Question

我有一个onCheckedChanged，告诉我RadioButton中的RadioGroup是否被推送。

RadioGroup rGroup = (RadioGroup)findViewById(R.id.rdgroup);
        // This will get the radiobutton in the radiogroup that is checked
        RadioButton checkedRadioButton = (RadioButton)rGroup.findViewById(rGroup.getCheckedRadioButtonId());

        rGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener()
        {
            public void onCheckedChanged(RadioGroup rGroup, int checkedId)
            {
                // This will get the radiobutton that has changed in its check state
                RadioButton checkedRadioButton = (RadioButton)rGroup.findViewById(checkedId);
                // This puts the value (true/false) into the variable
                boolean isChecked = checkedRadioButton.isChecked();
                // If the radiobutton that has changed in check state is now checked...
                if (isChecked)
                {
                    String tmp = checkedRadioButton.getText().toString();
                    //Toast t = Toast.makeText(NeuesKind.this, checkedRadioButton.getText(), Toast.LENGTH_SHORT);
                    //
                   // t.show();
                    if(tmp == "Männlich"){
                        geschlecht = "männlich";
                    }
                    if(tmp == "Weiblich"){
                        geschlecht = "weiblich";
                    }

                    Toast t1 = Toast.makeText(NeuesKind.this, geschlecht, Toast.LENGTH_SHORT);
                    t1.show();
//                  Toast t = Toast.makeText(NeuesKind.this, checkedRadioButton.getText(), Toast.LENGTH_SHORT);
//                  t.show();
                }
            }
        });

当我使用现在已经过时的第一个Toast时，它告诉我tmp是“Männlich”或“Weiblich”。当我使用第二个Toast t1时，我告诉我geschlecht为空。 geschlecht的声明是我班上最重要的，因为我在onCreate课程中也需要它。

为什么geschlecht没有取tmp的值？

Answer 1

在Java中，执行==意味着它将比较两个对象的引用。您需要通过调用字符串equals方法来实际比较对象中的文本，如下所示：

                if (tmp.equals("Männlich")) {
                    geschlecht = "männlich";
                }

                if (tmp.equals("Weiblich")) {
                    geschlecht = "weiblich";
                }

但是，这样做也会容易得多：

geschlecht = tmp.toLowerCase(); // toLowerCase will make all the characters lowercase (as you've done in your if block)

Answer 2

您没有将字符串内容与您的代码进行比较，而是将对象与equals或equalsIgnoreCase进行比较，如下所示：

if ("Männlich".equalsIgnoreCase(tmp)) {
    geschlecht = "männlich";
}
if ("Weiblich".equalsIgnoreCase(tmp)) {
    geschlecht = "weiblich";
}

Answer 3

使用tmp.compareTo ( "Mannlich" )而不是tmp ==

字符串没有价值

3 个答案: