将位图转换为文件
我明白，使用BitmapFactory可以将文件转换为位图，但有什么办法将位图图像转换为文件？
尝试这个：
bitmap.compress(Bitmap.CompressFormat.PNG, quality, outStream);
看到这个
希望它能帮助你：
//create a file to write bitmap data File f = new File(context.getCacheDir(), filename); f.createNewFile(); //Convert bitmap to byte array Bitmap bitmap = your bitmap; ByteArrayOutputStream bos = new ByteArrayOutputStream(); bitmap.compress(CompressFormat.PNG, 0 /*ignored for PNG*/, bos); byte[] bitmapdata = bos.toByteArray(); //write the bytes in file FileOutputStream fos = new FileOutputStream(f); fos.write(bitmapdata); fos.flush(); fos.close();
File file = new File("path"); OutputStream os = new BufferedOutputStream(new FileOutputStream(file)); bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os); os.close();
将Bitmap转换为File需要在后台完成（不在主线程中），如果bitmap很大，它会特别挂起用户界面
File file; public class fileFromBitmap extends AsyncTask<Void, Integer, String> { Context context; Bitmap bitmap; String path_external = Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg"; public fileFromBitmap(Bitmap bitmap, Context context) { this.bitmap = bitmap; this.context= context; } @Override protected void onPreExecute() { super.onPreExecute(); // before executing doInBackground // update your UI // exp; make progressbar visible } @Override protected String doInBackground(Void... params) { ByteArrayOutputStream bytes = new ByteArrayOutputStream(); bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bytes); file = new File(Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg"); try { FileOutputStream fo = new FileOutputStream(file); fo.write(bytes.toByteArray()); fo.flush(); fo.close(); } catch (IOException e) { e.printStackTrace(); } return null; } @Override protected void onPostExecute(String s) { super.onPostExecute(s); // back to main thread after finishing doInBackground // update your UI or take action after // exp; make progressbar gone sendFile(file); } }
调用它
new fileFromBitmap(my_bitmap, getApplicationContext());
你必须使用onPostExecute的file 。
要更改要存储在caching中的file目录replace行：
file = new File(Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg");
与：
file = new File(context.getCacheDir(), "temporary_file.jpg");
