### 一睹为快
### 需求
1.动态加载属性，如尺码，颜色，款式等
由于每件商品的属性是不确定的，有的商品的属性是颜色和尺码，有的是口味，有的是大小，所以这些属性不能直接写死到页面上。
2.动态加载属性下的标签
每个属性下的标签个数也不是一定的，比如有的商品的尺码是是S,M,XL，有的是均码，也就是每种属性的具体的内容是不一定的。
### 技术点
自定义ViewGroup，使其中的TextView可以依据内容长短自动换行，如下图所示
### 实现
### 布局
通过ListView来显示商品所有属性，每种属性作为ListView的Item。
~~~
<!-- 商品规格列表 -->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFFFFFFF"
>
<ListView
android:id="@+id/lv_property"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:divider="#C0C0C0"
android:dividerHeight="0.5px"
android:listSelector="#00000000">
</ListView>
</LinearLayout>
~~~
### 自定义ViewGroup
> 普通的LinearLayout只能横向和纵向显示控件，但是当一行显示不够时，无法自动换行，需要我们自定义布局容器。
~~~
package jczb.shoping.common;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
public class MyViewGroup extends ViewGroup {
private final static int VIEW_MARGIN=15;
public MyViewGroup(Context context, AttributeSet attrs){
super(context, attrs);
}
public MyViewGroup(Context context) {
super(context);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int stages = 1;
int stageHeight = 0;
int stageWidth = 0;
int wholeWidth = MeasureSpec.getSize(widthMeasureSpec);
for (int i = 0; i < getChildCount(); i++) {
final View child = getChildAt(i);
// measure
measureChild(child, widthMeasureSpec, heightMeasureSpec);
stageWidth += (child.getMeasuredWidth() + VIEW_MARGIN);
stageHeight = child.getMeasuredHeight();
if (stageWidth >= wholeWidth) {
stages++;
//reset stageWidth
stageWidth = child.getMeasuredWidth();
}
}
int wholeHeight = (stageHeight + VIEW_MARGIN) * stages;
// report this final dimension
setMeasuredDimension(resolveSize(wholeWidth, widthMeasureSpec),
resolveSize(wholeHeight, heightMeasureSpec));
}
private int jiange = 10;//按钮之间的间隔
@Override
protected void onLayout(boolean arg0, int arg1, int arg2, int arg3, int arg4) {
final int count = getChildCount();
int row=0;// which row lay you view relative to parent
int lengthX=arg1 ; // right position of child relative to parent
int lengthY=arg2; // bottom position of child relative to parent
for(int i=0;i<count;i++){
final View child = this.getChildAt(i);
int width = child.getMeasuredWidth();
int height = child.getMeasuredHeight();
if(i == 0){
lengthX+=width+VIEW_MARGIN;//第一个的时候不需要加
}else{
lengthX+=width+VIEW_MARGIN +jiange;//按钮之间的间隔
}
lengthY=row*(height+VIEW_MARGIN)+VIEW_MARGIN+height+arg2;
//if it can't drawing on a same line , skip to next line
if(lengthX>arg3){
lengthX=width+VIEW_MARGIN+arg1;
row++;
lengthY=row*(height+VIEW_MARGIN)+VIEW_MARGIN+height+arg2;
}
child.layout(lengthX-width, lengthY-height, lengthX, lengthY);
}
}
}
~~~
### ListView的Adapter
~~~
package jczb.shoping.adapter;
import java.util.ArrayList;
import java.util.HashMap;
import jczb.shoping.common.MyViewGroup;
import jczb.shoping.ui.R;
import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.os.Handler;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams;
import android.widget.TableLayout;
import android.widget.TextView;
public class PropertyAdapter extends BaseAdapter {
private Context mContext;
private ArrayList<HashMap<String,Object>> mList;
private ArrayList<HashMap<String,TextView[]>> mViewList;
private Drawable drawableNormal ;
private Drawable drawablePressed;
private Handler mHandler;
//用于保存用户的属性集合
private HashMap<String,String> selectProMap=new HashMap<String, String>();
/**
* 返回选中的属性
* @return
*/
public HashMap<String, String> getSelectProMap() {
return selectProMap;
}
public void setSelectProMap(HashMap<String, String> selectProMap) {
this.selectProMap = selectProMap;
}
public PropertyAdapter(Handler handler,Context context,ArrayList<HashMap<String,Object>> list){
