Question

要检查2个EditTexts（ accName 和 accMoney ）是否为空，以便启用按钮（ btnCrAcc ）。

尝试像下面的代码一样。但它实际上并没有检查我想要的方式。当我更改accMoney字段时，它会检查两个EditTexts（但之后我可以将accName更改为“”，并且无论如何都会启用Button。

我认为一种可能的解决方案是为两个字段设置addTextChangedListener，但它会消耗更多内存？（告诉我：这是一个不错的选择？）

如果有人告诉我如何正确地做到这一点，我真的很感激

我有这段代码：

  protected void onCreate(Bundle savedInstanceState) {
         //..
         accName = (EditText) findViewById(R.id.txtName);
        accMoney = (EditText) findViewById(R.id.txtMoney);
         accDescr = (EditText) findViewById(R.id.txtDescr);
         accsListView = (ListView) findViewById(R.id.listView);
         //..
        final Button btnCrAcc = (Button) findViewById(R.id.btnCreateAccount);

    accMoney.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            btnCrAcc.setEnabled(!accName.getText().toString().trim().isEmpty());
            btnCrAcc.setEnabled(!accMoney.getText().toString().trim().isEmpty()); // check this
        }

        @Override
        public void afterTextChanged(Editable editable) {

        }
    });
}

Answer 1

试试这个：

TextWatcher watcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
            btnCrAcc.setEnabled(!accName.getText().toString().trim().isEmpty() && !accMoney.getText().toString().trim().isEmpty());
        }

        @Override
        public void afterTextChanged(Editable editable) {

        }
    };

accMoney.addTextChangedListener(watcher);
accName.addTextChangedListener(watcher;

Answer 2

创建一个implmenting TextWatcher的类：

  private class MyTextWatcher implements TextWatcher {

        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
             // check for both edittexts if any of them is empty than disable the button
             btnCrAcc.setEnabled(!accName.getText().toString().trim().isEmpty() && !accMoney.getText().toString().trim().isEmpty());
        }

        @Override
        public void afterTextChanged(Editable editable) {

        }
   }

比使用textwatcher两个edittexts：

MyTextWatcher myTextWatcher = new MyTextWatcher();

accName.addTextChangedListener(myTextWatcher);
accMoney.addTextChangedListener(myTextWatcher);

Answer 3

试试这个：

if(accName.getText().length() == 0 || accMoney.getText().length() == 0) {
    //do your stuff
}

Answer 4

您可以使用单个TextWatcher实例：

TextWatcher myWatcher = new TextWatcher() {
    @Override 
    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
    } 

    @Override 
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
    } 

    @Override 
    public void afterTextChanged(Editable editable) {
        btnCrAcc.setEnabled(!accName.getText().toString().trim().isEmpty() && 
                            !accMoney.getText().toString().trim().isEmpty());
    } 
});

accName.addTextChangedListener(myWatcher);
accMoney.addTextChangedListener(myWatcher);

检查2个（或更多）EditTexts是否为空

4 个答案: