网格RadioGroup实现

原创博客，如有转载，请注明出处，非常感谢。

RadioGroup只能横向和垂直展示RadioButton，但如果RadioButton数量比较多，一行显示不全，一列显示又觉得太丑，然后设计师们就经常要求我们网格展示。先上效果图：

img1.jpg

来，简单暴力，直接上代码：

1. 定义所需属性 attrs.xml

2. GridRadioGroup.java

/**
 * 网格RadioGroup
 * Created by admin on 2016/2/3.
 */
public class GridRadioGroup extends RadioGroup {

    private static final int VERTICAL_SPACING_DIP = 15;

    private static final int HORIZONTAL_SPACING_DIP = 10;

    private float verticalSpacing = 20;

    private float horizontalSpacing = 12;

    private int numColumns = 3;

    public GridRadioGroup(Context context) {
        this(context, null);
    }

    public GridRadioGroup(Context context, AttributeSet attrs) {
        super(context, attrs);

        TypedArray attributes = context.obtainStyledAttributes(attrs, R.styleable.GridRadioGroup);

        numColumns = attributes.getInt(R.styleable.GridRadioGroup_numColumns, numColumns);

        int tempHorSpacing = (int) (HORIZONTAL_SPACING_DIP * context.getResources().getDisplayMetrics().density);
        horizontalSpacing = attributes.getDimension(R.styleable.GridRadioGroup_horizontalSpacing, tempHorSpacing);

        int tempVerSpacing = (int) (VERTICAL_SPACING_DIP * context.getResources().getDisplayMetrics().density);
        verticalSpacing = attributes.getDimension(R.styleable.GridRadioGroup_verticalSpacing, (int) tempVerSpacing);

        attributes.recycle();

    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int childCount = getChildCount();
        int contentWidth = r - l - getPaddingRight() - getPaddingLeft();
        int itemWidth = (int) (contentWidth - horizontalSpacing * (numColumns - 1)) / numColumns;

        int x = getPaddingLeft();// 横坐标开始
        int y = 0;//纵坐标开始
        int rows = 0;
        for (int i = 0; i < childCount; i++) {
            View view = getChildAt(i);
            int height = view.getMeasuredHeight();
            x += itemWidth;

            if (i % numColumns == 0) {
                x = getPaddingLeft() + itemWidth;
                rows++;
            }

            y = rows * height + (rows - 1) * (int) verticalSpacing + getPaddingTop();

            view.layout(x - itemWidth, y - height, x, y);

            x += horizontalSpacing;
        }

    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int childCount = getChildCount();
        int specWidth = MeasureSpec.getSize(widthMeasureSpec);
        int contentWidth = specWidth - getPaddingRight() - getPaddingLeft();
        int itemWidth = (int) (contentWidth - horizontalSpacing * (numColumns - 1)) / numColumns;

        int y = 0;//纵坐标开始
        int rows = 0;
        for (int i = 0; i < childCount; i++) {
            View child = getChildAt(i);
            child.measure(MeasureSpec.makeMeasureSpec(itemWidth, MeasureSpec.EXACTLY), MeasureSpec.UNSPECIFIED);
            int height = child.getMeasuredHeight();

            if (i % numColumns == 0) {
                rows++;
            }

            y = rows * height + (rows - 1) * (int) verticalSpacing + getPaddingTop() + getPaddingBottom();
        }

        setMeasuredDimension(specWidth, y);
    }

}

3. 大功告成

img2.png

img3.png

4.最后

最近整理公司项目，发现以前写了很多控件，都没有保存，所以现在打算把自己曾经写过的一些东西都写成博客，一方面方便自己以后项目中遇到类似的需求可以直接拿来用，另外一方面当作经验分享吧，顺便锻炼下自己的写作能力。。。