ePx Studio 7.2 常用语法学习真实经典案例

1、 使用控件属性作为判断条件：

……
if RadioButton2.Checked then
begin
Statement := this.Replace( Statement,'varchar','varchar2' );
Statement := this.Replace( Statement,'int','number' );
end;
……

2、 使用控件 Items 集合数量控制循环次数，同时循环与判断相嵌套：

……
CheckCount := 0;
for I := 0 to CheckListBox1.Items.Count - 1 do
begin
if CheckListBox1.Checked[ I ] then
begin
CheckCount := CheckCount + 1;
end;
end;
if CheckCount = 0 then
begin
this.ShowMessage('没有选择任何需要导入的数据表定义，不能继续操作！ ');
Exit;
end;
……

3、 循环与判断综合嵌套应用：

……
if CanContinue then
begin
    TableList := TStringList.Create;
    ViewContent := '';
    TableWantDealed := False;
    TableIndex := 0;
    ProgressBar1.Max := Contents.length;
    ProgressBar1.Position := 0;
    for I := 0 to Contents.length - 1 do
        beginProgressBar1.Position := I + 1;
        this.ProcessMessage;
        Item := Contents.get( I );
        TableName := VarToStr( Item.get( '表名' ) );
    if TableList.IndexOf( TableName ) < 0 then
    begin
        //向系统表定义插入一行，并创建一张表
    if Length( ViewContent ) > 0 then
    begin
    //创建视图
    if TableWantDealed then
    begin
        CreateSingleView( ViewContent,LastTableName,EnTable,EnView );
    end;
    ViewContent := '';
    end;
    //创建表定义及表
    TableIndex := TableIndex + 1;
    TableWantDealed := False;
    ItemIndex := CheckListBox1.Items.IndexOf( TableName );
    if ItemIndex >= 0 then
    begin
        TableWantDealed := CheckListBox1.Checked[ ItemIndex ];
        CheckListBox1.ItemIndex := ItemIndex;
    end;
    if TableWantDealed then
    begin
        AddAndCreateSingleTable( Item,TableIndex,TableName,EnTable,EnView );
        this.PlaySoundRes( 0 );
    end;
    LastTableName := TableName;
    TableList.Add(TableName);
    end;
    EnName := Trim( VarToStr( Item.get( '代码' ) ) );
    CnName := Trim( VarToStr( Item.get( '中文名' ) ) );
    DispNm := Trim( VarToStr( Item.get( '显示用名' ) ) );
    if Length( DispNm ) = 0 then DispNm := CnName;
    if Length( DispNm ) = 0 then DispNm := EnName;
    Item.set( '显示用名',DispNm );
    //添加列定义
    if TableWantDealed then
    begin
        AddSingleColumnDefine( Item, TableName, EnTable,EnView );
    end;
    if Length(ViewContent) > 0 then ViewContent := ViewContent + ',';
    ViewContent := ViewContent + EnName + ' "' + DispNm + '"';
    end;
    if Length( ViewContent ) > 0 then
    begin
        //创建视图
    if TableWantDealed then
    begin
        CreateSingleView( ViewContent,LastTableName,EnTable,EnView );
    end;
    end;
    FreeAndNil( TableList );
end;
……

4、 For 与 While 循环嵌套应用：

……
ProgressBar1.Max:=OldStory.ListParagraphs.Count;
for I := 1 to OldStory.ListParagraphs.Count - 1 do
begin
ProgressBar1.Position:=I;
this.ProcessMessage;
Finished := False;
while not Finished do
begin
try
CRange := OldStory.ListParagraphs[I].Range;
OLevel := CRange.Paragraphs[1].OutlineLevel;
if OLevel = 6 then
begin
OPage := CRange.Information[wdActiveEndPageNumber] - 35;
CTitle := Trim(this.Replace(CRange.Text,'：（.*?） ',''));
CStart := CRange.Start;
//紧接着的下一标题
for J := I + 1 to OldStory.ListParagraphs.Count do
begin
NRange := OldStory.ListParagraphs[J].Range;
if NRange.Paragraphs[1].OutlineLevel <= 6 then Break;
end;
NStart := NRange.Start;
OldSel.SetRange(CStart,NStart);
OldSel.Copy;
<此处省略若干行次>
this.DeleteFile(SHtmlFile);this.RandomFileWrite(HtmlFile,0,HtmlContent);
//选择所有内容（下次粘贴时会覆盖）
NewSel.SetRange( 0,99999 );
end;
Finished := True;
except
Finished := False;
end;
end;
end;
……

5、 通过函数返回值作为判断条件：

……
if this.ReadIniSectionValue(ConfigFile,'初始化窗口属性','边框') = '无' then
begin
Form1.BorderStyle := bsNone;
end;
if this.ReadIniSectionValue(ConfigFile,'初始化窗口属性','最大化显示') = '是' then
begin
Form1.SetBounds(0,0,this.ScreenWorkAreaWidth,this.ScreenWorkAreaHeight);
end else
begin
<此处省略若干行次>
end;
if this.FileExists(CommandLine.ProjectRoot + '' + ProjectName + '.ico') then
begin
Form1.Icon.LoadFromFile(CommandLine.ProjectRoot + '' + ProjectName + '.ico');
end;
……

