今天做一个单选框，效果如下：
使用原始的RadioGroup可以实现布局，但因为把6个单选分为两个LinearLayout，导致无法互斥，Google官方的做法是写两个RadioGroup，但是要动态监听，感觉好麻烦，最理想的办法是自定义一个RadioGroup，一劳永逸。
原文地址：https://github.com/pheng/android_radiogroup_MutilRadioGroup
一个类足以，的确很牛逼，原理应该是拿所有嵌套布局里的RadioButton，然后动态重新组了一遍，既保证布局，又实现互斥。
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Build;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.widget.CompoundButton;
import android.widget.LinearLayout;
import android.widget.RadioButton;
import java.util.ArrayList;
import java.util.List;
public class MultiLineRadioGroup extends LinearLayout {
// holds the checked id; the selection is empty by default
private int mCheckedId = -1;
// tracks children radio buttons checked state
private CompoundButton.OnCheckedChangeListener mChildOnCheckedChangeListener;
// when true, mOnCheckedChangeListener discards events
private boolean mProtectFromCheckedChange = false;
private OnCheckedChangeListener mOnCheckedChangeListener;
private PassThroughHierarchyChangeListener mPassThroughListener;
/**
* {@inheritDoc}
*/
public MultiLineRadioGroup(Context context) {
super(context);
setOrientation(VERTICAL);
init();
}
/**
* {@inheritDoc}
*/
public MultiLineRadioGroup(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
mChildOnCheckedChangeListener = new CheckedStateTracker();
mPassThroughListener = new PassThroughHierarchyChangeListener();
super.setOnHierarchyChangeListener(mPassThroughListener);
}
/**
* {@inheritDoc}
*/
@Override
public void setOnHierarchyChangeListener(OnHierarchyChangeListener listener) {
// the user listener is delegated to our pass-through listener
mPassThroughListener.mOnHierarchyChangeListener = listener;
}
/**
* set the default checked radio button, without notification the listeners
*/
public void setCheckWithoutNotif(int id) {
if (id != -1 && (id == mCheckedId)) {
return;
}
mProtectFromCheckedChange = true;
if (mCheckedId != -1) {
setCheckedStateForView(mCheckedId, false);
}
if (id != -1) {
setCheckedStateForView(id, true);
}
mCheckedId = id;
mProtectFromCheckedChange = false;
}
@Override
public void addView(View child, int index, ViewGroup.LayoutParams params) {
List<RadioButton> btns = getAllRadioButton(child);
if (btns != null && btns.size() > 0) {
for (RadioButton button : btns) {
if (button.isChecked()) {
mProtectFromCheckedChange = true;
if (mCheckedId != -1) {
setCheckedStateForView(mCheckedId, false);
}
mProtectFromCheckedChange = false;
setCheckedId(button.getId());
}
}
}
super.addView(child, index, params);
}
/**
* get all radio buttons which are in the view
*
* @param child
*/
private List<RadioButton> getAllRadioButton(View child) {
List<RadioButton> btns = new ArrayList<RadioButton>();
if (child instanceof RadioButton) {
btns.add((RadioButton) child);
} else if (child instanceof ViewGroup) {
int counts = ((ViewGroup) child).getChildCount();
for (int i = 0; i < counts; i++) {
btns.addAll(getAllRadioButton(((ViewGroup) child).getChildAt(i)));
}
}
return btns;
}
/**
* <p>Sets the selection to the radio button whose identifier is passed in
* parameter. Using -1 as the selection identifier clears the selection;
* such an operation is equivalent to invoking {@link #clearCheck()}.</p>
*
* @param id the unique id of the radio button to select in this group
* @see #getCheckedRadioButtonId()
* @see #clearCheck()
*/
public void check(int id) {
// don't even bother
if (id != -1 && (id == mCheckedId)) {
return;
}
if (mCheckedId != -1) {
setCheckedStateForView(mCheckedId, false);
}
if (id != -1) {
setCheckedStateForView(id, true);
}
setCheckedId(id);
}
private void setCheckedId(int id) {
mCheckedId = id;
if (mOnCheckedChangeListener != null) {
mOnCheckedChangeListener.onCheckedChanged(this, mCheckedId);
}
}
private void setCheckedStateForView(int viewId, boolean checked) {
View checkedView = findViewById(viewId);
if (checkedView != null && checkedView instanceof RadioButton) {
((RadioButton) checkedView).setChecked(checked);
}
}
/**
* <p>Returns the identifier of the selected radio button in this group.
