【转】Drawable /Bitmap、String/InputStream、Bitmap/byte[]

  原文：http://wuxiaolong.me/2015/08/10/Drawable-to-Bitmap/

Drawable互转Bitmap

Drawable转Bitmap

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Resources res = getResources(); Drawable drawable = res.getDrawable(R.drawable.myimage); BitmapDrawable bd = (BitmapDrawable) d; Bitmap bm = bd.getBitmap();

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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转Drawable

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Bitmap bm=xxx; //xxx根据你的情况获取 BitmapDrawable bd=BitmapDrawable(bm); BtimapDrawable是Drawable的子类，最终直接使用bd对象即可。 mPicPath//本地图片路径转成Bitmap格式 Bitmap pic = BitmapFactory.decodeFile(this.mPicPath); image.setImageBitmap(pic); 转成Bitmap格式

String与InputStream相互转换

String to InputStream

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String str = "String与InputStream相互转换"; InputStream in_nocode = new ByteArrayInputStream(str.getBytes()); InputStream in_withcode = new ByteArrayInputStream(str.getBytes("UTF-8"));

InputStream to String

这里提供几个方法。

方法1：

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public String convertStreamToString(InputStream is) { BufferedReader reader = new BufferedReader(new InputStreamReader(is)); StringBuilder sb = new StringBuilder(); String line = null; try { while ((line = reader.readLine()) != null) { sb.append(line + "/n"); } } catch (IOException e) { e.printStackTrace(); } finally { try { is.close(); } catch (IOException e) { e.printStackTrace(); } } return sb.toString(); }

方法2：

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public String inputStream2String (InputStream in) throws IOException { StringBuffer out = new StringBuffer(); byte[] b = new byte[4096]; for (int n; (n = in.read(b)) != -1;) { out.append(new String(b, 0, n)); } return out.toString(); }

方法3：

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public static String inputStream2String(InputStream is) throws IOException{ ByteArrayOutputStream baos = new ByteArrayOutputStream(); int i=-1; while((i=is.read())!=-1){ baos.write(i); } return baos.toString(); }

Bitmap 和 byte[]互转

Bitmap → byte[]

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private byte[] Bitmap2Bytes(Bitmap bm){ ByteArrayOutputStream baos = new ByteArrayOutputStream(); bm.compress(Bitmap.CompressFormat.PNG, 100, baos); return baos.toByteArray(); }

byte[] → Bitmap

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private Bitmap Bytes2Bimap(byte[] b){ if(b.length!=0){ return BitmapFactory.decodeByteArray(b, 0, b.length); } else { return null; } }