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Start an update batch.
Source position: classesh.inc line 554
public procedure TCollection.BeginUpdate; virtual;  | 
BeginUpdate is called at the beginning of a batch update. It raises the update count with 1.
Call BeginUpdate at the beginning of a series of operations that will change the state of the collection. This will avoid the call to TCollection.Update for each operation. At the end of the operations, a corresponding call to EndUpdate must be made. It is best to do this in the context of a Try ... finally block:
With MyCollection Do try BeginUpdate; // Some Lengthy operations finally EndUpdate; end;
This insures that the number of calls to BeginUpdate always matches the number of calls to TCollection.EndUpdate, even in case of an exception.
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Ends an update batch.  | 
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TCollection.Changed  | 
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Procedure called if an item is added to or removed from the collection.  | 
TCollection.Update  | 
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Handler called when an item in the collection has changed.  |