我已经声明了我的变量，'changed' too null 以便我可以检查它是否在编辑文本更改时发生更改，
我认为的问题是，当我按下保存按钮或取消按钮时，它总是会产生 null 值，因为单击按钮时它仍然为 null。但是，我认为 textwatcher 会监听 EditText 并且即使 EditText 中没有任何更改，默认情况下它也会将 SetChanged() 更改为 false，因为它提供了“实时更新”，但显然情况并非如此，我我做错了什么？还是我应该以不同的方式处理它？有什么方法可以刷新它吗？
建议将不胜感激。
（PS 删除了一些代码以减小大小并使其看起来更容易看，所以请原谅我缺少任何大括号。此外，活动确实运行正常，因为它显示了布局。但是在按下任何按钮时都会导致它坠毁。）
public class EditNewItemActivity extends AppCompatActivity{
private Boolean changed = null;
private TextView title,content;
private Button saveBtn,cancelBtn;
private String date;
private int id;
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_edit_item);
title = (TextView) findViewById(R.id.editItemTitle);
content = (TextView) findViewById(R.id.editItemDescription);
saveBtn = (Button) findViewById(R.id.editItemSaveBtn);
cancelBtn = (Button) findViewById(R.id.editItemCancelBtn);
Bundle extras = getIntent().getExtras();
title.setText(extras.getString("title"));
content.setText(extras.getString("content"));
date = extras.getString("date");
id = extras.getInt("id");
GenericTextWatcher textWatcher = new GenericTextWatcher();
title.addTextChangedListener(textWatcher);
content.addTextChangedListener(textWatcher);
ClickEvent clickEvent = new ClickEvent();
saveBtn.setOnClickListener(clickEvent);
cancelBtn.setOnClickListener(clickEvent);
}
private class ClickEvent implements View.OnClickListener{
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.editItemSaveBtn:
save();
break;
case R.id.editItemCancelBtn:
cancel();
break;
}
}
}
private void cancel() {
if (getChanged() == null){
//This was used to simply verify that getchanged was still null.
}
if (title.getText().toString() != "" || content.getText().toString() != ""){
if (getChanged() == false) {
// if nothing has been changed let it cancel etc
}else {
}
}
}
private void save() {
if (tempTitle != "" || tempContent != "") {
if(getChanged() == true){
}
}
public Boolean getChanged() {
return changed;
}
public void setChanged(Boolean changed) {
this.changed = changed;
}
private class GenericTextWatcher implements TextWatcher{
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
Log.v("Beforetext:", s.toString());
EditNewItemActivity editItem = new EditNewItemActivity();
editItem.setChanged(false);
}
@Override
public void afterTextChanged(Editable s) {
Log.v("afterTextChanged:", s.toString());
EditNewItemActivity editItem = new EditNewItemActivity();
editItem.setChanged(true);
Log.v("Status:", editItem.getChanged().toString());
}
}