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twquac
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几天无人问律的问题，想问问各位高手，这题难吗？还是各位看到分数少？如果是因为分少的话，我可以开另外一个贴子送分，只求各位说句话。(在线等待) ( 积分: 40 )<br />function Createdxdbgdcol(aApp:TApplication;DllScr:TScreen;Mydataset:TDataSet;
Mydxdbgd:TdxDBGrid):boolean;stdcall;
var
i,n:integer;
Newbands:TdxTreeListBand;
begin
CoInitialize(Nil);
Application:=aApp;
Screen:=DllScr;
for i:=0 to Mydxdbgd.ColumnCount-1 do
Mydxdbgd.Columns[0].Destroy ;
//建立两个band,一个为显示锁定列,另一个为显示非锁定列
for i:=0 to Mydxdbgd.Bands.Count-1 do
Mydxdbgd.Bands[0].Destroy;
Newbands:=Mydxdbgd.Bands.Add;
Newbands.MinWidth :=0;
Newbands.Width :=0;
Newbands.Fixed :=bfLeft;
Newbands:=Mydxdbgd.Bands.Add;
n:=0;
for i:=0 to Mydataset.FieldCount-1 do
begin
if MydataSet.Fields.Visible =False then
Continue
else
begin
//建立列
[red]Mydxdbgd.CreateColumn(TdxDBGridColumn);[/red] //设置列
Mydxdbgd.Columns[n].BandIndex :=1;
Mydxdbgd.Columns[n].FieldName :=Mydataset.Fields.FieldName;
Mydxdbgd.Columns[n].Caption :=Mydataset.Fields.DisplayLabel ;
Inc
;
end;
end;
end;
我把创建dxdbgrid控件列的代码写入DLL中，可每次调用时一执行到Mydxdbgd.CreateColumn(TdxDBGridColumn)就出错，错误提示为：invalid class typecast,这是为什么？
Mydxdbgd:TdxDBGrid):boolean;stdcall;
var
i,n:integer;
Newbands:TdxTreeListBand;
begin
CoInitialize(Nil);
Application:=aApp;
Screen:=DllScr;
for i:=0 to Mydxdbgd.ColumnCount-1 do
Mydxdbgd.Columns[0].Destroy ;
//建立两个band,一个为显示锁定列,另一个为显示非锁定列
for i:=0 to Mydxdbgd.Bands.Count-1 do
Mydxdbgd.Bands[0].Destroy;
Newbands:=Mydxdbgd.Bands.Add;
Newbands.MinWidth :=0;
Newbands.Width :=0;
Newbands.Fixed :=bfLeft;
Newbands:=Mydxdbgd.Bands.Add;
n:=0;
for i:=0 to Mydataset.FieldCount-1 do
begin
if MydataSet.Fields.Visible =False then
Continue
else
begin
//建立列
[red]Mydxdbgd.CreateColumn(TdxDBGridColumn);[/red] //设置列
Mydxdbgd.Columns[n].BandIndex :=1;
Mydxdbgd.Columns[n].FieldName :=Mydataset.Fields.FieldName;
Mydxdbgd.Columns[n].Caption :=Mydataset.Fields.DisplayLabel ;
Inc
;end;
end;
end;
我把创建dxdbgrid控件列的代码写入DLL中，可每次调用时一执行到Mydxdbgd.CreateColumn(TdxDBGridColumn)就出错，错误提示为：invalid class typecast,这是为什么？
]