ImageSource

java.lang.Object
- ohos.media.image.ImageSource

```
public class ImageSource
extends Object
```
Describes image data sources used to share source data in a series of operations, such as image decoding.
Applications can use this class to decode image.
Create an ImageSource by calling create. Obtain basic image information by calling getImageInfo. Decode images by calling createPixelMap.

从以下版本开始:

1

SystemCapability

SystemCapability.Multimedia#IMAGE

嵌套类概要

嵌套类
限定符和类型	类	说明
`static interface`	`ImageSource.DecodeEventListener`	Listens for the events occurred during image decoding.
`static class`	`ImageSource.DecodingOptions`	Provides image decoding options.
`static class`	`ImageSource.IncrementalSourceOptions`	Describes options of the incremental data source.
`static class`	`ImageSource.SourceInfo`	Describes image source information, including the image quantity and file format.
`static class`	`ImageSource.SourceOptions`	Describes image data source options, including the image format represented as `image/png`, for example.
`static class`	`ImageSource.UpdateMode`	Describes the update mode of the image data source.

方法概要

所有方法静态方法实例方法具体方法
限定符和类型	方法	说明
`static ImageSource`	`create(byte[] data, int offset, int length, ImageSource.SourceOptions opts)`	Creates an `ImageSource` based on a byte array with specified offset and length.
`static ImageSource`	`create(byte[] data, ImageSource.SourceOptions opts)`	Creates an `ImageSource` based on a byte array.
`static ImageSource`	`create(FileDescriptor fd, ImageSource.SourceOptions opts)`	Creates an `ImageSource` based on a file descriptor.
`static ImageSource`	`create(File file, ImageSource.SourceOptions opts)`	Creates an `ImageSource` based on a `File` object.
`static ImageSource`	`create(InputStream is, ImageSource.SourceOptions opts)`	Creates an `ImageSource` based on an input stream.
`static ImageSource`	`create(String pathName, ImageSource.SourceOptions opts)`	Creates an `ImageSource` based on an image file path.
`static ImageSource`	`create(ByteBuffer data, ImageSource.SourceOptions opts)`	Creates an `ImageSource` based on a `ByteBuffer` and source options.
`static ImageSource`	`create(Callable<RawFileDescriptor> callable, ImageSource.SourceOptions opts)`	Creates an `ImageSource` based on a `RawFileDescriptor` that is returned by a `Callable` object.
`static ImageSource`	`createIncrementalSource(ImageSource.IncrementalSourceOptions opts)`	Creates an incremental data source based on an `IncrementalSourceOptions` object.
`static ImageSource`	`createIncrementalSource(ImageSource.SourceOptions opts)`	Creates an incremental data source based on a `SourceOptions` object.
`PixelMap`	`createPixelmap(int index, ImageSource.DecodingOptions opts)`	Decodes source image data based on a specified index location in the `ImageSource` and creates a pixel map.
`PixelMap`	`createPixelmap(ImageSource.DecodingOptions opts)`	Decodes source image data and creates a pixel map.
`PixelMap`	`createThumbnailPixelmap(ImageSource.DecodingOptions opts, boolean allowFromImage)`	Decodes thumbnail data contained in the `ImageSource` instance to generate a thumbnail and creates a thumbnail pixel map.
`protected void`	`finalize()`	Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`ImageInfo`	`getImageInfo()`	Obtains basic image information.
`ImageInfo`	`getImageInfo(int index)`	Obtains basic information about the image at a specified index.
`int`	`getImagePropertyInt(int index, String key, int defaultValue)`	Obtains the integer value of a specified property key for an image at the given index in the `ImageSource`.
`int`	`getImagePropertyInt(String key, int defaultValue)`	Obtains the integer value of a specified image property key.
`String`	`getImagePropertyString(String key)`	Obtains the string value of a specified image property key.
`byte[]`	`getImageThumbnailBytes()`	Obtains raw data of the thumbnail from the `ImageSource` instance.
`byte[]`	`getInnerJpegThumbnail()`	Obtains the byte data of the JPEG thumbnail stored in the Exif information about this JPEG `ImageSource` instance.
`long[]`	`getInnerThumbnailScope()`	Obtains the start position and data length of the thumbnail data saved in the Exif information about this JPEG `ImageSource` instance.
`ImageSource.SourceInfo`	`getSourceInfo()`	Obtains image source information.
`static HashSet<String>`	`getSupportedFormats()`	Obtains supported image formats for decoding, which are represented by MIME type strings.
`int`	`getThumbnailFormat()`	Obtains the format of the thumbnail from the `ImageSource` instance.
`ImageInfo`	`getThumbnailInfo()`	Obtains basic information (such as the size) about the thumbnail from the `ImageSource` instance.
`boolean`	`isReleased()`	Used to determine if the native resources of the Image Source has been released.
`void`	`release()`	Releases native resources associated with an object.
`void`	`setDecodeEventListener(ImageSource.DecodeEventListener listener)`	Sets a listener for observing decoding events.
`void`	`setMemoryUsagePreference(MemoryUsagePreference preference)`	Sets memory use preference.
`boolean`	`updateData(byte[] data, boolean isFinal)`	Updates incremental data to an image data source using a byte array.
`boolean`	`updateData(byte[] data, int offset, int length, boolean isFinal)`	Updates incremental data to an image data source using a byte array with specified offset and length.

