Android实现EditText中添加和删除bitmap的方法

SpannableString mSpan1 = new SpannableString("1");
/*
* this is add bitmap on edit text
*/
private void displayBitmapOnText(Bitmap thumbnailBitmap) {
if(thumbnailBitmap == null)
return;
    int start = mEditText.getSelectionStart();
    mSpan1.setSpan(new ImageSpan(thumbnailBitmap) , mSpan1.length() - 1, mSpan1.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
//    mSpan1.toString();
    if(mEditText != null) {
      Editable et = mEditText.getText();
      et.insert(start, mSpan1);
      mEditText.setText(et);
      mEditText.setSelection(start + mSpan1.length());
    }
    mEditText.setLineSpacing(10f, 1f);
}
/*
* this is delete bitmap on edit text
* from end to start
*/
private void deleteEditTextSpan() {
    Spanned s = mEditText.getEditableText();
    ImageSpan[] imageSpan = s.getSpans(0, s.length(), ImageSpan.class); 
    for (int i = imageSpan.length - 1; i >= 0; i--) {
      if(i == imageSpan.length - 1) {
        int start = s.getSpanStart(imageSpan[i]);
        int end = s.getSpanEnd(imageSpan[i]);
        Editable et = mEditText.getText();
        et.delete(start, end);
      }
    }
    mEditText.invalidate();
}