安卓 EditText在用软键盘编辑点击删除键时程序无故闪退

private int num = 0;
//监听软键盘的删除键
et_name_fragmentmine.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_DEL) {
num++;
//在这里加判断的原因是点击一次软键盘的删除键,会触发两次回调事件
if (num % 2 != 0) {
String s = et_name_fragmentmine.getText().toString();
if (!TextUtils.isEmpty(s)) {
et_name_fragmentmine.setText("" + s.substring(0, s.length() - 1));
//将光标移到最后
et_name_fragmentmine.setSelection(et_name_fragmentmine.getText().length());
}
}
return true;
}
return false;
}
});