从类继承的方法 java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 方法详细资料
  - getSupportedFormats
```
public static HashSet<String> getSupportedFormats()
```
    Obtains supported image formats for decoding, which are represented by MIME type strings.
    
    返回:
    
    Returns the supported formats represented by MIME type strings.
    
    从以下版本开始:
    
    1
  - setDecodeEventListener
```
public void setDecodeEventListener(ImageSource.DecodeEventListener listener)
```
    Sets a listener for observing decoding events.
    
    参数:
    
    listener - Indicates the listener to set.
    
    从以下版本开始:
    
    4
  - setMemoryUsagePreference
```
public void setMemoryUsagePreference(MemoryUsagePreference preference)
```
    Sets memory use preference.
    
    参数:
    
    preference - Indicates the preference to set, which is defined in MemoryUsagePreference.
    
    从以下版本开始:
    
    4
  - create
```
public static ImageSource create(InputStream is,
                                 ImageSource.SourceOptions opts)
```
    Creates an ImageSource based on an input stream.
    This method takes an InputStream instance as the source where the image data derives from. The ImageSource instance to create cannot be used to obtain Exif information.
    
    参数:
    
    is - Indicates an input stream of the image data source.
    
    opts - Indicates data source options.
    
    返回:
    
    Returns the ImageSource object if created; returns null if an exception occurs.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - create
```
public static ImageSource create(byte[] data,
                                 ImageSource.SourceOptions opts)
```
    Creates an ImageSource based on a byte array.
    
    参数:
    
    data - Indicates the byte array containing the source data.
    
    opts - Indicates data source options.
    
    返回:
    
    Returns the ImageSource object if created; returns null if an exception occurs.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - create
```
public static ImageSource create(ByteBuffer data,
                                 ImageSource.SourceOptions opts)
```
    Creates an ImageSource based on a ByteBuffer and source options.
    
    参数:
    
    data - Indicates the ByteBuffer that contains the image source data.
    
    opts - Indicates the source options.
    
    返回:
    
    Returns the ImageSource if the creation is successful; returns null otherwise.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if an input parameter is invalid.
    
    从以下版本开始:
    
    4
  - create
```
public static ImageSource create(Callable<RawFileDescriptor> callable,
                                 ImageSource.SourceOptions opts)
```
    Creates an ImageSource based on a RawFileDescriptor that is returned by a Callable object.
    
    参数:
    
    callable - Indicates the object that implements the Callable interface.
    
    opts - Indicates the source options.
    
    返回:
    
    Returns the ImageSource if the creation is successful; returns null otherwise.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if an input parameter is invalid.
    
    从以下版本开始:
    
    4
  - create
```
public static ImageSource create(byte[] data,
                                 int offset,
                                 int length,
                                 ImageSource.SourceOptions opts)
```
    Creates an ImageSource based on a byte array with specified offset and length.
    
    参数:
    
    data - Indicates the byte array containing the source data.
    
    offset - Indicates the offset into image data for where the reading begins.
    
    length - Indicates the image data size, in bytes.
    
    opts - Indicates data source options.
    
