Drawable /Bitmap、String/InputStream、Bitmap/byte[]互转

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;
}
}

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