【Android開發—電商系列】（二）：仿淘寶商品屬性標簽頁

一睹為快　　　　　

需求

1.動態加載屬性，如尺碼，顏色，款式等

　　由於每件商品的屬性是不確定的，有的商品的屬性是顏色和尺碼，有的是口味，有的是大小，所以這些屬性不能直接寫死到頁面上。

2.動態加載屬性下的標簽

　　每個屬性下的標簽個數也不是一定的，比如有的商品的尺碼是是S,M,XL，有的是均碼，也就是每種屬性的具體的內容是不一定的。

技術點

自定義ViewGroup，使其中的TextView可以依據內容長短自動換行，如下圖所示

實現

布局

通過ListView來顯示商品所有屬性，每種屬性作為ListView的Item。

自定義ViewGroup

普通的LinearLayout只能橫向和縱向顯示控件，但是當一行顯示不夠時，無法自動換行，需要我們自定義布局容器。

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;//按鈕之間的間隔
     @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();" height="child.getMeasuredHeight();" if(i="=" 0){="" lengthx+="width+VIEW_MARGIN;//第一個的時候不需要加" }else{="" +jiange;="" 按鈕之間的間隔="" }="" lengthy="row*(height+VIEW_MARGIN)+VIEW_MARGIN+height+arg2;" if="" it="" can't="" drawing="" on="" a="" same="" line="" ,="" skip="" to="" next="" 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> mList;
    private ArrayList> mViewList;
    private Drawable drawableNormal ;
    private Drawable drawablePressed;
    private Handler mHandler;

    //用於保存用戶的屬性集合
    private HashMap selectProMap=new HashMap();
    /**
     * 返回選中的屬性
     * @return
     */
    public HashMap getSelectProMap() {
        return selectProMap;
    }




    public void setSelectProMap(HashMap selectProMap) {
        this.selectProMap = selectProMap;
    }




    public PropertyAdapter(Handler handler,Context context,ArrayList> list){
        super();
        this.mHandler=handler;
        this.mContext=context;
        this.mList=list;
        mViewList=new ArrayList>();
        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) {
            // 獲取list_item布局文件的視圖
            convertView = LayoutInflater.from(this.mContext).inflate(R.layout.lv_property_item, null,true);
            holder = new ViewHolder(); 

            // 獲取控件對象
            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);
            // 設置控件集到convertView
            holder.vgPropContents= (MyViewGroup) convertView.findViewById(R.id.myviewgroup);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag(); 
        }
        if (this.mList != null) {
            //HashMap mapView=new HashMap();
            ArrayList lables = (ArrayList) this.mList.get(position).get("lable");
            String type = (String) this.mList.get(position).get(
                    "type");
            holder.tvPropName.setText(type);//規格名稱
            //動態加載標簽
            //判斷布局中的子控件是否為0，如果不為0，就不添加了，防止ListView滾動時重復添加
            if(holder.vgPropContents.getChildCount()==0){
                TextView[]  textViews = new TextView[lables.size()];
                //設置每個標簽的文本和布局
                //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);
                 //綁定標簽的Click事件
                 for(int j=0;j

總結

　　這裡關鍵就是實現自定義的ViewGroup，重寫onMeasure和onLayout方法，判斷新添加的控件有沒有超出屏幕的寬度來決定是否要換行。