Bitmap用法总结

Bitmap用法总结（精选2篇）

Bitmap用法总结篇1

1、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;

}

2、从资源中获取Bitmap

Resources res=getResources();

Bitmap bmp=BitmapFactory.decodeResource(res, R.drawable.pic);

3、Bitmap → byte[]

private byte[] Bitmap2Bytes(Bitmap bm){

ByteArrayOutputStream baos = new ByteArrayOutputStream();

bm.compress(Bitmap.CompressFormat.PNG, 100, baos);

return baos.toByteArray();

}

4、byte[] → Bitmap

private Bitmap Bytes2Bimap(byte[] b){

if(b.length!=0){

return BitmapFactory.decodeByteArray(b, 0, b.length);

}

else {

return null;

}

5、保存bitmap

static boolean saveBitmap2file(Bitmap bmp,String filename){

CompressFormat format= Bitmap.CompressFormat.JPEG;

int quality = 100;

OutputStream stream = null;

try {

stream = new FileOutputStream(“/sdcard/” + filename);

} catch(FileNotFoundException e){

// TODO Auto-generated catch block

Generated by Foxit PDF Creator © Foxit Software7、bitmap的用法小结

BitmapFactory.Options option = new BitmapFactory.Options();

option.inSampleSize = 2;//将图片设为原来宽高的1/2，防止内存溢出

Bitmap bm = BitmapFactory.decodeFile(“",option);//文件流

URL url = new URL(”");

InputStream is = url.openStream();

Bitmap bm = BitmapFactory.decodeStream(is);

android:scaleType：

android:scaleType是控制图片如何resized/moved来匹对ImageView的size。ImageView.ScaleType /

android:scaleType值的意义区别：

CENTER /center 按图片的原来size居中显示，当图片长/宽超过View的长/宽，则截取图片的居中部分

显示

CENTER_CROP / centerCrop 按比例扩大图片的size居中显示，使得图片长(宽)等于或大于View的长

(宽)

CENTER_INSIDE / centerInside 将图片的内容完整居中显示，通过按比例缩小或原来的size使得图片

长/宽等于或小于View的长/宽

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http:// For evaluation only.FIT_CENTER / fitCenter 把图片按比例扩大/缩小到View的宽度，居中显示

FIT_END / fitEnd 把图片按比例扩大/缩小到View的宽度，显示在View的下部分位置 FIT_START / fitStart 把图片按比例扩大/缩小到View的宽度，显示在View的上部分位置 FIT_XY / fitXY 把图片不按比例扩大/缩小到View的大小显示

MATRIX / matrix 用矩阵来绘制，动态缩小放大图片来显示。

//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;

}

//将Drawable转化为Bitmap

public static Bitmap drawableToBitmap(Drawable drawable){

int width = drawable.getIntrinsicWidth();

int height = drawable.getIntrinsicHeight();

Bitmap bitmap = Bitmap.createBitmap(width, height,drawable.getOpacity()!= PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565);

Canvas canvas = new Canvas(bitmap);

drawable.setBounds(0,0,width,height);

drawable.draw(canvas);

return bitmap;

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http:// For evaluation only.}

//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;

}

//获得带倒影的图片方法

public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap){ final int reflectionGap = 4;

int width = bitmap.getWidth();

int height = bitmap.getHeight();

Matrix matrix = new Matrix();

matrix.preScale(1,-1);

Bitmap reflectionImage = Bitmap.createBitmap(bitmap,0, height/2, width, height/2, matrix, false);

Bitmap bitmapWithReflection = Bitmap.createBitmap(width,(height + height/2), Config.ARGB_8888);

Canvas canvas = new Canvas(bitmapWithReflection);

canvas.drawBitmap(bitmap, 0, 0, null);

Paint deafalutPaint = new Paint();

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http:// For evaluation only.canvas.drawRect(0, height,width,height + reflectionGap,deafalutPaint);

canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);Paint paint = new Paint();

LinearGradient shader = new LinearGradient(0,bitmap.getHeight(), 0, bitmapWithReflection.getHeight()

+ reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);

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;

强调句型用法总结篇2

一、强调句型的基本结构:It is/was+被强调成分+that/who+其余成分

【说明】1.强调句型能强调除谓语之外的任何成分,强调谓语要用do/did/does+动词原形。2.如果被强调部分所在的句子是一般现在时, 就用is; 如果是一般过去时,则用was。3.如果被强调部分是“人”,一般用who, 但也可用that; 如果被强调部分是“人”以外的“事/物”等,仅能用that。例如:

It was because he fell ill that he was absent from class this morning.

真的是由于他病了,所以今天早上没有上课。

It is I who/that am to blame for the accident.

由于这场事故,肯定是我要受到谴责。

It is an English composition that Mary is writing now.

玛丽现在正在写的的确是一篇英语作文。

二、判断是不是强调句型的标准:如果把句中的“It is/was”和“that/who”同时去掉,句子成分不残缺,句意完整,就是强调句型,否则,就不是。例如:

It was at eight that he got up. (强调句型) 他是在八点起床的。

It was a surprise that John got full marks in the English test.(不是强调句型)

约翰在这次英语测验中得了满分是一件吃惊的事。

三、强调句型的否定句、一般疑问句和特殊疑问句:

否定句为:It is/was+not+被强调成分+that/who+其余成分.