Applying or Canceling a Range
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When you call SetRangeStart or EditRangeStart to specify the start of a range, or SetRangeEnd or EditRangeEnd to specify the end of a range, the dataset enters the dsSetKey state. It stays in that state until you apply or cancel the range.
Applying a range
When you specify a range, the boundary conditions you define are not put into effect until you apply the range. To make a range take effect, call the ApplyRange method, that immediately restricts a user's view of and access to data in the specified subset of the dataset.
Canceling a range
The CancelRange method ends application of a range and restores access to the full dataset. Even though canceling a range restores access to all records in the dataset, the boundary conditions for that range are still available so that you can reapply the range at a later time. Range boundaries are preserved until you provide new range boundaries or modify the existing boundaries. For example, the following code is valid:
MyTable.CancelRange; // … // Later on, use the same range again. No need to call SetRangeStart, etc. MyTable.ApplyRange;
MyTable->CancelRange(); // … // Later on, use the same range again. No need to call SetRangeStart, etc. MyTable->ApplyRange();