在从单选组中选择单选按钮时设置变量值答案

【问题标题】：Set a variable value on select a radio button from radio group在从单选组中选择单选按钮时设置变量值
【发布时间】：2018-03-08 17:38:25
【问题描述】：

当用户从无线电组中分别选择男性、女性或未分类时，我想将字符串变量值设置为 1,2,3。

现在我正在这样做，但即使我选择了一个单选按钮，它也会将变量值设置为null

代码：

RadioGroup genderGroup;
RadioButton male, female, unclassified;
String strGender;
genderGroup = findViewById(R.id.genderGroup);
male = findViewById(R.id.genderMale);
female = findViewById(R.id.genderFemale);
unclassified = findViewById(R.id.genderUnclassified);

if (genderGroup.getCheckedRadioButtonId() == -1) {
        strGender = null;           //no buttons selected
    } else {
        if (male.isChecked()) {     // one of the radio buttons is checked
            strGender = "1";
        } else if (female.isChecked()) {
            strGender = "2";
        } else if (unclassified.isChecked()) {
            strGender = "3";
        }
    }

当我在选择任何单选按钮后打印该值时，它显示为空。如果你知道怎么做，请帮忙:)谢谢。

已解决感谢 Nilesh。正确的代码是：

genderGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(RadioGroup group, int checkedId) {

        if (checkedId == R.id.genderMale) {
          strGender = "1";

        } else  if (checkedId == R.id.genderFemale) {
          strGender = "2";
      }

    }
});

【问题讨论】：

标签： android radio-button radio radio-group

【解决方案1】：

你需要使用RadioGroup.OnCheckedChangeListener

此组中选中的单选按钮更改时要调用的回调的接口定义。

radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(RadioGroup group, int checkedId) {
        if (checkedId == R.id.genderMale) {
            strGender = "1";
        } else  if (checkedId == R.id.genderFemale) {
            strGender = "2";
        }
    }
});

【讨论】：

【解决方案2】：

您应该按如下方式处理：

 // Is the button now checked?
boolean checked = ((RadioButton) view).isChecked();

// Check which radio button was clicked
switch(view.getId()) {
    case R.id.genderMale:
        if (checked)
            strGender = 1;
        break;
    case R.id.genderFemale:
        if (checked)
            strGender = 2;
        break;
    case R.id.genderUnclassified:
        if (checked)
            strGender = 3;
        break;
}

【讨论】：

【解决方案3】：

genderGroup.setOnCheckedChangeListener(new OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(RadioGroup group, int checkedId) {
        // find which radio button is selected
        if(checkedId == R.id.genderMale) {
            strGender = "1";
        } else if(checkedId == R.id.genderFemale) {
            strGender = "2";
        } else {
            strGender = "3";
        }
    }
});

【讨论】：

【解决方案4】：

试试这个

String  strGender =" ";

radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(RadioGroup group, int checkedId) {
        switch(checkedId){
            case R.id.genderMale:
                strGender = "1";
                break;
            case R.id.genderFemale:
                strGender = "2";
                break;
            case R.id.genderUnclassified:
                strGender = "3";
                break;
        }
    }
});

【讨论】：

【解决方案5】：

public class MainActivity extends Activity {
    RadioGroup genderGroup;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        RadioGroup genderGroup = (RadioGroup) findViewById(R.id.radioGroup1);

        genderGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() 
        {
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                switch(checkedId){
                    case R.id.radio0:
                        // do operations specific to this selection
                            strGender = "1";
                        break;
                    case R.id.radio1:
                        // do operations specific to this selection
                             strGender = "2";
                        break;
                    case R.id.radio2:
                        // do operations specific to this selection
                              strGender = "3";
                        break;
                }   
            }
        });
    }
}

【讨论】：