把bitmap转换成Base64的String

public class Util {
// 计算图片的缩放值
public static int calculateInSampleSize(BitmapFactory.Options options,
int reqWidth, int reqHeight) {
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int heightRatio = Math.round((float) height
/ (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
}
return inSampleSize;
}
// 根据路径获得图片并压缩，返回bitmap用于显示
public static Bitmap getSmallBitmap(String filePath) {
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filePath, options);


// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, 480, 800);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;


return BitmapFactory.decodeFile(filePath, options);
}


// 把bitmap转换成String
public static String bitmapToString(String filePath) {
Bitmap bm = getSmallBitmap(filePath);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.JPEG, 40, baos);
byte[] b = baos.toByteArray();
return Base64.encodeToString(b, Base64.DEFAULT);
}

}

str="/storage/sdcard0/Resume/Photo/TK/160520144416.jpg";

Toast.makeText(context, Util.bitmapToString(str), 1).show();