    返回:
    
    Returns the ImageSource object if created; returns null if an exception occurs.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    IndexOutOfBoundsException - Throws this exception if the offset or length is invalid.
    
    从以下版本开始:
    
    1
  - create
```
public static ImageSource create(String pathName,
                                 ImageSource.SourceOptions opts)
```
    Creates an ImageSource based on an image file path.
    
    参数:
    
    pathName - Indicates the file path based on which the ImageSource is created.
    
    opts - Indicates data source options.
    
    返回:
    
    Returns the ImageSource object if created; returns null if an exception occurs.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - create
```
public static ImageSource create(File file,
                                 ImageSource.SourceOptions opts)
```
    Creates an ImageSource based on a File object.
    
    参数:
    
    file - Indicates a File object.
    
    opts - Indicates data source options.
    
    返回:
    
    Returns the ImageSource object if created; returns null if an exception occurs.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - create
```
public static ImageSource create(FileDescriptor fd,
                                 ImageSource.SourceOptions opts)
```
    Creates an ImageSource based on a file descriptor.
    This method takes a FileDescriptor instance as the source where the image data derives from. The ImageSource instance to create cannot be used to obtain Exif information.
    
    参数:
    
    fd - Indicates the descriptor of an image source file.
    
    opts - Indicates data source options.
    
    返回:
    
    Returns the ImageSource object if created; returns null if an exception occurs.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - createIncrementalSource
```
public static ImageSource createIncrementalSource(ImageSource.SourceOptions opts)
```
    Creates an incremental data source based on a SourceOptions object.
    This method is used with ImageSource#updateData(byte[], int, int, boolean) to update incremental data.
    
    参数:
    
    opts - Indicates data source options.
    
    返回:
    
    Returns the ImageSource object if created; returns null if an exception occurs.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - createIncrementalSource
```
public static ImageSource createIncrementalSource(ImageSource.IncrementalSourceOptions opts)
```
    Creates an incremental data source based on an IncrementalSourceOptions object.
    This method is used with ImageSource#updateData(byte[], int, int, boolean) to update incremental data.
    
    参数:
    
    opts - Indicates incremental data source options.
    
    返回:
    
    Returns the ImageSource object if created; returns null if an exception occurs.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - createPixelmap
```
public PixelMap createPixelmap(ImageSource.DecodingOptions opts)
```
    Decodes source image data and creates a pixel map.
    For a source containing multiple images, the image data of index 0 is decoded by default.
    
    参数:
    
    opts - Indicates image decoding options.
    
    返回:
    
    Returns the image if the data is decoded; returns null if an exception occurs.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - createPixelmap
```
public PixelMap createPixelmap(int index,
                               ImageSource.DecodingOptions opts)
```
    Decodes source image data based on a specified index location in the ImageSource and creates a pixel map.
    For a source containing multiple images, use an index to specify the image location.
    
    参数:
    
    index - Indicates an index specifying the image location. The index starts from 0.
    
    opts - Indicates image decoding options.
    
    返回:
    
    Returns the image if the data is decoded; returns null if an exception occurs.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - createThumbnailPixelmap
```
public PixelMap createThumbnailPixelmap(ImageSource.DecodingOptions opts,
                                        boolean allowFromImage)
```
    Decodes thumbnail data contained in the ImageSource instance to generate a thumbnail and creates a thumbnail pixel map.
    
    参数:
    
    opts - Indicates image decoding options.
    
    allowFromImage - Specifies whether to allow creation based on the original image if the ImageSource does not contain thumbnail data.
    
    返回:
    
    Returns the created PixelMap if the decoding is successful; returns null if the decoding fails.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    IllegalStateException - Throws this exception if native resources associated with this ImageSource have been released.
    
    从以下版本开始:
    
    2
  - updateData
```
public boolean updateData(byte[] data,
                          boolean isFinal)
```
    Updates incremental data to an image data source using a byte array.
    When incremental data is obtained, use this method to update source data. Input data requirements are described by UpdateMode.
    
    参数:
    
    data - Indicates the byte array inputting incremental data.
    
    isFinal - Indicates whether the data update is the last batch.
    
