首先感谢：

http://www.eoeandroid.com/thread-201857-1-1.html

public boolean dispatchKeyEvent(KeyEvent event) {

//用户按下返回键

if(event.getKeyCode() == KeyEvent.KEYCODE_BACK) {

if(event.getAction() == KeyEvent.ACTION_DOWN && event.getRepeatCount() == 0) {

Intent intent = new Intent(RegisterActivity.this, LoginActivity.class);

startActivity(intent);

overridePendingTransition(android.R.anim.fade_in,android.R.anim.fade_out);

RegisterActivity.this.finish();

}

}

return true;

}

在我的代码中，重写了一个方法去监听用户按键，最后返回的都是true，这就是只能输入无法删除的原因了，只需要把以上代码改成：

public boolean dispatchKeyEvent(KeyEvent event) {

//用户按下返回键

if(event.getKeyCode() == KeyEvent.KEYCODE_BACK) {

if(event.getAction() == KeyEvent.ACTION_DOWN && event.getRepeatCount() == 0) {

Intent intent = new Intent(RegisterActivity.this, LoginActivity.class);

startActivity(intent);

overridePendingTransition(android.R.anim.fade_in,android.R.anim.fade_out);

RegisterActivity.this.finish();

}

return false;

}

else {

return super.dispatchKeyEvent(event);

}

}