* Upon empty selection, the returned value is -1.</p>
*
* @return the unique id of the selected radio button in this group
* @attr ref android.R.styleable#MyRadioGroup_checkedButton
* @see #check(int)
* @see #clearCheck()
*/
public int getCheckedRadioButtonId() {
return mCheckedId;
}
/**
* <p>Clears the selection. When the selection is cleared, no radio button
* in this group is selected and {@link #getCheckedRadioButtonId()} returns
* null.</p>
*
* @see #check(int)
* @see #getCheckedRadioButtonId()
*/
public void clearCheck() {
check(-1);
}
/**
* <p>Register a callback to be invoked when the checked radio button
* changes in this group.</p>
*
* @param listener the callback to call on checked state change
*/
public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {
mOnCheckedChangeListener = listener;
}
/**
* {@inheritDoc}
*/
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new MultiLineRadioGroup.LayoutParams(getContext(), attrs);
}
/**
* {@inheritDoc}
*/
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p instanceof MultiLineRadioGroup.LayoutParams;
}
@Override
protected LinearLayout.LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
}
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
event.setClassName(MultiLineRadioGroup.class.getName());
}
@Override
public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
super.onInitializeAccessibilityNodeInfo(info);
info.setClassName(MultiLineRadioGroup.class.getName());
}
/**
* <p>This set of layout parameters defaults the width and the height of
* the children to {@link #WRAP_CONTENT} when they are not specified in the
* XML file. Otherwise, this class ussed the value read from the XML file.</p>
* <p/>
* <p>See
* for a list of all child view attributes that this class supports.</p>
*/
public static class LayoutParams extends LinearLayout.LayoutParams {
/**
* {@inheritDoc}
*/
public LayoutParams(Context c, AttributeSet attrs) {
super(c, attrs);
}
/**
* {@inheritDoc}
*/
public LayoutParams(int w, int h) {
super(w, h);
}
/**
* {@inheritDoc}
*/
public LayoutParams(int w, int h, float initWeight) {
super(w, h, initWeight);
}
/**
* {@inheritDoc}
*/
public LayoutParams(ViewGroup.LayoutParams p) {
super(p);
}
/**
* {@inheritDoc}
*/
public LayoutParams(MarginLayoutParams source) {
super(source);
}
/**
* <p>Fixes the child's width to
* {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT} and the child's
* height to {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT}
* when not specified in the XML file.</p>
*
* @param a the styled attributes set
* @param widthAttr the width attribute to fetch
* @param heightAttr the height attribute to fetch
*/
@Override
protected void setBaseAttributes(TypedArray a,
int widthAttr, int heightAttr) {
if (a.hasValue(widthAttr)) {
width = a.getLayoutDimension(widthAttr, "layout_width");
} else {
width = WRAP_CONTENT;
}
if (a.hasValue(heightAttr)) {
height = a.getLayoutDimension(heightAttr, "layout_height");
} else {
height = WRAP_CONTENT;
}
}
}
/**
* <p>Interface definition for a callback to be invoked when the checked
* radio button changed in this group.</p>
*/
public interface OnCheckedChangeListener {
/**
* <p>Called when the checked radio button has changed. When the
* selection is cleared, checkedId is -1.</p>
*
* @param group the group in which the checked radio button has changed
* @param checkedId the unique identifier of the newly checked radio button
*/
public void onCheckedChanged(MultiLineRadioGroup group, int checkedId);
}
private class CheckedStateTracker implements CompoundButton.OnCheckedChangeListener {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// prevents from infinite recursion
if (mProtectFromCheckedChange) {
return;
}
mProtectFromCheckedChange = true;
if (mCheckedId != -1) {
setCheckedStateForView(mCheckedId, false);
}
mProtectFromCheckedChange = false;
int id = buttonView.getId();
setCheckedId(id);
}
}
/**
* <p>A pass-through listener acts upon the events and dispatches them
* to another listener. This allows the table layout to set its own internal
* hierarchy change listener without preventing the user to setup his.</p>
*/
private class PassThroughHierarchyChangeListener implements
ViewGroup.OnHierarchyChangeListener {
private ViewGroup.OnHierarchyChangeListener mOnHierarchyChangeListener;
/**
* {@inheritDoc}
*/
@SuppressLint("NewApi")
public void onChildViewAdded(View parent, View child) {
if (parent == MultiLineRadioGroup.this) {
List<RadioButton> btns = getAllRadioButton(child);
if (btns != null && btns.size() > 0) {
for (RadioButton btn : btns) {
int id = btn.getId();
// generates an id if it's missing
if (id == View.NO_ID && Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
id = View.generateViewId();
btn.setId(id);
}
btn.setOnCheckedChangeListener(
mChildOnCheckedChangeListener);
}
}
}
if (mOnHierarchyChangeListener != null) {
mOnHierarchyChangeListener.onChildViewAdded(parent, child);
}
}
/**
* {@inheritDoc}
*/
public void onChildViewRemoved(View parent, View child) {
if (parent == MultiLineRadioGroup.this) {
List<RadioButton> btns = getAllRadioButton(child);
if (btns != null && btns.size() > 0) {
for (RadioButton btn : btns) {
btn.setOnCheckedChangeListener(null);
}
}
}
if (mOnHierarchyChangeListener != null) {
mOnHierarchyChangeListener.onChildViewRemoved(parent, child);
}
}
}
}
然后调用即可：
<com.xuehu365.xuehu.utils.MultiLineRadioGroup
android:id="@+id/type"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:background="@color/white"
android:orientation="vertical"
android:padding="10dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<RadioButton
android:id="@+id/experienceProblem"
style="@style/counsel_radio_button"
android:text="体验问题" />
<RadioButton
android:id="@+id/userAdvice"
style="@style/counsel_radio_button"
android:text="功能建议" />
<RadioButton
android:id="@+id/contentSuggest"
style="@style/counsel_radio_button"
android:text="内容意见" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<RadioButton
android:id="@+id/courseBuy"
style="@style/counsel_radio_button"
android:text="课程购买" />
<RadioButton
android:id="@+id/webProblem"
style="@style/counsel_radio_button"
android:text="网络问题" />
<RadioButton
android:id="@+id/other"
style="@style/counsel_radio_button"
android:text="其它" />
</LinearLayout>
</com.xuehu365.xuehu.utils.MultiLineRadioGroup>