Android - 删除整个 ImageSpan 的一部分时删除它？

Question

我通过插入 ImageSpan 将图像添加到我的 edittext。我对跨度没有透彻的了解，但似乎我的 ImageSpan 需要包装一部分文本。因此，我向 EditText 添加了一些文本，并用我的 ImageSpan 将其包装起来，它看起来很好。但是，当我退格 ImageSpan 时，它只会删除文本的一个字符，而图像会一直保留到删除整个文本为止。我如何让它只用一个退格键删除？

SpannableStringBuilder builder = new SpannableStringBuilder();
builder.append(content.getText());

String imgId = "[some useful text]"; 

int selStart = content.getSelectionStart();

builder.replace(content.getSelectionStart(), content.getSelectionEnd(), imgId);

builder.setSpan(imageSpan, selStart, selStart+imgId.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
content.setText(builder);

Answer 1

一段时间后，我找到了解决方案。试试这个代码:

private TextWatcher watcher = new TextWatcher() {
    private int spanLength = -1;

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        if (start == 0) return;
        if (count > after) {
            ImageSpan[] spans = getEditableText().getSpans(start + count, start + count, ImageSpan.class);
            if (spans == null || spans.length == 0) return;
            for (int i = 0; i < spans.length; i++) {
                int end = getEditableText().getSpanEnd(spans[i]);
                if (end != start + count) continue;
                String text = spans[i].getSource();
                spanLength = text.length() - 1;
                getEditableText().removeSpan(spans[i]);
            }
        }
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        if (spanLength > -1) {
            int length = spanLength;
            spanLength = -1;
            getEditableText().replace(start - length, start, "");
        }
    }

    @Override
    public void afterTextChanged(Editable s) {
    }
};

但是您应该像这样使用原始字符串创建 ImageStan:

ssb.setSpan(new ImageSpan(bmpDrawable, originalStr), x, x + originalStr.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);