android bitmap的 一些简单操作

/** 获取 drawable 的图片   可以循环   1.图名    2.drawable 3.包名      **/

int imgid = getResources().getIdentifier("ic_launcher", "drawable", "com.example.anywight");
text.setBackgroundResource(imgid);

/** 通过图片id获得Bitmap  **/
Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);

/** 通过 assest 获取       获得Drawable    bitmap **/
InputStream in = this.getAssets().open("ic_launcher");
Drawable da = Drawable.createFromStream(in, null);
Bitmap mm = BitmapFactory.decodeStream(in);

/** 通过 sdcard  获得   bitmap **/
Bitmap bit = BitmapFactory.decodeFile("/sdcard/android.jpg");

/** view转Bitmap **/
public static Bitmap convertViewToBitmap(View view, int bitmapWidth, int bitmapHeight){

Bitmap bitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
view.draw(new Canvas(bitmap));
return bitmap;
}

/** 将控件转换为bitmap **/
public static Bitmap convertViewToBitMap(View view){
// 打开图像缓存
view.setDrawingCacheEnabled(true);
// 必须调用measure和layout方法才能成功保存可视组件的截图到png图像文件
// 测量View大小
view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
// 发送位置和尺寸到View及其所有的子View
view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
// 获得可视组件的截图
Bitmap bitmap = view.getDrawingCache();
return bitmap;
}

public static Bitmap getBitmapFromView(View view){
Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(returnedBitmap);
Drawable bgDrawable = view.getBackground();
if (bgDrawable != null)
bgDrawable.draw(canvas);
else
canvas.drawColor(Color.WHITE);
view.draw(canvas);
return returnedBitmap;
}

/**  获取屏幕截图的bitmap对象的代码如下  **/
public Bitmap getScreenPic(View view){

View rootView = view.getRootView();
rootView.setDrawingCacheEnabled(true);
rootView.buildDrawingCache();
// 不明白为什么这里返回一个空，有帖子说不能在oncreat方法中调用
// 测量View大小
rootView.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
// 发送位置和尺寸到View及其所有的子View
rootView.layout(0, 0, rootView.getMeasuredWidth(), rootView.getMeasuredHeight());
// 解决措施，调用上面的measure和layout方法之后，返回值就不再为空
// 如果想要创建的是固定长度和宽度的呢？
Bitmap bitmap = rootView.getDrawingCache();
rootView.destroyDrawingCache();
return bitmap;
}

/** Drawable → Bitmap **/
public static Bitmap drawableToBitmap(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);
// canvas.setBitmap(bitmap);
drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
drawable.draw(canvas);
return bitmap;

}

/** bitmap → drawable **/
public static Drawable bitmapToDrawable(Context context,String filename){

Bitmap image = null;
BitmapDrawable ddd = null;
try {
AssetManager am = context.getAssets();
InputStream is = am.open(filename);
image = BitmapFactory.decodeStream(is);
ddd = new BitmapDrawable(context.getResources(), image);
is.close();
} catch (Exception e) {
}
return ddd;

}

/** byte[] → Bitmap **/
public static Bitmap byteToDrawable(Context context,byte[] bb){
Bitmap pp  = BitmapFactory.decodeByteArray(bb, 0, bb.length);
return pp;
}

/**  Bitmap → byte[]**/
public static byte[] bitmapToByte(Bitmap bitmap){

ByteArrayOutputStream baos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
byte[] yy = baos.toByteArray();
return yy;
}

/**  将text  转换成  bitmap  **/
public static Bitmap createTxtImage(String txt, int txtSize) {
Bitmap mbmpTest = Bitmap.createBitmap(txt.length() * txtSize + 4,
txtSize + 4, Config.ARGB_8888);
Canvas canvasTemp = new Canvas(mbmpTest);
Paint p = new Paint();
p.setAntiAlias(true);
p.setColor(Color.WHITE);
p.setTextSize(txtSize);
canvasTemp.drawText(txt, 2, txtSize - 2, p);
return mbmpTest;

}

/**  显示将bitmap进行缩放       **/
public Bitmap  bitmapScanel(Context context){
//通过openRawResource获取一个inputStream对象
InputStream inputStream = context.getResources().openRawResource(R.id.backageground);
//通过一个InputStream创建一个BitmapDrawable对象
BitmapDrawable drawable = new BitmapDrawable(inputStream);
//通过BitmapDrawable对象获得Bitmap对象
Bitmap bitmap = drawable.getBitmap();
//利用Bitmap对象创建缩略图
bitmap = ThumbnailUtils.extractThumbnail(bitmap, 40, 40);
return bitmap;

}

/**  放大缩小图片    **/
public static Bitmap zoomBitmap(Bitmap bitmap,int w,int h){
int width = bitmap.getWidth();
int height = bitmap.getHeight();
Matrix matrix = new Matrix();
float scaleWidht = ((float)w / width);
float scaleHeight = ((float)h / height);
matrix.postScale(scaleWidht, scaleHeight);
Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);
return newbmp;
}

/** 获得圆角图片的方法  **/
public static Bitmap getRoundedCornerBitmap(Bitmap bitmap,float roundPx){

Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap
.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(output);

final int color = 0xff424242;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);

paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);

return output;
}

/** 对 bitmap 进行裁剪     **/
public Bitmap  bitmapClip(Context context , int id , int x , int y){
Bitmap map = BitmapFactory.decodeResource(context.getResources(), id);
map = Bitmap.createBitmap(map, x, y, 120, 120);
return map;
}

/**
* 图片的倒影效果
*/
public static Bitmap createReflectedImage(Bitmap originalImage) {
final int reflectionGap = 4;

int width = originalImage.getWidth();
int height = originalImage.getHeight();

Matrix matrix = new Matrix();
matrix.preScale(1, -1);

// Create a Bitmap with the flip matrix applied to it.
// We only want the bottom half of the image
Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
height / 2, width, height / 2, matrix, false);

// Create a new bitmap with same width but taller to fit reflection
Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
(height + height / 2), Config.ARGB_8888);

// Create a new Canvas with the bitmap that's big enough for
// the image plus gap plus reflection
Canvas canvas = new Canvas(bitmapWithReflection);
// Draw in the original image
canvas.drawBitmap(originalImage, 0, 0, null);
// Draw in the gap
Paint defaultPaint = new Paint();
canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);
// Draw in the reflection
canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);

// Create a shader that is a linear gradient that covers the reflection
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0,
originalImage.getHeight(), 0, bitmapWithReflection.getHeight()
+ reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);
// Set the paint to use this shader (linear gradient)
paint.setShader(shader);
// Set the Transfer mode to be porter duff and destination in
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
// Draw a rectangle using the paint with our linear gradient
canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() + reflectionGap, paint);

return bitmapWithReflection;
}