super();
this.mHandler=handler;
this.mContext=context;
this.mList=list;
mViewList=new ArrayList<HashMap<String,TextView[]>>();
drawableNormal=mContext.getResources().getDrawable(R.drawable.tv_property_label);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return mList.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return mList.get(position);
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
// 获取list_item布局文件的视图
convertView = LayoutInflater.from(this.mContext).inflate(R.layout.lv_property_item, null,true);
holder = new ViewHolder();
// 获取控件对象
holder.tvPropName= (TextView) convertView
.findViewById(R.id.tv_property_name);
//holder.llPropContents=(LinearLayout)convertView.findViewById(R.id.ll_property_content);
//holder.tlPropContents=(TableLayout)convertView.findViewById(R.id.ll_property_content);
// 设置控件集到convertView
holder.vgPropContents= (MyViewGroup) convertView.findViewById(R.id.myviewgroup);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
if (this.mList != null) {
//HashMap<String,TextView[]> mapView=new HashMap<String, TextView[]>();
ArrayList<String> lables = (ArrayList<String>) this.mList.get(position).get("lable");
String type = (String) this.mList.get(position).get(
"type");
holder.tvPropName.setText(type);//规格名称
//动态加载标签
//判断布局中的子控件是否为0，如果不为0，就不添加了，防止ListView滚动时重复添加
if(holder.vgPropContents.getChildCount()==0){
TextView[] textViews = new TextView[lables.size()];
//设置每个标签的文本和布局
//TableRow tr=new TableRow(mContext);
for (int i = 0; i < lables.size(); i++) {
TextView textView = new TextView(mContext); textView.setGravity(17);
textView.setPadding(25,15,25,15);
textViews[i] = textView;
textViews[i].setBackgroundResource(R.drawable.tv_property_label);
textViews[i].setText(lables.get(i));
textViews[i].setTag(i);
//textViews[i].setBackgroundColor(Color.parseColor("#EE5500"));
//tr.addView(textViews[i]);
// holder.llPropContents.addView(textViews[i]);
holder.vgPropContents.addView(textViews[i]);
}
//holder.tlPropContents.addView(tr);
//绑定标签的Click事件
for(int j=0;j<textViews.length;j++){
textViews[j].setTag(textViews);
textViews[j].setOnClickListener(new LableClickListener(type));
}
//把控件存起来
// mapView.put(type, textViews);
// mViewList.add(mapView);
}
/**判断之前是否已选中标签*/
if(selectProMap.get(type)!=null){
for(int h=0;h<holder.vgPropContents.getChildCount();h++){
TextView v=(TextView) holder.vgPropContents.getChildAt(h);
if(selectProMap.get(type).equals(v.getText().toString())){
v.setBackgroundColor(Color.parseColor("#EE5500"));
v.setTextColor(Color.parseColor("#FFFFFF"));
selectProMap.put(type, v.getText().toString());
}
}
}
}
return convertView;
}
/*定义item对象*/
public class ViewHolder {
TextView tvPropName;
LinearLayout llPropContents;
MyViewGroup vgPropContents;
TableLayout tlPropContents;
}
class LableClickListener implements OnClickListener{
private String type;
public LableClickListener(String type){
this.type=type;
}
@Override
public void onClick(View v) {
TextView[] textViews=(TextView[])v.getTag();
TextView tv=(TextView)v;
for(int i=0;i<textViews.length;i++){
//让点击的标签背景变成橙色，字体颜色变为白色
if(tv.equals(textViews[i])){
textViews[i].setBackgroundColor(Color.parseColor("#EE5500"));
textViews[i].setTextColor(Color.parseColor("#FFFFFF"));
selectProMap.put(type, textViews[i].getText().toString());
}else{
//其他标签背景变成白色，字体颜色为黑色
//textViews[i].setBackgroundDrawable(drawableNormal);
textViews[i].setBackgroundResource(R.drawable.tv_property_label);
textViews[i].setTextColor(Color.parseColor("#000000"));
}
}
}
}
}
~~~
### 总结
> 这里关键就是实现自定义的ViewGroup，重写onMeasure和onLayout方法，判断新添加的控件有没有超出屏幕的宽度来决定是否要换行。
