Question

我想创建动态RadioGroup（带有动态广播选项）。我正在使用以下代码。

我的问题是，如何获得通过单击按钮“ 检查答案”选择的选项。如果通过XML布局添加了无线电组，则可以通过其ID来获取，但是在这种情况下，我无法这样做。

代码如下：

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <LinearLayout
        android:id="@+id/linear_layout"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:orientation="vertical"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toTopOf="@+id/button">
    </LinearLayout>

    <TextView
        android:id="@+id/answer"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toTopOf="@+id/button"
        android:textColor="#008b00"
        />

    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Check Answer"
        app:layout_constraintBottom_toBottomOf="parent"
        android:onClick="checkAnswer"
        />
</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity：

package com.example.quiz8;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    private LinearLayout linearLayout = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        linearLayout = (LinearLayout) findViewById(R.id.linear_layout);
        RadioGroup radioGroup = new RadioGroup(this);
        RadioButton radioButton;

        final String[] title = {"Male", "Female", "Other", "Secret"};

        for (int i = 0; i < title.length; i++) {
            radioButton = new RadioButton(this);
            radioButton.setId(i);
            radioButton.setText(title[i]);
            radioGroup.addView(radioButton);
        }

        linearLayout.addView(radioGroup);
    }

    public void checkAnswer(View view) {
        //get the answer here
        TextView answerText = (TextView) findViewById(R.id.answer);
        answerText.setText("You selected the option...");
    }
}

Answer 1

您只需检查所选的内容即可。

public class MainActivity extends AppCompatActivity {

    private LinearLayout linearLayout = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        linearLayout = (LinearLayout) findViewById(R.id.linear_layout);
        RadioGroup radioGroup = new RadioGroup(this);
        RadioButton radioButton;

        final String[] title = {"Male", "Female", "Other", "Secret"};

        for (int i = 0; i < title.length; i++) {
            radioButton = new RadioButton(this);
            radioButton.setId(i);
            radioButton.setText(title[i]);
            radioGroup.addView(radioButton);
            radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(RadioGroup group, int checkedId) {
                //checkedId is the RadioButton selected
            }

        }

        linearLayout.addView(radioGroup);
    }

    public void checkAnswer(View view) {
        //get the answer here
        TextView answerText = (TextView) findViewById(R.id.answer);
        answerText.setText("You selected the option...");
    }
}

Answer 2

1）您可以在OnClickListner()中添加以下代码，以检查是否单击了所需的复选框。

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

// Check which radio button was clicked
switch(view.getId()) {
    case R.id.radio_pirates:
        if (checked)
            // Pirates are the best
        break;
    case R.id.radio_ninjas:
        if (checked)
            // Ninjas rule
        break;
}

更多帮助可以在“单选按钮”文档中找到：Radio Button Documentation

2）另一种方法：更好的方法是使用RadioGroup并在其上设置侦听器以相应地更改和更新View（省去2或3或4个侦听器）。

RadioGroup radioGroup = (RadioGroup) findViewById(R.id.yourRadioGroup);        
radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener() 
{
    @Override
    public void onCheckedChanged(RadioGroup group, int checkedId) {
        // checkedId is the RadioButton selected
    }
});

Answer 3

您可以在RadioGroup上设置标签以便于查找。标签可以是任何Object。我们将在此处使用String，在您调用ViewGroup的{{1}}中必须唯一。然后在findViewWithTag()中，通过其标签检索checkAnswer()，然后获取选中的RadioGroup的文本。

RadioButton

另一种选择：private static final String RADIOGROUP_TAG = "radiogroup"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); linearLayout = (LinearLayout) findViewById(R.id.linear_layout); RadioGroup radioGroup = new RadioGroup(this); radioGroup.setTag(RADIOGROUP_TAG); RadioButton radioButton; final String[] title = {"Male", "Female", "Other", "Secret"}; for (int i = 0; i < title.length; i++) { radioButton = new RadioButton(this); radioButton.setId(i); radioButton.setText(title[i]); radioGroup.addView(radioButton); } linearLayout.addView(radioGroup); } public void checkAnswer(View view) { //get the answer here RadioGroup radioGroup = linearLayout.findViewWithTag(RADIOGROUP_TAG); int checkedId = radioGroup.getCheckedRadioButtonId(); RadioButton radioButton = radioGroup.findViewById(checkedId); String text = radioButton.getText().toString(); TextView answerText = (TextView) findViewById(R.id.answer); answerText.setText("You selected the option..." + text); }中可以将String[] title和RadioGroup作为字段。这是有道理的，因为您需要一个以上的位置。

Activity

获取选中的单选按钮

3 个答案: