android - Android中的onTextChanged与afterTextChanged-需要实时示例

我正在阅读有关Android编程中的 TextWatcher 的信息。我无法理解afterTextChanged()和onTextChanged()之间的区别。

虽然我提到
Differences between TextWatcher 's onTextChanged, beforeTextChanged and afterTextChanged，我仍然无法想到需要使用onTextChanged()而不是afterTextChanged()的情况。

最佳答案

我在Android Dev Portal上找到了对此的解释

http://developer.android.com/reference/android/text/TextWatcher.html

**abstract void afterTextChanged(Editable s)**
This method is called to notify you that, somewhere within s, the text has been changed.

**abstract void beforeTextChanged(CharSequence s, int start, int count, int after)**
This method is called to notify you that, within s, the count characters beginning at start are about to be replaced by new text with length after.

**abstract void onTextChanged(CharSequence s, int start, int before, int count)**
This method is called to notify you that, within s, the count characters beginning at start have just replaced old text that had length before.

因此，两者之间的区别是:

我可以使用afterTextChanged 更改我的文本，而onTextChanged不允许我这样做

onTextChanged给了我更改位置的偏移量，而afterTextChanged没有