刷新dbgrid 而不失去当前行位置

http://www.delphishare.com/?/1207-1-0-1-1.html

http://delphi.about.com/od/delphitips2008/qt/dbgrid_row_pos.htm

google翻译并整理

我们有一个Delphi的数据库应用程序,上面有个DBGrid和一个数据集：
 

DBGrid是用来显示来自数据集（查询或表）的数据，根据设计,当您调用已经打开的数据集的Refresh方

法（例如使用DBNavigator的Refresh），当前行的位置将被设置为0 （第一个记录）。

这意味着，如果用户选择了DBGrid的底部某个地方的一行记录，在刷新后，当前激活的行将改为第一行:

(

如果你一直在问：“有什么办法重新查询或刷新后，让TDBGrid中的数据留在准确位置（不改变位置）？

”这里的一个答案的问题：

刷新DBGrid的数据 - 保留行的位置
这里的一个小程序控制刷新DBGrid的内容后不会失去该行的位置。

 //THackDBGrid = class(TDBGrid)
 
 //refresh datagrid data - preserve rowposition
 procedure Refresh_PreservePosition;
 var
   rowDelta: Integer;
   row: integer;
   recNo: integer;
   ds : TDataSet;
 begin
   ds :=THackDBGrid(DBGrid1).DataSource.DataSet;
 
   rowDelta := -1 +THackDBGrid(DBGrid1).Row;
   row := ds.RecNo;
 
   ds.Refresh;
 
   with ds do
   begin
    DisableControls;
    RecNo := row;
    MoveBy(-rowDelta) ;
    MoveBy(rowDelta) ;
    EnableControls;
   end;
 end;

 请注意这里使用的保护破解（THackDBGrid）来获得隐藏的（protected）Row属性！

英文原文

There's DBGrid, there's adataset and we have a data awareDelphi application :)

When DBGrid is used to display data from a dataset (query ortable), by design, after you call Refresh method on a dataset(re-open) (for example, using a DBNavigator), the current row position will be setto zero (first record).

This means that if a user has selected a row somewhere near thebottom of a DBGrid, after a Refresh, the active row will be changedto first row :(

If you have been asking "Is there any way to reopen or refresh aquery, leaving the TDBGrid data exactly where it is (withoutchanging the positions)?" Here's one answer to the problem:

Refresh DBGrid Data - Preserve Row Position

Here's a handly little procedure to refresh the content of aDBGrid without losing the row position.

 //THackDBGrid = class(TDBGrid)
 
 //refresh datagrid data - preserve row position
 procedure Refresh_PreservePosition;
 var
   rowDelta: Integer;
   row: integer;
   recNo: integer;
   ds : TDataSet;
 begin
   ds := THackDBGrid(DBGrid1).DataSource.DataSet;
 
   rowDelta := -1 + THackDBGrid(DBGrid1).Row;
   row := ds.RecNo;
 
   ds.Refresh;
 
   with ds do
   begin
     DisableControls;
     RecNo := row;
     MoveBy(-rowDelta) ;
     MoveBy(rowDelta) ;
     EnableControls;
   end;
 end;

Note the protected hack used here(THackDBGrid) to get the hidden (protected) Row property!