6、 涉及到 JSON 数组与 JSON 对象的循环和判断应用：

……
MenuKeys := this.ReadIniSectionKeys(ConfigFile,'菜单列表');
for I := 0 to MenuKeys.length - 1 do
begin
MKey := VarToStr(MenuKeys.get(I));
MValue := this.ReadIniSectionValue(ConfigFile,'菜单列表',MKey);
InfoItems := this.Split(MValue,'|');
if InfoItems.Count = 3 then
begin
MCaption := InfoItems.Strings[0];
MIcon := InfoItems.Strings[1];
MModule := InfoItems.Strings[2];Window.registerAMenuIcon(MKey,MCaption,MIcon,MModule);
end;
end;
……

7、 判断与异常处理语句的综合应用：

……
var MenuId,Registered,Module,AName: string;
I: Integer;
AParams,AResult: Variant;
const SWP_NOSIZE = 1;
SWP_NOMOVE = 2;
SWP_FRAMECHANGED = $20;
begin
if Identity = 'OnNavBarMenuClicked' then
begin
MenuId := VarToStr(this.ArrayRead(Params,0));
Registered := VarToStr(this.ArrayRead(Params,1));
Module := VarToStr(this.ArrayRead(Params,2));
if Pos(':',Module) = 0 then
begin
Module := CommandLine.ProjectRoot + '' + Module;
end;
Module := this.Replace(Module,'\',SlashFlag);
if this.FileExists(Module) or (RunMode='BS') then
begin
if Registered = '0' then
begin
Window.registerAModule(MenuId,VarToStr(CommandLine.ProjectRoot));
end;
Window.activeAModule(MenuId);
end else
begin
this.ShowMessage('模块' + MenuId + '不存在!');
end;
end else
if Identity = 'GetVariable' then
begin
AName := VarToStr(this.ArrayRead(Params,0));
try
AResult := Window.htmlVariable(AName);
EPX.ClearResults;
EPX.AddAResult(AResult);
exceptthis.Alert('主框架未定义 htmlVariable 方法.');
end;
end else
if Identity = 'CallHtmlFunction' then
begin
AName := VarToStr(this.ArrayRead(Params,0));
AParams := this.NewArray;
try
for I := 1 to Params.length - 1 do
begin
AParams.set(I-1,this.ArrayRead(Params,I));
end;
finally
if Length(AName) > 0 then
begin
try
AResult := Window.htmlFunction(AName,AParams);
EPX.ClearResults;
EPX.AddAResult(AResult);
except
this.Alert('主框架未定义 htmlFunction 方法.');
end;
end;
end;
end;
end;
……

8、 判断与循环在普通函数中的应用：

……
procedure GenerateProcedureDeclareContent(Struct: Variant;DLines,CLines: TStrings;C
ClassName: string);
var CStruct,CItem,PItem,CParams: Variant;
CName,PName,PType,CDeclare,CCall: string;
I,J: Integer;
begin
//生成过程声明
CStruct := Struct.get('procedures');
if not this.VarAssigned(CStruct) then Exit;
for I:= 0 to CStruct.length - 1 do
begin
CItem := CStruct.get(I);
CName := VarToStr(CItem.get('name'));
//函数名称CDeclare := 'procedure ' + CName;
if CLines.Count = 0 then
begin
CCall := ' if MethodName=''' + UpperCase(CName) + ''' then'#13#10;
end else
begin
CCall := ' else if MethodName=''' + UpperCase(CName) + ''' then'#13#10;
end;
CCall := CCall + ' ' + CClassName + '(Instance).' + CName;
CParams := CItem.get('params');
if this.VarAssigned(CParams) then
begin
if CParams.length > 0 then
begin
CDeclare := CDeclare + '(';
CCall := CCall + '(';
end;
for J := 0 to CParams.length - 1 do
begin
PItem := CParams.get(J);
PName := VarToStr(PItem.get('name'));
PType := VarToStr(PItem.get('type'));
if J > 0 then
begin
CDeclare := CDeclare + ';';
CCall := CCall + ',';
end;
CDeclare := CDeclare + PName + ':' + PType;
if Copy(PType,1,1) = 'T' then
begin
CCall := CCall + PType + '(Integer(Params[' + IntToStr(J) + ']))';
end else
begin
CCall := CCall + 'Params[' + IntToStr(J) + ']';
end;
end;
if CParams.length > 0 then
begin
CDeclare := CDeclare + ')';
CCall := CCall + ')';
end;
end;
//函数返回值类型
CDeclare := ' AddMethod(''' + CDeclare + ''',CallMethod);';DLines.Add(CDeclare);
CLines.Add(CCall);
end;
end;
……