问题描述
我想在我的对话框中收听 TextView 文本更改，所以 我正在使用如下所示的 TextWatcher：
final View layout = activity.getLayoutInflater().inflate(R.layout.popup_history,container,false);
final Dialog dialog = new Dialog(context,R.style.full_screen_dialog);
dialog.setContentView(layout);
final Window window = dialog.getwindow();
WindowManager.LayoutParams layoutParams;
if (window != null) {
window.setLayout(WindowManager.LayoutParams.MATCH_PARENT,WindowManager.LayoutParams.MATCH_PARENT);
layoutParams = window.getAttributes();
if (layoutParams != null) {
layoutParams.windowAnimations = R.style.ChooserStyle;
layoutParams.gravity= Gravity.BottOM;
window.setAttributes(layoutParams);
}
}
TextView searchHistoryTV = layout.findViewById(R.id.searchHistoryTV);
searchHistoryTV.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s,int start,int count,int after) {
}
@Override
public void onTextChanged(CharSequence s,int before,int count) {
CharSequence editable = searchHistoryTV.getText();
//thereafter use this CharSequence
}
@Override
public void afterTextChanged(Editable s) {
}
});
dialog.setCanceledOnTouchOutside(true);
dialog.setCancelable(true);
dialog.show();
是否需要在对话框关闭时删除 TextWatcher，即在 dialog.setondismissListener() 中？或者如果我不删除它会怎样？
解决方法
无需特别删除任何 FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
CollectionReference usersRef = rootRef.collection("users");
Query queryUsersByName = usersRef.whereEqualTo("name","John");
queryUsersByName.get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
@Override
public void onComplete(@NonNull Task<QuerySnapshot> task) {
if (task.isSuccessful()) {
for (DocumentSnapshot document : task.getResult()) {
if (document.exists()) {
Log.d("TAG","name already exists");
} else {
//Do what you need to do
}
}
} else {
Log.d("TAG","Error getting documents: ",task.getException());
}
}
});
，一旦 listeners 解除，它里面的所有子 dialog 实例无论如何都会被销毁。因此，即使您不移除 view，也不会发生任何事情，因为它附加到 TextListener 也会被销毁 EditText。