一、图片来源：
1.项目下的资源文件：
a.资源文件 res/drawable文件夹
b.assets文件夹 存储量较小
c.src目录下
2.网络加载
3.本地文件夹（SD卡）
二、获取方式：
a.id查找（资源文件夹下）
b.文件路径(网络路径，本地文件路径)
三、如何在代码中处理图片
a.Drawable
b.Bitmap
c.InputStream
d.byte[]
四、具体操作：
1. 图片放在sdcard中，
Bitmap imageBitmap = BitmapFactory.decodeFile(path) (path 是图
片的路径，跟目录是/sdcard)
2.res下获取bitmap
代码如下：
public Bitmap getRes(String name){
ApplicationInfo appInfo=getApplicationInfo();
int resID=getResources().getIdentifier
(name,"drawable",appInfo.packageName);//name是该图片的名
字，"drawable"是该图片存放的目录，appInfo.packageName是应用程
序的包名
return BitmapFactory.decodeResource(getResources(),resID);
}
3.图片放在src目录下
String path="com/yy/ss.png";//图片存放的路径
InputStream is=getClassLoader().getResourceAsStream(path);//得
到图片流
4.在assets下，只可以存放只读文件
InputStream is=getResources().getAssets().open(name);
5.sd卡
FileInputStreamfis = new FileInputStream(path);
BufferedInputStreambis = new BufferedInputStream(fis);
Bitmap bitmap= BitmapFactory.decodeStream(bis);
Bitmap newBit= Bitmap.createScaledBitmap(bitmap, 180, 180,
false);
6.网络加载图片
详见：http://www.devstore.cn/new/newInfo/1026.html
系列讲解
五、图片类型的相互转化
1.Bitmap与InputStream的相互转化
a.Bitmap-->InputStream
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
InputStream isBm = new ByteArrayInputStream(baos.toByteArray
());
b.InputStream --> Bitmap
public Bitmap InputStream2Bitmap(InputStream is) {
return BitmapFactory.decodeStream(is);
}
2.Bitmap与Drawable
// Drawable转换成Bitmap
public Bitmap drawable2Bitmap(Drawable drawable) {
Bitmap bitmap = Bitmap
.createBitmap(
drawable.getIntrinsicWidth(),
drawable.getIntrinsicHeight(),
drawable.getOpacity() != PixelFormat.OPAQUE ?
Bitmap.Config.ARGB_8888
: Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),
drawable.getIntrinsicHeight());
drawable.draw(canvas);
return bitmap;
}
// Bitmap转换成Drawable
public Drawable bitmap2Drawable(Bitmap bitmap) {
BitmapDrawable bd = new BitmapDrawable(bitmap);
Drawable d = (Drawable) bd;
return d;
}
3.drawable与InputStream
// Drawable转换成InputStream
public InputStream Drawable2InputStream(Drawable d) {
Bitmap bitmap = this.drawable2Bitmap(d);
return this.Bitmap2InputStream(bitmap);
}
// InputStream转换成Drawable
public Drawable InputStream2Drawable(InputStream is) {
Bitmap bitmap = this.InputStream2Bitmap(is);
return this.bitmap2Drawable(bitmap);
}
4.drawable与byte[]
// Drawable转换成byte[]
public byte[] Drawable2Bytes(Drawable d) {
Bitmap bitmap = this.drawable2Bitmap(d);
return this.Bitmap2Bytes(bitmap);
}
// byte[]转换成Drawable
public Drawable Bytes2Drawable(byte[] b) {
Bitmap bitmap = this.Bytes2Bitmap(b);
return this.bitmap2Drawable(bitmap);
}
5.bitmap与byte[]
// Bitmap转换成byte[]
public byte[] Bitmap2Bytes(Bitmap bm) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
return baos.toByteArray();
}
// byte[]转换成Bitmap
public Bitmap Bytes2Bitmap(byte[] b) {
if (b.length != 0) {
return BitmapFactory.decodeByteArray(b, 0, b.length);
}
return null;
}
6.InputStream与byte[]
// 将byte[]转换成InputStream
public InputStream Byte2InputStream(byte[] b) {
ByteArrayInputStream bais = new ByteArrayInputStream(b);
return bais;
}
// 将InputStream转换成byte[]
public byte[] InputStream2Bytes(InputStream is) {
String str = "";
byte []readByte = new byte[1024];
int readCount = -1;
try {
while ((readCount = is.read(readByte,0,1024)) != -1) {
str += new String(readByte).trim();
}
return str.getBytes();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
工具类直接下载链接：http://download.csdn.net/detail/atsince/8336495