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我正在寻找一个将一个单位转换为另一个单位(比如货币)的应用程序。所以它由2个编辑文本组成。一种是用户输入值,另一种是包含结果。现在,在这里,我希望在第一个编辑文本中输入值时,转换后的值出现在第二个编辑文本中,而不是使用“转换”按钮将值放入第二个编辑文本中。我怎样才能做到这一点?谢谢

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1 回答 1

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TextWatcher为此使用 a 。将其设置EditText在用户键入的位置:

myEditText1.addTextChangedListener(new TextWatcher() {

        @Override
        public void afterTextChanged(Editable s) {
                        String value = s.toString();

                        // Perform computations using this string
                        // For example: parse the value to an Integer and use this value

                        // Set the computed value to the other EditText
                        myEditText2.setText(computedValue);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(final CharSequence s, int start, int before, int count) {             

        }

    });

编辑 1

检查空字符串""

myEditText1.addTextChangedListener(new TextWatcher() {

    @Override
    public void afterTextChanged(Editable s) {
        String value = s.toString();

        if (value.equals("")) {
            myEditText1.setText("0");

            // You may not need this line, because "myEditText1.setText("0")" will
            // trigger this method again and go to else block, where, if your code is set up
            // correctly, myEditText2 will get the value 0. So, try without the next line
            // and if it doesn't work, put it back.
            myEditText2.setText("0");
        } else {

            // Perform computations using this string
            // For example: parse the value to an Integer and use this value

            // Set the computed value to the other EditText
            myEditText2.setText(computedValue);
        }
}

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {

    }

    @Override
    public void onTextChanged(final CharSequence s, int start, int before, int count){              

    }

});
于 2013-07-25T10:10:29.367 回答