Public Shared Function ForEach(Of TSource, TLocal) ( _
	source As Partitioner(Of TSource), _
	parallelOptions As ParallelOptions, _
	localInit As Func(Of TLocal), _
	body As Func(Of TSource, ParallelLoopState, TLocal, TLocal), _
	localFinally As Action(Of TLocal) _
) As ParallelLoopResult

public static ParallelLoopResult ForEach<TSource, TLocal>(
	Partitioner<TSource> source,
	ParallelOptions parallelOptions,
	Func<TLocal> localInit,
	Func<TSource, ParallelLoopState, TLocal, TLocal> body,
	Action<TLocal> localFinally
)

Type Parameters

Return Value

The Partitioner is used to retrieve the elements to be processed, in place of the original data source. If the current element's index is desired, the source must be an OrderablePartitioner.

The body delegate is invoked once for each element in the source Partitioner. It is provided with the following parameters: the current element, a ParallelLoopState instance that may be used to break out of the loop prematurely, and some local state that may be shared amongst iterations that execute on the same thread.

The localInit delegate is invoked once for each thread that participates in the loop's execution and returns the initial local state for each of those threads. These initial states are passed to the first body invocations on each thread. Then, every subsequent body invocation returns a possibly modified state value that is passed to the next body invocation. Finally, the last body invocation on each thread returns a state value that is passed to the localFinally delegate. The localFinally delegate is invoked once per thread to perform a final action on each thread's local state.