自定义View之GridView单选 金额选择Layout-ChooseMoneyLayout

思路：

　　外层控件用的是GridView，里面每个item放一个FrameLayout，FrameLayout里面有Checkbox和ImageView，chechBox添加background实现选中效果,选中背景为透明，显示item的勾勾图标，不选中checkbox就有背景，挡住选中的勾勾。。重写GridView，实现监听和数据适配，用一个接口返回选中的数据。

代码：

ChooseMoneyLayout.java

public class ChooseMoneyLayout extends GridView {

    private int[] moneyList = {};   //数据源

    private LayoutInflater mInflater;  

    private MyAdapter adapter;   //适配器

    int defaultChoose = 0;     //默认选中项

    public ChooseMoneyLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        setData();
    }

    public void setData() {
        mInflater = LayoutInflater.from(getContext());
        //配置适配器
        adapter = new MyAdapter();
        setAdapter(adapter);
    }

    /**
     * 设置默认选择项目，
     * @param defaultChoose
     */
    public void setDefaultPositon(int defaultChoose) {
        this.defaultChoose = defaultChoose;
        adapter.notifyDataSetChanged();
    }

    /**
     * 设置数据源
     * @param moneyData
     */
    public void setMoneyData(int[] moneyData){
        this.moneyList = moneyData;
    }

    class MyAdapter extends BaseAdapter {

        private CheckBox checkBox;

        @Override
        public int getCount() {
            return moneyList.length;
        }

        @Override
        public Object getItem(int position) {
            return moneyList[position];
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
            MyViewHolder holder;
            if (convertView == null) {
                holder = new MyViewHolder();
                convertView = mInflater.inflate(R.layout.item_money_pay, parent, false);
                holder.moneyPayCb = (CheckBox) convertView.findViewById(R.id.money_pay_cb);
                convertView.setTag(holder);
            } else {
                holder = (MyViewHolder) convertView.getTag();
            }

            holder.moneyPayCb.setText(getItem(position) + "元");

            holder.moneyPayCb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    if (isChecked) {
                        //设置选中文字颜色
                        buttonView.setTextColor(getResources().getColor(R.color.light_color_blue));

                        //取消上一个选择
                        if (checkBox != null) {
                            checkBox.setChecked(false);
                        }
                        checkBox = (CheckBox) buttonView;
                    } else {
                        checkBox = null;
                        //设置不选中文字颜色
                        buttonView.setTextColor(getResources().getColor(R.color.darkgray));
                    }
                    //回调
                    listener.chooseMoney(position, isChecked, (Integer) getItem(position));
                }
            });

            if (position == defaultChoose) {
                defaultChoose = -1;
                holder.moneyPayCb.setChecked(true);
                checkBox = holder.moneyPayCb;
            }

            return convertView;
        }

        private class MyViewHolder {
            private CheckBox moneyPayCb;
        }
    }

    /**
     * 解决嵌套显示不完
     * @param widthMeasureSpec
     * @param heightMeasureSpec
     */
    @Override
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,
                MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, expandSpec);
    }

    private onChoseMoneyListener listener;

    public void setOnChoseMoneyListener(onChoseMoneyListener listener) {
        this.listener = listener;
    }

    public interface onChoseMoneyListener {
        /**
         * 选择金额返回
         *
         * @param position gridView的位置
         * @param isCheck  是否选中
         * @param moneyNum 钱数
         */
        void chooseMoney(int position, boolean isCheck, int moneyNum);
    }
}

item_money_pay.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="80dp"
    android:descendantFocusability="blocksDescendants">

<!-- 选中时候的图片 -->
    <ImageView
        android:layout_width="15dp"
        android:layout_height="15dp"
        android:layout_gravity="right|bottom"
        android:layout_marginBottom="3dp"
        android:layout_marginRight="3dp"
        android:maxHeight="9dp"
        android:maxWidth="9dp"
        android:scaleType="fitCenter"
        android:src="@drawable/money_pay_type_choose" />

    <CheckBox
        android:id="@+id/money_pay_cb"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:background="@drawable/money_pay_selector"
        android:button="@null"
        android:gravity="center"
        android:paddingBottom="2.5dp"
        android:paddingLeft="15dp"
        android:paddingRight="15dp"
        android:paddingTop="2.5dp"
        android:textSize="20sp"
        android:textColor="#ff777777"
        />

</FrameLayout>

CheckBox的background: money_pay_selector.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_pressed="true" android:drawable="@drawable/blue_border_noback_drawable"/>
    <item android:state_selected="true" android:drawable="@drawable/blue_border_noback_drawable"/>
    <item android:state_checked="true" android:drawable="@drawable/blue_border_noback_drawable"/>

    <item >

        <shape>
            <solid android:color="#ffffffff"/>
            <corners android:radius="5dp"/>
            <stroke android:color="#ffbfbfbf"
                android:width="1dp"/>
        </shape>

    </item>

</selector>

activity xml:

<com.minstone.view.ChooseMoneyLayout
            android:id="@+id/money_chose_money"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:horizontalSpacing="17dp"
            android:numColumns="3"
            android:verticalSpacing="20dp" />

activity里面代码:

private ChooseMoneyLayout moneyChoseMoney;
    private int money; //当前选择的金额

    private void initData() {
        //获取控件
        moneyChoseMoney = (ChooseMoneyLayout)findViewById(R.id.money_chose_money);
        //数设置据源
        moneyChoseMoney.setMoneyData(new int[]{30, 50, 100, 200, 300, 500,1000});
        //设置默认选中项
        moneyChoseMoney.setDefaultPositon(3);
        //金额选择监听
        moneyChoseMoney.setOnChoseMoneyListener(new ChooseMoneyLayout.onChoseMoneyListener() {
            @Override
            public void chooseMoney(int position,boolean isCheck, int moneyNum) {
                if(isCheck){
                    money = moneyNum;
                    ToastUtil.showCustomToast(PayActivity.this,money+"");
                }else{
                    money = 0;
                }
            }
        });

    }