【搞定】function的参数设置相关问题**

chaoqiang

如下面这个函数，
function Txxx.fnReturnXXX(const PDestDs:TDataSet):string;
var lvTempDs:TDataSet;
begin
  ......
  
  lvTempDs.Last;
end;
我要使得lvTempDs的内容与PDestDs一样，但对lvTempDs的任何操作不影响到PDestDs（如 lvTempDs.Last,而PDestDs没有被Last）。
请问我要如何定义这样的函数？

lisb

function Txxx.fnReturnXXX(PDestDs:TDataSet):string;

alang

Shares the data belonging to another client dataset.

procedure CloneCursor(Source :TCustomClientDataSet; Reset: Boolean; KeepSettings: Boolean = False); virtual;


Description

Call CloneCursor to share the data belonging to another client dataset. Source indicates another client dataset whose data is to be shared.

Reset and KeepSettings determine how to set the values of the following properties and events:

Filter, Filtered, FilterOptions, and OnFilterRecord
        IndexName
        MasterSource and MasterFields
        ReadOnly
        RemoteServer and ProviderName

If Reset and KeepSettings are both False, the values of the properties listed above are all set to match the source dataset.

If Reset is True, the properties listed above are all cleared.

If Reset is False and KeepSettings is True, the properties listed above are not changed. In this case, the application must ensure that existing indexes, providers, and so on are compatible with the cloned data.

After calling CloneCursor, the data for the client dataset is the same as the data for Source. Edits performed by either client dataset are reflected in the data of both datasets.

Note:        Because cloned cursors are shared, changing properties that affect the cursor affect both datasets. For example, setting the ReadOnly property of either dataset will make both datasets read-only.

chaoqiang

alang给的CloneCursor正是我想要的，呵呵。
二楼的方法我也是试过了，不可以。我本以为有类似DotNet里头的ByVal和ByRef东西。
谢谢