可以实现复合控件单选的radioButton

开发中经常会遇到无良UI设计出一些莫名其妙 极度奇葩的单选按钮。android系统原生的radioButton虽然可以修改button属性和drawable属性做一些改变，但是依然不能很好的满足需求。

这时一般会考虑用复合的布局，其中嵌套了radioButton。虽然形式上满足了需求，但是这种布局放进radioGroup中 无法实现单选。

下面是从网上搬运的代码，自定义radioGroup可以自由嵌套，并实现单选。感谢原创大神。本屌仅仅搬运过来做个记录。

package com.example.minshengdemo.coustem;



import java.util.ArrayList;

import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CompoundButton;
import android.widget.LinearLayout;
import android.widget.RadioButton;

/** 可以放多种布局控件，能找到radiobutton */
public class MyRadioGroup 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;

    // 存放当前的radioButton
    private ArrayList radioButtons;

    public MyRadioGroup(Context context) {
        super(context);
        setOrientation(VERTICAL);
        init();
    }

    public MyRadioGroup(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    private void init() {
        mChildOnCheckedChangeListener = new CheckedStateTracker();
        mPassThroughListener = new PassThroughHierarchyChangeListener();
        super.setOnHierarchyChangeListener(mPassThroughListener);
        radioButtons = new ArrayList();
    }

    @Override
    public void setOnHierarchyChangeListener(OnHierarchyChangeListener listener) {
        // the user listener is delegated to our pass-through listener
        mPassThroughListener.mOnHierarchyChangeListener = listener;
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();

        // checks the appropriate radio button as requested in the XML file
        if (mCheckedId != -1) {
            mProtectFromCheckedChange = true;
            setCheckedStateForView(mCheckedId, true);
            mProtectFromCheckedChange = false;
            setCheckedId(mCheckedId);
        }
    }

    @Override
    public void addView(View child, int index, ViewGroup.LayoutParams params) {
        if (child instanceof RadioButton) {
            final RadioButton button = (RadioButton) child;
            radioButtons.add(button);

            if (button.isChecked()) {
                mProtectFromCheckedChange = true;
                if (mCheckedId != -1) {
                    setCheckedStateForView(mCheckedId, false);
                }
                mProtectFromCheckedChange = false;
                setCheckedId(button.getId());
            }
        } else if (child instanceof ViewGroup) {// 如果是复合控件
            // 遍历复合控件
            ViewGroup vg = ((ViewGroup) child);
            setCheckedView(vg);
        }

        super.addView(child, index, params);
    }

    /** 查找复合控件并设置radiobutton */
    private void setCheckedView(ViewGroup vg) {
        int len = vg.getChildCount();
        for (int i = 0; i < len; i++) {
            if (vg.getChildAt(i) instanceof RadioButton) {// 如果找到了，就设置check状态
                final RadioButton button = (RadioButton) vg.getChildAt(i);
                // 添加到容器
                radioButtons.add(button);
                if (button.isChecked()) {
                    mProtectFromCheckedChange = true;
                    if (mCheckedId != -1) {
                        setCheckedStateForView(mCheckedId, false);
                    }
                    mProtectFromCheckedChange = false;
                    setCheckedId(button.getId());
                }
            } else if (vg.getChildAt(i) instanceof ViewGroup) {// 迭代查找并设置
                ViewGroup childVg = (ViewGroup) vg.getChildAt(i);
                setCheckedView(childVg);
            }
        }
    }

    /** 查找复合控件并设置id */
    private void setCheckedId(ViewGroup vg) {
        int len = vg.getChildCount();
        for (int i = 0; i < len; i++) {
            if (vg.getChildAt(i) instanceof RadioButton) {// 如果找到了，就设置check状态
                final RadioButton button = (RadioButton) vg.getChildAt(i);
                int id = button.getId();
                // generates an id if it's missing
                if (id == View.NO_ID) {
                    id = button.hashCode();
                    button.setId(id);
                }
                button.setOnCheckedChangeListener(mChildOnCheckedChangeListener);
            } else if (vg.getChildAt(i) instanceof ViewGroup) {// 迭代查找并设置
                ViewGroup childVg = (ViewGroup) vg.getChildAt(i);
                setCheckedId(childVg);
            }
        }
    }