    返回:
    
    Returns true if the source data is updated; returns false otherwise.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - updateData
```
public boolean updateData(byte[] data,
                          int offset,
                          int length,
                          boolean isFinal)
```
    Updates incremental data to an image data source using a byte array with specified offset and length.
    When incremental data is obtained, use this method to update source data. Input data requirements are described by UpdateMode.
    
    参数:
    
    data - Indicates the byte array inputting incremental data.
    
    offset - Indicates offset into image data for where the reading starts.
    
    length - Indicates the size of the incremental data, in bytes.
    
    isFinal - Indicates whether the data is the last batch.
    
    返回:
    
    Returns true if the data is updated; returns false otherwise.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    IndexOutOfBoundsException - Throws this exception if the offset or length is invalid.
    
    从以下版本开始:
    
    1
  - getImageInfo
```
public ImageInfo getImageInfo()
```
    Obtains basic image information.
    
    返回:
    
    Returns the ImageInfo object if obtained; returns null otherwise. Note that the returned ImageInfo object contains only the ImageInfo.size of this ImageSource object. Other image information can be obtained only after image decoding.
    
    从以下版本开始:
    
    1
  - getImageInfo
```
public ImageInfo getImageInfo(int index)
```
    Obtains basic information about the image at a specified index.
    
    参数:
    
    index - Indicates the image index, which starts from 0.
    
    返回:
    
    Returns the ImageInfo object if obtained; returns null otherwise. Note that the returned ImageInfo object contains only the ImageInfo.size of this ImageSource object. Other image information can be obtained only after image decoding.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if the input parameter is invalid.
    
    从以下版本开始:
    
    1
  - getImagePropertyString
```
public final String getImagePropertyString(String key)
```
    Obtains the string value of a specified image property key.
    
    参数:
    
    key - Indicates a key defined in PropertyKey.
    
    返回:
    
    Returns the property key value if obtained; returns null if the property does not exist.
    
    抛出:
    
    IllegalStateException - Throws this exception if native resources associated with this ImageSource instance have been released.
    
    IllegalArgumentException - Throws this exception if key is null.
    
    从以下版本开始:
    
    4
  - getImagePropertyInt
```
public final int getImagePropertyInt(String key,
                                     int defaultValue)
```
    Obtains the integer value of a specified image property key.
    
    参数:
    
    key - Indicates a key defined in PropertyKey.
    
    defaultValue - Indicates the custom default value of the property key.
    
    返回:
    
    Returns the integer value if obtained; returns the custom default value if the property key does not exist or is incompatible with integers.
    
    抛出:
    
    IllegalStateException - Throws this exception if native resources associated with this ImageSource instance have been released.
    
    IllegalArgumentException - Throws this exception if key is null.
    
    从以下版本开始:
    
    4
  - getImagePropertyInt
```
public final int getImagePropertyInt(int index,
                                     String key,
                                     int defaultValue)
```
    Obtains the integer value of a specified property key for an image at the given index in the ImageSource.
    
    参数:
    
    index - Indicates an index specifying the image location. The index starts from 0.
    
    key - Indicates a key defined in PropertyKey.
    
    defaultValue - Indicates the custom default value of the property key.
    
    返回:
    
    Returns the integer value if obtained; returns the custom default value if the property key does not exist or is incompatible with integers.
    
    抛出:
    
    IllegalStateException - Throws this exception if native resources associated with this ImageSource instance have been released.
    
    IllegalArgumentException - Throws this exception if key is null.
    
    从以下版本开始:
    
    4
  - getThumbnailInfo
```
public ImageInfo getThumbnailInfo()
```
    Obtains basic information (such as the size) about the thumbnail from the ImageSource instance.
    Currently, only thumbnails in JPEG format can be identified.
    
    返回:
    
    Returns the basic information if obtained; returns null if the thumbnail is not in JPEG format.
    
    抛出:
    
    IllegalStateException - Throws this exception if native resources associated with this ImageSource instance have been released.
    
    UnsupportedOperationException - Throws this exception if the source image file does not contain a thumbnail.
    
