我想创建动态RadioGroup(带有动态单选选项)。我正在使用以下代码进行操作。
我的问题是,如何获取通过单击“检查答案”按钮选择的选项。如果单选按钮组是通过 XML 布局添加的,那么我可以获取它的 ID,但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>
主要 Activity :
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...");
}
}
最佳答案
您可以为 RadioGroup
设置一个标签,以便能够轻松找到它。 标签可以是任何对象
。我们将在此处使用 String
,它在您调用 findViewWithTag()
的 ViewGroup
中必须是唯一的。然后在 checkAnswer()
中,您通过 tag 检索 RadioGroup
,从而获取选中的 RadioButton
的文本。
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);
}
<小时/>
另一个选项:您可以将 String[] title
和 RadioGroup
作为 Activity
中的字段。这是有道理的,因为您在多个地方都需要它们。
private final String[] title = {"Male", "Female", "Other", "Secret"};
private RadioGroup radioGroup;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
linearLayout = (LinearLayout) findViewById(R.id.linear_layout);
radioGroup = new RadioGroup(this);
RadioButton radioButton;
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
int checkedId = radioGroup.getCheckedRadioButtonId();
TextView answerText = (TextView) findViewById(R.id.answer);
// Note: make sure there is a checked RadioButton!
answerText.setText("You selected the option..." + title[checkedId]);
}
关于java - 获取选中的单选按钮,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/59039195/