android源代码学习.doc

本文由麦可网/ 收集整理，转载请注明出处。android 为 ListView Item中的组件添加事件 以及更新数据/ 部分代码如下：其中holder.count 是一个EditViewholder.price 是一个TextViewJava代码1 viewplaincopytoclipboardprint?2 Override3 publicViewgetView(finalintposition,ViewconvertView,finalViewGroupparent)4 。5 /注意该方法中的Item组件不能使用holder模式，如果用该模式，所有的组件将共享item中view的事件6 导致监听不到指定item中的view的事件，解决办法就是每次创建一个Item中的组件78 然后对于每个item使用不同的监听事件即newTextWatcher()每次都创建一个新的事件监听器910 finalViewHolderholder=newViewHolder();1112 holder.count.addTextChangedListener(newTextWatcher()13 .14 Override15 publicvoidafterTextChanged(Editables)16 /holder.price是与holder.count在同一个item的view17 holder.price.setText(.);/赋值起作用18 .19 /textTotalPrice是最后一个Item中的view20 /与holder.price不是同一个item中的view21 textTotalPrice.setText(。);/赋值无效22 /更新list23 goods.get(position).setCount(count+);24 /更新数据：条用该方法的以后，会重新执行getView方法，非局部跟新25 GoodsListAdapter.this.notifyDataSetChanged();26 );完整代码如下：Java代码1. viewplaincopytoclipboardprint?2. importjava.util.List;3.4. importorg.android.util.NumberUtils;5.6. importandroid.app.Activity;7. importandroid.text.Editable;8. importandroid.text.TextWatcher;9. importandroid.util.Log;10. importandroid.view.LayoutInflater;11. importandroid.view.View;12. importandroid.view.ViewGroup;13. importandroid.widget.BaseAdapter;14. importandroid.widget.EditText;15. importandroid.widget.TextView;16.17. importcom.mmb.shop.R;18. /*19. *购物车:商品列表20. *21. *authorwangtao22. */23. publicclassGoodsListAdapterextendsBaseAdapter24.25. privatestaticListgoods;26.27. privateLayoutInflatermInflater;28.29. privatestaticTextViewtextTotalPrice;30.31. /privateActivitycontext;32.33. publicGoodsListAdapter(Listgoods_,Activitycontext)34. goods=goods_;35. mInflater=context.getLayoutInflater();36. /this.context=context;37. 38.39. Override40. publicViewgetView(finalintposition,ViewconvertView,finalViewGroupparent)41. /最后一条显示总价42. if(position=goods.size()43. convertView=mInflater.inflate(android.R.layout.simple_list_item_1,parent,false);44. textTotalPrice=(TextView)convertView.findViewById(android.R.id.text1);45. if(goods.size()0)46. textTotalPrice.setText(总价:+calcuteTotalPrice()+);47. else48. textTotalPrice.setText(购物车为空.);49. 50. returnconvertView;51. 52.53. finalViewHolderholder=newViewHolder();54. /商品列表布局55. convertView=mInflater.inflate(R.layout.list_item_shop_car,parent,false);56. holder.id=(TextView)convertView.findViewById(R.id.goods_id);57. =(TextView)convertView.findViewById(R.id.goods_name);58. /不能使用Holder模式;必须每次都创建一个不同的EditText组件59. holder.count=(EditText)convertView.findViewById(R.id.goods_count);60. /单价61. holder.singlePrice=(TextView)convertView.findViewById(R.id.goods_single_price);62. /总价63. holder.price=(TextView)convertView.findViewById(R.id.goods_price);64.65. finalGoodsitem=goods.get(position);66. /holder.id.setText(item.getId();67. .setText(item.getName();68. holder.count.setText(item.getCount();69. holder.singlePrice.setText(item.getSinglePrice();70. floattotalPrice=Integer.valueOf(item.getCount()*Float.valueOf(item.getSinglePrice();71. holder.price.setText(价格:+totalPrice+);72. /设置没类产品的总价73. goods.get(position).setTotalPrice(totalPrice+);74.75. /添加编辑框的change事件76. holder.count.addTextChangedListener(newTextWatcher()77. Override78. publicvoidonTextChanged(CharSequences,intstart,intbefore,intcount)79. 80. Override81. publicvoidbeforeTextChanged(CharSequences,intstart,intcount,82. intafter)83. 84. Override85. publicvoidafterTextChanged(Editables)86. try/s.toString()即是文本框的值87. intcount=Integer.valueOf(s.toString();88. floatsinglePrice=Integer.valueOf(item.getSinglePrice();89. floattotalPrice=count*singlePrice;90. holder.price.setText(totalPrice+);91. goods.get(position).setTotalPrice(totalPrice+);92. textTotalPrice.setText(GoodsListAdapter.calcuteTotalPrice()+);93. goods.get(position).setCount(count+);94. /更新数据95. GoodsListAdapter.this.notifyDataSetChanged();96. /ViewconvertView=mInflater.inflate(android.R.layout.simple_list_item_1,parent,false);97. /updateItemInTotalPrice();98. catch(Exceptione)99. Log.e(xx,e.getStackTrace().toString();100. 101.102. 103. );104. returnconvertView;105. 106. /ViewHolder模式?107. staticclassViewHolder108. TextViewid;/ID109. TextViewname;/名称110. EditTextcount;/数量111. TextViewsinglePrice;/单价112. TextViewprice;/单个商品的总价113.114. 115.116. /*117. *计算所有购物车商品总价118. *return119. */120. privatefinalstaticfloatcalcuteTotalPrice()121. floatprice=0f;122. for(Goodsgs:goods)123. price+=NumberUtils.toFloat(gs.getTotalPrice();124. 125. returnprice;126. 127. /更新购物车商品总价Item非全部整合ListView128. /privatefinalvoidupdateItemInTotalPrice()129. /TextViewview=(TextView)this.getItem(goods.size();130. /view.setText(ddddd