public          
        class
公共类

Surface

Class Overview类的概述

Handle onto a raw buffer that is being managed by the screen compositor.被屏幕合成器所管理的 原生缓冲区 的句柄。

Summary

[Expand] Inherited Constants
From interface android.os.Parcelable

[Expand] Inherited Methods
From class   java.lang.Object
From interface   android.os.Parcelable

Constants

public
        static
        final
        int      
        ROTATION_0

Added
in API
level 1

Rotation constant: 0 degree rotation (natural orientation)

Constant
Value:        
           
               
0
               
(0x00000000)

public
        static
        final
        int      
        ROTATION_180

Added
in API
level 1

Rotation constant: 180 degree rotation.

Constant
Value:        
           
               
2
               
(0x00000002)

public
        static
        final
        int      
        ROTATION_270

Added
in API
level 1

Rotation constant: 270 degree rotation.

Constant
Value:        
           
               
3
               
(0x00000003)

public
        static
        final
        int      
        ROTATION_90

Added
in API
level 1

Rotation constant: 90 degree rotation.

Constant
Value:        
           
               
1
               
(0x00000001)

Fields

public
        static
        final
        Creator<Surface>
     
        CREATOR

Added
in API
level 1

Public Constructors共有构造方法

public
        
        
        
        
             
      Surface
      (SurfaceTexture
surfaceTexture)

Added in API
level 14

从一个SurfaceTexture中创建surface。被画到surface的图像将会被SurfaceTexture可得到。SurfaceTexture可以通过updateTextImage()方法附加他们到一个开放的图形ES
texture。
Create Surface from a SurfaceTexture.

Images drawn to the Surface will be made available to the SurfaceTexture,
which can attach them to an OpenGL ES texture via updateTexImage().

Parameters

Throws

Public Methods

public
        
        
        
        
        int      
      describeContents       ()

Added in API
level 1

用这个包的
marshalled 描述方法来描述这个包内的 不同的对象。

Describe the kinds of special objects contained in this Parcelable‘s
marshalled representation.

Returns

• a bitmask indicating the set of special object types marshalled by the
  Parcelable.

public
        
        
        
        
        boolean
            isValid       ()

Added in API
level 1

如果这个对象持有一个有效的surface，则返回true

Returns true if this object holds a valid surface.

Returns

• True if it holds a physical surface, so lockCanvas() will succeed.
  Otherwise returns false.

public
        
        
        
        
        Canvas
            lockCanvas       (Rect
inOutDirty)

Added in API
level 1
   获取一个canvas，用来画东西到这个surface中。当画到一个提供的Canvas中时，这个caller必需调用unlockCanvasAndPost(Canvas)来提交新的内容到surface。

Gets a Canvas
for drawing into this surface.
After drawing into the provided Canvas,
the caller must invoke unlockCanvasAndPost(Canvas)
to post the new contents to the surface.

Parameters

Returns

• A canvas for drawing into the surface.

Throws

public
        
        
        
        
        void      
      readFromParcel       (Parcel
source)

Added in API
level 1

从这个包中读取资源

public
        
        
        
        
        void      
      release
      ()

Added in API
level 14

释放本地对服务端surface的连接指引。总是调用release()当你完成一个surface相关工作时。这会让surface无效。

Release the local reference to the server-side surface. Always call
release() when you‘re done with a Surface. This will make the surface
invalid.

public
        
        
        
        
        String
            toString       ()

Added in API
level 1
         

    返回一个字符串，包含一个精确的，人类可读懂的对于这个对象的描述。子类被鼓励去重写这个方法并且提供一个实现。这个实现需要考虑这个对象的类型和数据。默认的实现与下面的表达相等
getClass().getName()+‘@‘+Integer,toHexString(hashCode())

请看一个有效的写的方法 toString()。如果你打算实现你自己的同String方法时。

Returns a string
containing a concise, human-readable description of this object. Subclasses are
encouraged to override this method and provide an implementation that takes
into account the object‘s type and data. The default implementation is
equivalent to the following expression:

   getClass().getName()+‘@‘+Integer.toHexString(hashCode())

See Writing
a useful toString method if you intend implementing your own
toString method.

Returns

• a printable representation of this object.返回一个打印的这个对象的描述。

public
        
        
        
        
        void      
      unlockCanvas
      (Canvas
canvas)

Added in API
level 1

      This method was
deprecated       in API level
17.
    This API has been removed and is not
supported.  Do not use.

public
        
        
        
        
        void      
      unlockCanvasAndPost       (Canvas
canvas)

Added in API
level 1

Posts the new contents of the Canvas
to the surface and releases the Canvas.

Parameters

public
        
        
        
        
        void      
      writeToParcel
      (Parcel
dest, int flags)

Added in API
level 1

扁平化这个对象到一个打包中。

Flatten this object in to a Parcel.

Parameters

Protected Methods

protected
        
        
        
        
        void      
      finalize
      ()

Added in API
level 1
         

     
   调用当垃圾回收期侦测到这个实例不再可读时。虽然这个默认的实现没有做任何事情，但是这个方法可以重写到自由的资源。

Invoked when the garbage collector has detected that this instance is no
longer reachable. The default implementation does nothing, but this method can
be overridden to free resources.
 注意对象重写finalize
值得注意的它比不重写的对象是更昂贵。当这个对象不再可读时，Finalizers或许运行很长一段时间，这依赖于内存的压力，因此依赖这个方法来实现cleanup是很不好的一个注意。另外也要注意finalizers运行在一个单独的VM
wide
finalizer线程，因此在一个finalizer中进行一个堵塞性的工作是非常不好的。一个finalizer通常仅仅在一个类有一个本地的peer而且需要调用一个本地方法去销毁那个同龄的peer。即使如此，最好提供一个明确的close方法（并实现Closeable），并且坚持这个callers人为的处理这个instance。这个有时工作的很好，例如对于files，但是对于一些像BigInteger这些典型的调用代码则会处理很多临时性的问题。不幸的是，创建很多临时性的代码是最烂的代码之一，就view的
单finalizer线程而言。

Note that objects that override finalize are significantly more
expensive than objects that don‘t. Finalizers may be run a long time after the
object is no longer reachable, depending on memory pressure, so it‘s a bad idea
to rely on them for cleanup. Note also that finalizers are run on a single
VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea.
A finalizer is usually only necessary for a class that has a native peer and
needs to call a native method to destroy that peer. Even then, it‘s better to
provide an explicit close method (and implement Closeable),
and insist that callers manually dispose of instances. This works well for
something like files, but less well for something like a BigInteger
where typical calling code would have to deal with lots of temporaries.
Unfortunately, code that creates lots of temporaries is the worst kind of code
from the point of view of the single finalizer thread.
如果你必须finalizers，考虑一下至少提供你自己的ReferenceQueue并且有你自己的队列线程。

If you must use finalizers, consider at least providing your own
ReferenceQueue
and having your own thread process that queue.
不像构造方法，finalizers不是自动的链接上的。你要自己负责调用super.finalize()方法。

Unlike constructors, finalizers are not automatically chained. You are
responsible for calling super.finalize() yourself.
由finalizers抛出的未捕捉的异常，被忽略。并且不决定这个finalizer线程。看
Effective Java Item7的“Avoid finalizers”获得更多的内容。

Uncaught exceptions thrown by finalizers are ignored and do not terminate the
finalizer thread.
See Effective Java Item 7, "Avoid finalizers"
for more.

Throws

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