    从以下版本开始:
    
    4
  - getInnerJpegThumbnail
```
public byte[] getInnerJpegThumbnail()
```
    Obtains the byte data of the JPEG thumbnail stored in the Exif information about this JPEG ImageSource instance.
    返回:
    
    Returns a byte array containing the thumbnail data if the Exif information of this JPEG ImageSource instance contains a thumbnail in JPEG format; returns null if the Exif information does not contain a thumbnail or the thumbnail is not a JPEG file.
    
    抛出:
    IllegalStateException - IllegalStateException Throws this exception if this ImageSource instance:
    
    Is in an unknown format.
    
    Is abnormal.
    
    Has been released.
    从以下版本开始:
    
    6
  - getInnerThumbnailScope
```
public long[] getInnerThumbnailScope()
```
    Obtains the start position and data length of the thumbnail data saved in the Exif information about this JPEG ImageSource instance.
    返回:
    
    Returns a long array containing the start position of the thumbnail data and the data length if the Exif information of this JPEG ImageSource instance has thumbnail data; returns null if there is no thumbnail data in the Exif information or the thumbnail data is discrete.
    
    抛出:
    IllegalStateException - Throws this exception if this ImageSource instance:
    
    Is in an unknown format.
    
    Is abnormal.
    
    Has been released.
    从以下版本开始:
    
    6
  - getImageThumbnailBytes
```
public byte[] getImageThumbnailBytes()
```
    Obtains raw data of the thumbnail from the ImageSource instance.
    
    返回:
    
    Returns the byte array containing the thumbnail data if the thumbnail exists.
    
    抛出:
    
    IllegalStateException - Throws this exception if native resources associated with this ImageSource instance have been released.
    
    UnsupportedOperationException - Throws this exception if the source image file does not contain a thumbnail.
    
    从以下版本开始:
    
    3
  - getThumbnailFormat
```
public int getThumbnailFormat()
```
    Obtains the format of the thumbnail from the ImageSource instance.
    Currently, only thumbnails in JPEG format can be identified.
    
    返回:
    
    Returns ImageFormat.JPEG if the thumbnail is in JPEG format; returns ImageFormat.UNKNOWN otherwise.
    
    抛出:
    
    IllegalStateException - Throws this exception if native resources associated with this ImageSource have been released.
    
    UnsupportedOperationException - Throws this exception if the source image file does not contain a thumbnail.
    
    从以下版本开始:
    
    3
  - getSourceInfo
```
public ImageSource.SourceInfo getSourceInfo()
```
    Obtains image source information.
    
    返回:
    
    Returns the image source information if obtained; returns null if an exception occurs.
    
    从以下版本开始:
    
    1
  - release
```
public void release()
```
    Releases native resources associated with an object.
    
    从以下版本开始:
    
    1
  - isReleased
```
public boolean isReleased()
```
    Used to determine if the native resources of the Image Source has been released.
    
    返回:
    
    True if the native resources of the ImageSource has been released
    
    从以下版本开始:
    
    4
  - finalize
```
protected void finalize()
                 throws Throwable
```
    从类复制的说明: Object
    
    Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the finalize method to dispose of system resources or to perform other cleanup.
    The general contract of finalize is that it is invoked if and when the Java™ virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded.
    The finalize method of class Object performs no special action; it simply returns normally. Subclasses of Object may override this definition.
    The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates.
    After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.
    The finalize method is never invoked more than once by a Java virtual machine for any given object.
    Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored.
    
    覆盖:
    
    finalize 在类中 Object
    
    抛出:
    
    Throwable - the Exception raised by this method
    
    另请参阅:
    
    WeakReference, PhantomReference

类 ImageSource

嵌套类概要

方法概要

从类继承的方法 java.lang.Object

方法详细资料

getSupportedFormats

setDecodeEventListener

setMemoryUsagePreference

create

create

create

create

create

create

create

create

createIncrementalSource

createIncrementalSource

createPixelmap

createPixelmap

createThumbnailPixelmap

updateData

updateData

getImageInfo

getImageInfo

getImagePropertyString

getImagePropertyInt

getImagePropertyInt

getThumbnailInfo

getInnerJpegThumbnail

getInnerThumbnailScope

getImageThumbnailBytes

getThumbnailFormat

getSourceInfo

release

isReleased

finalize