android自定义viewgroup实现等分格子布局

先上效果图：

实现这样的效果：

一般的思路就是，直接写布局文件，用LinearLayout 嵌套多层子LinearLayout,然后根据权重layout_weight可以达到上面的效果

还有就是利用gridview了，但是这里的需求就是不能上下滑动，使用gridview的时候还要计算布局的高度，否则内容超出下滑；

开始我是用的第一种，直接在布局文件实现了，但是后来发现代码太多太恶心哦，所以我继承viewGroup,重写两个关键的方法：onLayout(),onMeasure()

我的大致思路：

1.计算当前视图宽度和高度，然后根据边距，算出每个布局的item需要分配的多少宽度和高度：

2.支持adapter的方式，动态添加每一项，还可以设置每一项点击事件

好了，直接上关键代码：

@Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // TODO Auto-generated method stub
        mMaxChildWidth = 0;
        mMaxChildHeight = 0;

        int modeW = 0, modeH = 0;
        if (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED)
            modeW = MeasureSpec.UNSPECIFIED;
        if (MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.UNSPECIFIED)
            modeH = MeasureSpec.UNSPECIFIED;

        final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
                MeasureSpec.getSize(widthMeasureSpec), modeW);
        final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
                MeasureSpec.getSize(heightMeasureSpec), modeH);

        count = getChildCount();
        if (count == 0) {
            super.onMeasure(childWidthMeasureSpec, childHeightMeasureSpec);
            return;
        }
        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == GONE) {
                continue;
            }

            child.measure(childWidthMeasureSpec, childHeightMeasureSpec);

            mMaxChildWidth = Math.max(mMaxChildWidth, child.getMeasuredWidth());
            mMaxChildHeight = Math.max(mMaxChildHeight,
                    child.getMeasuredHeight());
        }
        setMeasuredDimension(resolveSize(mMaxChildWidth, widthMeasureSpec),
                resolveSize(mMaxChildHeight, heightMeasureSpec));
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        // TODO Auto-generated method stub
        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);
                // System.out
                // .println("--top--" + top + ",bottom=" + (top + gridH));

            }
            top += gridH + margin;
        }
    }

要实现adapter也很简单，自定义一个接口,下面给出完整的代码

package com.allen.view;

import static android.view.View.MeasureSpec.EXACTLY;
import static android.view.View.MeasureSpec.makeMeasureSpec;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

import com.allen.mygridlayout.R;


/**
 * @author allen
 * @email jaylong1302@163.com
 * @date 2013-11-26 下午1:19:35
 * @company 富媒科技
 * @version 1.0
 * @description 格子布局(类似4.0中的gridlayout)
 */
public class MyGridLayout extends ViewGroup {
    private final String TAG = "MyGridLayout";

    int margin = 2;// 每个格子的水平和垂直间隔
    int colums = 2;
    private int mMaxChildWidth = 0;
    private int mMaxChildHeight = 0;
    int count = 0;

    GridAdatper adapter;

    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) {
        // TODO Auto-generated method stub
        mMaxChildWidth = 0;
        mMaxChildHeight = 0;

        int modeW = 0, modeH = 0;
        if (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED)
            modeW = MeasureSpec.UNSPECIFIED;
        if (MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.UNSPECIFIED)
            modeH = MeasureSpec.UNSPECIFIED;

        final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
                MeasureSpec.getSize(widthMeasureSpec), modeW);
        final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
                MeasureSpec.getSize(heightMeasureSpec), modeH);

        count = getChildCount();
        if (count == 0) {
            super.onMeasure(childWidthMeasureSpec, childHeightMeasureSpec);
            return;
        }
        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == GONE) {
                continue;
            }

            child.measure(childWidthMeasureSpec, childHeightMeasureSpec);

            mMaxChildWidth = Math.max(mMaxChildWidth, child.getMeasuredWidth());
            mMaxChildHeight = Math.max(mMaxChildHeight,
                    child.getMeasuredHeight());
        }
        setMeasuredDimension(resolveSize(mMaxChildWidth, widthMeasureSpec),
                resolveSize(mMaxChildHeight, heightMeasureSpec));
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        // TODO Auto-generated method stub
        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);
                // System.out
                // .println("--top--" + top + ",bottom=" + (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);
    }

    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) {
                    // TODO Auto-generated method stub
                    click.onItemClick(v, index);
                }
            });
        }
    }

}