    /** 查找radioButton控件 */
    public RadioButton findRadioButton(ViewGroup group) {
        RadioButton resBtn = null;
        int len = group.getChildCount();
        for (int i = 0; i < len; i++) {
            if (group.getChildAt(i) instanceof RadioButton) {
                resBtn = (RadioButton) group.getChildAt(i);
            } else if (group.getChildAt(i) instanceof ViewGroup) {
                resBtn = findRadioButton((ViewGroup) group.getChildAt(i));
                findRadioButton((ViewGroup) group.getChildAt(i));
                break;
            }
        }
        return resBtn;
    }

    /** 返回当前radiobutton控件的count */
    public int getRadioButtonCount() {
        return radioButtons.size();
    }

    /** 返回当前index的radio */
    public RadioButton getRadioButton(int index) {
        return radioButtons.get(index);
    }    

    /**
     * 

     * 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()}.
     * 
     * 
     * @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);
        }
    }

    /**
     * 

     * Returns the identifier of the selected radio button in this group. Upon
     * empty selection, the returned value is -1.
     * 
     * 
     * @return the unique id of the selected radio button in this group
     * 
     * @see #check(int)
     * @see #clearCheck()
     */
    public int getCheckedRadioButtonId() {
        return mCheckedId;
    }

    /**
     * 

     * Clears the selection. When the selection is cleared, no radio button in
     * this group is selected and {@link #getCheckedRadioButtonId()} returns
     * null.
     * 
     * 
     * @see #check(int)
     * @see #getCheckedRadioButtonId()
     */
    public void clearCheck() {
        check(-1);
    }

    /**
     * 

     * Register a callback to be invoked when the checked radio button changes
     * in this group.
     * 
     * 
     * @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 MyRadioGroup.LayoutParams(getContext(), attrs);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
        return p instanceof MyRadioGroup.LayoutParams;
    }

    @Override
    protected LinearLayout.LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(LayoutParams.WRAP_CONTENT,
                LayoutParams.WRAP_CONTENT);
    }

    /**
     * 

     * 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.
     * 
     * 
     * 

     * See {@link android.R.styleable#LinearLayout_Layout LinearLayout
     * Attributes} for a list of all child view attributes that this class
     * supports.
     * 
     * 
     */
    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);
        }

        /**
         * 

         * 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.
         * 
         * 
         * @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;
            }
        }
    }

    /**
     * 

     * Interface definition for a callback to be invoked when the checked radio
     * button changed in this group.
     * 
     */
    public interface OnCheckedChangeListener {
        /**
         * 

         * Called when the checked radio button has changed. When the selection
         * is cleared, checkedId is -1.
         * 
         * 
         * @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(MyRadioGroup 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);
        }
    }

    /**
     * 

     * 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.
     * 
     */
    private class PassThroughHierarchyChangeListener implements
            ViewGroup.OnHierarchyChangeListener {
        private ViewGroup.OnHierarchyChangeListener mOnHierarchyChangeListener;

        public void onChildViewAdded(View parent, View child) {
            if (parent == MyRadioGroup.this && child instanceof RadioButton) {
                int id = child.getId();
                // generates an id if it's missing
                if (id == View.NO_ID) {
                    id = child.hashCode();
                    child.setId(id);
                }
                ((RadioButton) child)
                        .setOnCheckedChangeListener(mChildOnCheckedChangeListener);
            } else if (parent == MyRadioGroup.this
                    && child instanceof ViewGroup) {// 如果是复合控件
                // 查找并设置id
                setCheckedId((ViewGroup) child);
            }

            if (mOnHierarchyChangeListener != null) {
                mOnHierarchyChangeListener.onChildViewAdded(parent, child);
            }
        }

        public void onChildViewRemoved(View parent, View child) {
            if (parent == MyRadioGroup.this && child instanceof RadioButton) {
                ((RadioButton) child).setOnCheckedChangeListener(null);
            } else if (parent == MyRadioGroup.this
                    && child instanceof ViewGroup) {
                findRadioButton((ViewGroup) child).setOnCheckedChangeListener(
                        null);
            }
            if (mOnHierarchyChangeListener != null) {
                mOnHierarchyChangeListener.onChildViewRemoved(parent, child);
            }
        }
    }
}