实现多行RadioGroup

Android中的RadioGroup只能横向或者纵向单行摆放。实现多行RadioGroup实际上是使用了多个RadioGroup，而同时只能有一个RadioGroup起作用。

原文地址：http://www.tutorialforandroid.com/2009/11/select-radiobutton-from-multiple.html

Select a RadioButton from Multiple RadioGroup in Android

I bounds into Radiogroup
layout question while trying out something in android. The problem is that you want a RadioButton but you don't
want it to just be either horizontally placed or vertically placed which is the default way RadioGroup does. Say you want 2 rows of 4 RadioButton, by default you cant do this with one RadioGroup, so the solution is to make 2 RadioGroup but the problem now
is that you need to handle both RadioGroup in turn that when one RadioButton is selected on one RadioGroup the other RadioGroup/s will deselect itself. To do this here is the code on how i did it (it has 3 RadioGroups), it might not be the best solution :)

private Boolean changeGroup = false;
public void onCheckedChanged(RadioGroup group, int checkedId){
if (group != null && checkedId > -1 && changeGroup == false){
if(group == frequencyGroup1){
changeGroup = true;
frequencyGroup2.clearCheck();
frequencyGroup3.clearCheck();
changeGroup = false;
}else if(group == frequencyGroup2){
changeGroup = true;
frequencyGroup1.clearCheck();
frequencyGroup3.clearCheck();
changeGroup = false;
}else if(group == frequencyGroup3){
changeGroup = true;
frequencyGroup1.clearCheck();
frequencyGroup2.clearCheck();
changeGroup = false;
}
}
}

Explanation

Create a flag stating that we mark as whether the function could be execute or not (see below)

private Boolean changeGroup = false;

On the default change function of RadioGroup, create a conditional statement that would execute the change function
of all RadioGroup only when our flag state that it can execute the next code block. By default this function will execute when you select a RadioButton on a Group and/or when you call clearCheck() of each RadioGroup, and you may not want to do that especially
when we call clearCheck.

if (group != null && checkedId > -1 && changeGroup == false){

The following code will just set the flag to true when users select a RadioButton on any group, thus when other
RadioGroup call clearCheck() the code block in the function will not be called.

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