Ndef Class
Definition
Important
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Provides access to NDEF content and operations on a Tag
.
[Android.Runtime.Register("android/nfc/tech/Ndef", DoNotGenerateAcw=true)]
public sealed class Ndef : Android.Nfc.Tech.BasicTagTechnology, IDisposable, Java.Interop.IJavaPeerable
[<Android.Runtime.Register("android/nfc/tech/Ndef", DoNotGenerateAcw=true)>]
type Ndef = class
inherit BasicTagTechnology
interface ITagTechnology
interface ICloseable
interface IJavaObject
interface IDisposable
interface IJavaPeerable
- Inheritance
- Attributes
- Implements
Remarks
Provides access to NDEF content and operations on a Tag
.
Acquire a Ndef
object using #get
.
NDEF is an NFC Forum data format. The data formats are implemented in android.nfc.NdefMessage
and android.nfc.NdefRecord
. This class provides methods to retrieve and modify the android.nfc.NdefMessage
on a tag.
There are currently four NFC Forum standardized tag types that can be formatted to contain NDEF data. <ul> <li>NFC Forum Type 1 Tag (#NFC_FORUM_TYPE_1
), such as the Innovision Topaz <li>NFC Forum Type 2 Tag (#NFC_FORUM_TYPE_2
), such as the NXP MIFARE Ultralight <li>NFC Forum Type 3 Tag (#NFC_FORUM_TYPE_3
), such as Sony Felica <li>NFC Forum Type 4 Tag (#NFC_FORUM_TYPE_4
), such as NXP MIFARE Desfire </ul> It is mandatory for all Android devices with NFC to correctly enumerate Ndef
on NFC Forum Tag Types 1-4, and implement all NDEF operations as defined in this class.
Some vendors have their own well defined specifications for storing NDEF data on tags that do not fall into the above categories. Android devices with NFC should enumerate and implement Ndef
under these vendor specifications where possible, but it is not mandatory. #getType
returns a String describing this specification, for example #MIFARE_CLASSIC
is com.nxp.ndef.mifareclassic
.
Android devices that support MIFARE Classic must also correctly implement Ndef
on MIFARE Classic tags formatted to NDEF.
For guaranteed compatibility across all Android devices with NFC, it is recommended to use NFC Forum Types 1-4 in new deployments of NFC tags with NDEF payload. Vendor NDEF formats will not work on all Android devices.
<p class="note"><strong>Note:</strong> Methods that perform I/O operations require the android.Manifest.permission#NFC
permission.
Java documentation for android.nfc.tech.Ndef
.
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.
Fields
MifareClassic |
NDEF on MIFARE Classic |
NfcForumType1 |
NFC Forum Tag Type 1 |
NfcForumType2 |
NFC Forum Tag Type 2 |
NfcForumType3 |
NFC Forum Tag Type 3 |
NfcForumType4 |
NFC Forum Tag Type 4 |
Properties
CachedNdefMessage |
Get the |
Class |
Returns the runtime class of this |
Handle |
The handle to the underlying Android instance. (Inherited from Object) |
IsConnected |
Helper to indicate if I/O operations should be possible. |
IsWritable |
Determine if the tag is writable. |
JniIdentityHashCode | (Inherited from Object) |
JniPeerMembers | |
MaxSize |
Get the maximum NDEF message size in bytes. |
NdefMessage |
Read the current |
PeerReference | (Inherited from Object) |
Tag |
Get the Tag object backing this ITagTechnology object. |
ThresholdClass | (Inherited from BasicTagTechnology) |
ThresholdType | (Inherited from BasicTagTechnology) |
Type |
Get the NDEF tag type. |
Methods
CanMakeReadOnly() |
Indicates whether a tag can be made read-only with |
Clone() |
Creates and returns a copy of this object. (Inherited from Object) |
Close() |
Disable I/O operations to the tag from this ITagTechnology object, and release resources. |
Connect() |
Enable I/O operations to the tag from this ITagTechnology object. |
Dispose() | (Inherited from Object) |
Dispose(Boolean) | (Inherited from Object) |
Equals(Object) |
Indicates whether some other object is "equal to" this one. (Inherited from Object) |
Get(Tag) |
Get an instance of |
GetHashCode() |
Returns a hash code value for the object. (Inherited from Object) |
JavaFinalize() |
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Object) |
MakeReadOnly() |
Make a tag read-only. |
MakeReadOnlyAsync() | |
Notify() |
Wakes up a single thread that is waiting on this object's monitor. (Inherited from Object) |
NotifyAll() |
Wakes up all threads that are waiting on this object's monitor. (Inherited from Object) |
SetHandle(IntPtr, JniHandleOwnership) |
Sets the Handle property. (Inherited from Object) |
ToArray<T>() | (Inherited from Object) |
ToString() |
Returns a string representation of the object. (Inherited from Object) |
UnregisterFromRuntime() | (Inherited from Object) |
Wait() |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>. (Inherited from Object) |
Wait(Int64, Int32) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
Wait(Int64) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
WriteNdefMessage(NdefMessage) |
Overwrite the |
WriteNdefMessageAsync(NdefMessage) |
Explicit Interface Implementations
IJavaPeerable.Disposed() | (Inherited from Object) |
IJavaPeerable.DisposeUnlessReferenced() | (Inherited from Object) |
IJavaPeerable.Finalized() | (Inherited from Object) |
IJavaPeerable.JniManagedPeerState | (Inherited from Object) |
IJavaPeerable.SetJniIdentityHashCode(Int32) | (Inherited from Object) |
IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates) | (Inherited from Object) |
IJavaPeerable.SetPeerReference(JniObjectReference) | (Inherited from Object) |
Extension Methods
ConnectAsync(ITagTechnology) | |
JavaCast<TResult>(IJavaObject) |
Performs an Android runtime-checked type conversion. |
JavaCast<TResult>(IJavaObject) | |
GetJniTypeName(IJavaPeerable) |