Method OnErrorResumeNext

OnErrorResumeNext<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

Creates a sequence that concatenates both given sequences, regardless of whether an error occurs.

Declaration

public static IEnumerable<TSource> OnErrorResumeNext<TSource>(this IEnumerable<TSource> first, IEnumerable<TSource> second)

Parameters

Type	Name	Description
IEnumerable<TSource>	first	First sequence.
IEnumerable<TSource>	second	Second sequence.

Returns

Type	Description
IEnumerable<TSource>	Sequence concatenating the elements of both sequences, ignoring errors.

Type Parameters

Name	Description
TSource	Source sequence element type.

Remarks

first is enumerated until either the sequence completes or an error occurs during enumeration. After either of these events, second is then enumerated in the same way.

This operator uses deferred execution and streams its results.

Examples

The following code example demonstrates how to concatenate multiple sequences, regardless of any errors that may occur, using OnErrorResumeNext.

// this sequence will throw an exception on the 6th element
var sequence = Enumerable.Range(1, 5)
    .Concat(SuperEnumerable.Throw<int>(new InvalidOperationException()));

// Skip over the error and enumerate the second sequence
var result = sequence
    .OnErrorResumeNext(
        Enumerable.Range(1, 5));

Console.WriteLine(
    "[" + 
    string.Join(", ", result) +
    "]");

// This code produces the following output:
// [1, 2, 3, 4, 5, 1, 2, 3, 4, 5]

Exceptions

Type	Condition
ArgumentNullException	first or second is null.

OnErrorResumeNext<TSource>(params IEnumerable<TSource>[])

Creates a sequence that concatenates the given sequences, regardless of whether an error occurs in any of the sequences.

Declaration

public static IEnumerable<TSource> OnErrorResumeNext<TSource>(params IEnumerable<TSource>[] sources)

Parameters

Type	Name	Description
IEnumerable<TSource>[]	sources	Source sequences.

Returns

Type	Description
IEnumerable<TSource>	Sequence concatenating the elements of the given sequences, ignoring errors.

Type Parameters

Name	Description
TSource	Source sequence element type.

Remarks

Each sequence of sources is enumerated until either the sequence completes or an error occurs during enumeration. The returned sequence completes when all sub-sequences have been enumerated in this manner.

This operator uses deferred execution and streams its results.

Examples

The following code example demonstrates how to concatenate multiple sequences, regardless of any errors that may occur, using OnErrorResumeNext.

// this sequence will throw an exception on the 6th element
var sequence = Enumerable.Range(1, 5)
    .Concat(SuperEnumerable.Throw<int>(new InvalidOperationException()));

// Skip over the error and enumerate the second sequence
var result = SuperEnumerable
    .OnErrorResumeNext(
        sequence,
        Enumerable.Range(1, 5));

Console.WriteLine(
    "[" + 
    string.Join(", ", result) +
    "]");

// This code produces the following output:
// [1, 2, 3, 4, 5, 1, 2, 3, 4, 5]

Exceptions

Type	Condition
ArgumentNullException	sources is null.

OnErrorResumeNext<TSource>(IEnumerable<IEnumerable<TSource>>)

Creates a sequence that concatenates the given sequences, regardless of whether an error occurs in any of the sequences.

Declaration

public static IEnumerable<TSource> OnErrorResumeNext<TSource>(this IEnumerable<IEnumerable<TSource>> sources)

Parameters

Type	Name	Description
IEnumerable<IEnumerable<TSource>>	sources	Source sequences.

Returns

Type	Description
IEnumerable<TSource>	Sequence concatenating the elements of the given sequences, ignoring errors.

Type Parameters

Name	Description
TSource	Source sequence element type.

Remarks

Each sequence of sources is enumerated until either the sequence completes or an error occurs during enumeration. The returned sequence completes when all sub-sequences have been enumerated in this manner.

This operator uses deferred execution and streams its results.

Examples

The following code example demonstrates how to concatenate multiple sequences, regardless of any errors that may occur, using OnErrorResumeNext.

// this sequence will throw an exception on the 6th element
var sequence = Enumerable.Range(1, 5)
    .Concat(SuperEnumerable.Throw<int>(new InvalidOperationException()));

// Skip over the error and enumerate the second sequence
var result = new[] { sequence, Enumerable.Range(1, 5), }
    .OnErrorResumeNext();

Console.WriteLine(
    "[" + 
    string.Join(", ", result) +
    "]");

// This code produces the following output:
// [1, 2, 3, 4, 5, 1, 2, 3, 4, 5]

Exceptions

Type	Condition
ArgumentNullException	sources is null.