Android Guides | Samples

Android.Util.SparseLongArray Class

SparseLongArrays map integers to longs.

See Also: SparseLongArray

Syntax

[Android.Runtime.Register("android/util/SparseLongArray", DoNotGenerateAcw=true)]
public class SparseLongArray : Object, ICloneable, IDisposable

Remarks

SparseLongArrays map integers to longs. Unlike a normal array of longs, there can be gaps in the indices. It is intended to be more memory efficient than using a HashMap to map Integers to Longs, both because it avoids auto-boxing keys and values and its data structure doesn't rely on an extra entry object for each mapping.

Note that this container keeps its mappings in an array data structure, using a binary search to find keys. The implementation is not intended to be appropriate for data structures that may contain large numbers of items. It is generally slower than a traditional HashMap, since lookups require a binary search and adds and removes require inserting and deleting entries in the array. For containers holding up to hundreds of items, the performance difference is not significant, less than 50%.

It is possible to iterate over the items in this container using SparseLongArray.KeyAt(Int32) and SparseLongArray.ValueAt(Int32). Iterating over the keys using keyAt(int) with ascending values of the index will return the keys in ascending order, or the values corresponding to the keys in ascending order in the case of valueAt(int).

[Android Documentation]

Requirements

Namespace: Android.Util
Assembly: Mono.Android (in Mono.Android.dll)
Assembly Versions: 0.0.0.0
Since: Added in API level 18

The members of Android.Util.SparseLongArray are listed below.

See Also: Object

Public Constructors

Creates a new SparseLongArray containing no mappings.
Creates a new SparseLongArray containing no mappings that will not require any additional memory allocation to store the specified number of mappings.

Protected Constructors

A constructor used when creating managed representations of JNI objects; called by the runtime.

Protected Properties

[read-only]
override
ThresholdClassIntPtr. This API supports the Mono for Android infrastructure and is not intended to be used directly from your code.
[read-only]
override
ThresholdTypeType. This API supports the Mono for Android infrastructure and is not intended to be used directly from your code.

Public Methods

Append(Int32, Int64)
Puts a key/value pair into the array, optimizing for the case where the key is greater than all existing keys in the array.
Clear()
Removes all key-value mappings from this SparseIntArray.
Clone() : SparseLongArray
Creates and returns a copy of this Object.
Delete(Int32)
Removes the mapping from the specified key, if there was any.
Get(Int32) : Int64
Gets the long mapped from the specified key, or 0 if no such mapping has been made.
Get(Int32, Int64) : Int64
Gets the long mapped from the specified key, or the specified value if no such mapping has been made.
IndexOfKey(Int32) : Int32
Returns the index for which SparseLongArray.KeyAt(Int32) would return the specified key, or a negative number if the specified key is not mapped.
IndexOfValue(Int64) : Int32
Returns an index for which SparseLongArray.ValueAt(Int32) would return the specified key, or a negative number if no keys map to the specified value.
KeyAt(Int32) : Int32
Given an index in the range 0...size()-1, returns the key from the indexth key-value mapping that this SparseLongArray stores.
Put(Int32, Int64)
Adds a mapping from the specified key to the specified value, replacing the previous mapping from the specified key if there was one.
RemoveAt(Int32)
Removes the mapping at the given index.
Size() : Int32
Returns the number of key-value mappings that this SparseIntArray currently stores.
ValueAt(Int32) : Int64
Given an index in the range 0...size()-1, returns the value from the indexth key-value mapping that this SparseLongArray stores.