【Android】格子布局（类似锤子桌面布局）

转载：

http://www.devstore.cn/code/info/277.html

利用自定义布局实现了格子布局，用来展示选项，添加了对应的item点击监听，和“锤子”桌面效果差不多。

源码运行截图

• 效果图

源码片段

public class MyGridLayout extends ViewGroup {
    int margin = 2 ; // 每个格子的水平和垂直间隔
    int colums = 2 ;
    int count = 0 ;

    GridAdatper adapter;

    @SuppressLint ( "Recycle" )
    public MyGridLayout(Context context, AttributeSet attrs, int defStyle) {
        super (context, attrs, defStyle);
        if (attrs != null ) {
            TypedArray a = getContext().obtainStyledAttributes(attrs,
                    R.styleable.MyGridLayout);
            colums = a.getInteger(R.styleable.MyGridLayout_numColumns, 2 );
            margin = ( int ) a.getInteger(R.styleable.MyGridLayout_itemMargin, 2 );
        }
    }

    public MyGridLayout(Context context, AttributeSet attrs) {
        this (context, attrs, 0 );
    }

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

    @Override
    protected void onMeasure( int widthMeasureSpec, int heightMeasureSpec) {

        count = getChildCount();
        if (count == 0 ) {
            super .onMeasure(widthMeasureSpec, widthMeasureSpec);
            return ;
        }

        for ( int i = 0 ; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == GONE) {
                continue ;
            }

            child.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);

        }

        super .onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    @Override
    protected void onLayout( boolean changed, int l, int t, int r, int b) {
        int height = b - t; // 布局区域高度
        int width = r - l; // 布局区域宽度
        int rows = count % colums == 0 ? count / colums : count / colums + 1 ; // 行数
        if (count == 0 )
            return ;
        int gridW = (width - margin * (colums - 1 )) / colums; // 格子宽度
        int gridH = (height - margin * rows) / rows; // 格子高度

        int left = 0 ;
        int top = margin;

        for ( int i = 0 ; i < rows; i++) { // 遍历行
            for ( int j = 0 ; j < colums; j++) { // 遍历每一行的元素
                View child = this .getChildAt(i * colums + j);
                if (child == null )
                    return ;
                left = j * gridW + j * margin;
                // 如果当前布局宽度和测量宽度不一样，就直接用当前布局的宽度重新测量
                if (gridW != child.getMeasuredWidth()
                        || gridH != child.getMeasuredHeight()) {
                    child.measure(makeMeasureSpec(gridW, EXACTLY),
                            makeMeasureSpec(gridH, EXACTLY));
                }
                child.layout(left, top, left + gridW, top + gridH);
            }
            top += gridH + margin;
        }
    }

    public interface GridAdatper {
        View getView( int index);

        int getCount();
    }

    /** 设置适配器 */
    public void setGridAdapter(GridAdatper adapter) {
        this .adapter = adapter;
        // 动态添加视图
        int size = adapter.getCount();
        for ( int i = 0 ; i < size; i++) {
            addView(adapter.getView(i));
        }
    }

    public interface OnItemClickListener {
        void onItemClick(View v, int index);
    }

    /**
     * 设置item点击事件
     *
     * @param click
     */
    public void setOnItemClickListener( final OnItemClickListener click) {
        if ( this .adapter == null )
            return ;
        for ( int i = 0 ; i < adapter.getCount(); i++) {
            final int index = i;
            View view = getChildAt(i);
            view.setOnClickListener( new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    click.onItemClick(v, index);
                }
            });
        }
    }
}