EditText键盘删除字符的原理

转https://blog.csdn.net/tankai19880619/article/details/17589015
frameworks/base/core/java/view/inputmethod/InputConnection.java

public interface InputConnection {
  public boolean deleteSurroundingText(int beforeLength, int afterLength);  //删除输入的字符
  public boolean commitText(CharSequence text, int newCursorPosition);  //输入字符
  public boolean sendKeyEvent(KeyEvent event);  //注入按键
}

https://blog.csdn.net/jianguo_liao19840726/article/details/24714153