xyz.zpayh.hdimage.util

类 ImageCache

java.lang.Object

xyz.zpayh.hdimage.util.ImageCache

public class ImageCache
extends java.lang.Object

方法概要

限定符和类型	方法和说明
static int	calculateInSampleSize(android.graphics.BitmapFactory.Options options, int reqWidth, int reqHeight) Calculate an inSampleSize for use in a BitmapFactory.Options object when decoding bitmaps using the decode* methods from BitmapFactory.
static int	getBitmapSize(android.graphics.drawable.BitmapDrawable value) Get the size in bytes of a bitmap in a BitmapDrawable.
static java.io.File	getDiskCacheDir(android.content.Context context, java.lang.String uniqueName) Get a usable cache directory (external if available, internal otherwise).
static java.io.File	getExternalCacheDir(android.content.Context context) Get the external app cache directory.
static long	getUsableSpace(java.io.File path) Check how much usable space is available at a given path.
static java.lang.String	hashKeyForDisk(java.lang.String key) A hashing method that changes a string (like a URL) into a hash suitable for using as a disk filename.
static boolean	isExternalStorageRemovable() Check if external storage is built-in or removable.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

方法详细资料

calculateInSampleSize

public static int calculateInSampleSize(android.graphics.BitmapFactory.Options options,
                                        int reqWidth,
                                        int reqHeight)

Calculate an inSampleSize for use in a BitmapFactory.Options object when decoding bitmaps using the decode* methods from BitmapFactory. This implementation calculates the closest inSampleSize that is a power of 2 and will result in the final decoded bitmap having a width and height equal to or larger than the requested width and height.

参数:

options - An options object with out* params already populated (run through a decode* method with inJustDecodeBounds==true

reqWidth - The requested width of the resulting bitmap

reqHeight - The requested height of the resulting bitmap

返回:

The value to be used for inSampleSize

hashKeyForDisk

public static java.lang.String hashKeyForDisk(java.lang.String key)

A hashing method that changes a string (like a URL) into a hash suitable for using as a disk filename.

getBitmapSize

public static int getBitmapSize(android.graphics.drawable.BitmapDrawable value)

Get the size in bytes of a bitmap in a BitmapDrawable. Note that from Android 4.4 (KitKat) onward this returns the allocated memory size of the bitmap which can be larger than the actual bitmap data byte count (in the case it was re-used).

参数:

value -

返回:

size in bytes

getExternalCacheDir

public static java.io.File getExternalCacheDir(android.content.Context context)

Get the external app cache directory.

参数:

context - The context to use

返回:

The external cache dir

isExternalStorageRemovable

public static boolean isExternalStorageRemovable()

Check if external storage is built-in or removable.

返回:

True if external storage is removable (like an SD card), false otherwise.

getDiskCacheDir

public static java.io.File getDiskCacheDir(android.content.Context context,
                                           java.lang.String uniqueName)

Get a usable cache directory (external if available, internal otherwise).

参数:

context - The context to use

uniqueName - A unique directory name to append to the cache dir

返回:

The cache dir

getUsableSpace

public static long getUsableSpace(java.io.File path)

Check how much usable space is available at a given path.

参数:

path - The path to check

返回:

The space available in bytes