在Dialog中Spinner和EditText不为空时启用Button

Question

在我的AlertDialog中，我有一个Spinner和一个EditText。我试图禁用对话框的正面按钮

1. Spinner中的选定项目是“选择货币”（“选择货币”是我的数组中的第一项，Spinner设置为将String currencyName返回为“”）或
2. EditText为空。

在下面的代码中，如果我在Spinner中选择项目之前在EditText中输入，则正面按钮保持禁用状态。我不知道如何让这两个一起工作。

任何帮助都感激不尽。谢谢。

private void openDialog(){
    LayoutInflater inflater = LayoutInflater.from(MainActivity.this);
    View subView = inflater.inflate(R.layout.dialog_layout, null);
    final EditText subEditTextExchangeRate = subView.findViewById(R.id.textInputExchangeRate);
    final Spinner subSpinner = subView.findViewById(R.id.spinner);

    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.currency, android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    subSpinner.setAdapter(adapter);
    subSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            if(parent.getItemAtPosition(position).equals("Select currency")){
                currencyName = "";

            }else {
                currencyName = parent.getItemAtPosition(position).toString();
            }
        }
        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });

    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setView(subView);

    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            exchangeRate = subEditTextExchangeRate.getText().toString();
            st2 = exchangeRate;
        }
    });

    builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

        }
    });


    final AlertDialog alertDialog = builder.create();
    alertDialog.show();

    alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);
    subEditTextExchangeRate.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            String exchangeRateInput = subEditTextExchangeRate.getText().toString();
            alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(!exchangeRateInput.isEmpty() && !currencyName.isEmpty()); 
        }//This is the logic that I am looking for but the method is watching only EditText

        @Override
        public void afterTextChanged(Editable s) {

        }
    });
}

Answer 1

请在下面的代码中尝试只进行一次更改，将其放在subSpinner.setOnItemSelectedListener下面的行中，并请全局声明alertDialog。

alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(!exchangeRateInput.isEmpty() && !currencyName.isEmpty());

这是你的代码。

private void openDialog(){
    LayoutInflater inflater = LayoutInflater.from(MainActivity.this);
    View subView = inflater.inflate(R.layout.dialog_layout, null);
    final EditText subEditTextExchangeRate = subView.findViewById(R.id.textInputExchangeRate);
    final Spinner subSpinner = subView.findViewById(R.id.spinner);

    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.currency, android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    subSpinner.setAdapter(adapter);
    subSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            if(parent.getItemAtPosition(position).equals("Select currency")){
                currencyName = "";

            }else {
                currencyName = parent.getItemAtPosition(position).toString();
            }
            alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(!exchangeRateInput.isEmpty() && !currencyName.isEmpty()); 
        }
        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });

    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setView(subView);

    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            exchangeRate = subEditTextExchangeRate.getText().toString();
            st2 = exchangeRate;
        }
    });

    builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

        }
    });


    alertDialog = builder.create();
    alertDialog.show();

    alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);
    subEditTextExchangeRate.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            String exchangeRateInput = subEditTextExchangeRate.getText().toString();
            alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(!exchangeRateInput.isEmpty() && !currencyName.isEmpty()); 
        }//This is the logic that I am looking for but the method is watching only EditText

        @Override
        public void afterTextChanged(Editable s) {

        }
    });
}

Answer 2

你应该调用你的微调器的按钮启用/禁用逻辑Spinner.onItemSelected。截至目前，您只在EditText.onTextChanged检查逻辑。

1. 在AlertDialog和Spinner上设置监听器之前声明你的EditText。
2. 在Spinner.onItemSelected中添加您的逻辑以启用或禁用按钮。
3. 在EditText.onTextChanged中添加您的逻辑以启用或禁用按钮。

Answer 3

如果你改变你的代码，你可以使你的代码工作，

    Button button = dialog.getButton(AlertDialog.BUTTON_POSITIVE);
    button.setEnabled(false);
        subEditTextExchangeRate.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
            if(s.length>0 && !TextUtils.isEmpty(currencyName )){
            button.setEnabled(true);
            // your logic
           }else{
            button.setEnabled(false);
            // your logic
            }


            @Override
            public void afterTextChanged(Editable s) {

            }
        });

- >这会做你的工作。