items[imglist1.ItemIndex]



4）GetCount为当前记录 因为从0开始，所以可以作为插入序号