android自定义viewgroup实现等分格子布局

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() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubclick.onItemClick(v, index);}});}}}

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