Bitmap用法总结.docx

Bitmap用法总结

第一篇：Bitmap用法总结Bitmap用法总结1、Drawable→BitmappublicstaticBitmapdrawableToBitmap(Drawabledrawable){Bitmapbitmap=Bitmap.createBitmap（drawable.getIntrinsicWidth(),drawable.getIntrinsicHeight(),drawable.getOpacity()!=PixelFormat.OPAQUE?Bitmap.Config.ARGB_8888:Bitmap.Config.RGB_565);Canvascanvas=newCanvas(bitmap);//canvas.setBitmap(bitmap);drawable.setBounds(0,0,drawable.getIntrinsicWidth(),drawable.getIntrinsicHeight());drawable.draw(canvas);returnbitmap;}2、从资源中获取BitmapResourcesres=getResources();Bitmapbmp=BitmapFactory.decodeResource(res,R.drawable.pic);3、Bitmap→byte[]privatebyte[]Bitmap2Bytes(Bitmapbm){ByteArrayOutputStreambaos=newByteArrayOutputStream();bm.compress(Bitmap.CompressFormat.PNG,100,baos);returnbaos.toByteArray();}4、byte[]→BitmapprivateBitmapBytes2Bimap(byte[]b){if(b.length!=0){returnBitmapFactory.decodeByteArray(b,0,b.length);}else{returnnull;}}5、保存bitmapstaticbooleansaveBitmap2file(Bitmapbmp,Stringfilename){CompressFormatformat=Bitmap.CompressFormat.JPEG;intquality=100;OutputStreamstream=null;try{stream=newFileOutputStream(“/sdcard/”+filename);}catch(FileNotFoundExceptione){//TODOAuto-generatedcatchblockGeneratedbyFoxitPDFCreator©FoxitSoftware7、bitmap的用法小结BitmapFactory.Optionsoption=newBitmapFactory.Options();option.inSampleSize=2;//将图片设为原来宽高的1/2，防止内存溢出Bitmapbm=BitmapFactory.decodeFile(“",option);//文件流URLurl=newURL(”");InputStreamis=url.openStream();Bitmapbm=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GeneratedbyFoxitPDFCreator©FoxitSoftwarehttp://Forevaluationonly.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