ListView具有多种item布局――实现微信对话列
这篇文章的效果也是大家常见的，各种通讯应用的对话列表都是这种方式，像微信、whatsapp、易信、米聊等。我们这篇文章也权当为回忆，形成简单的笔记。这篇文章参考了2009年Google IO中的《TurboChargeYourUI-How to make your AndroidUI fast and efficient》和2010年Google IO中的《The World of List View》。像2009年Google IO的资料还是很前沿的，那会android开发资料很少，最重要的就是参考google发布的各种资料。
在《TurboChargeYourUI-How to make your AndroidUI fast and efficient》介绍了怎样提高listview的性能，优化了listview的加载速度。这里的item使用的是单一布局，能够实现view的重用和回收，那么多种布局文件的怎么办呢，如果再使用上面的方法，view的重用会出现问题，Android使用的BaseAdapter提供了解决多种布局文件的重用方法。
1）重写 getViewTypeCount() �C 该方法返回多少个不同的布局
2）重写 getItemViewType(int) �C 根据position返回相应的Item
博主参加了2013博客之星评选，谢谢帮助，投票猛击：
http://vote.blog.csdn.net/blogstaritem/blogstar2013/xyz_lmn
/**
* 比原来的多了getItemViewType和getViewTypeCount这两个方法，
*
* */
publicclass ChatAdapter extends BaseAdapter {
publicstaticfinal String KEY = "key";
publicstaticfinal String VALUE = "value";
publicstaticfinalint VALUE_TIME_TIP = 0;// 7种不同的布局
publicstaticfinalint VALUE_LEFT_TEXT = 1;
publicstaticfinalint VALUE_LEFT_IMAGE = 2;
publicstaticfinalint VALUE_LEFT_AUDIO = 3;
publicstaticfinalint VALUE_RIGHT_TEXT = 4;
publicstaticfinalint VALUE_RIGHT_IMAGE = 5;
publicstaticfinalint VALUE_RIGHT_AUDIO = 6;
private LayoutInflater mInflater;
private List<Message> myList;
public ChatAdapter(Context context, List<Message> myList) {
this.myList = myList;
mInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
publicint getCount() {
return myList.size();
}
@Override
public Object getItem(int arg0) {
return myList.get(arg0);
}
@Override
publiclong getItemId(int arg0) {
return arg0;
}
@Override
public View getView(int position, View convertView, ViewGroup arg2) {
Message msg = myList.get(position);
int type = getItemViewType(position);
ViewHolderTime holderTime = null;
ViewHolderRightText holderRightText = null;
ViewHolderRightImg holderRightImg = null;
ViewHolderRightAudio holderRightAudio = null;
ViewHolderLeftText holderLeftText = null;
ViewHolderLeftImg holderLeftImg = null;
ViewHolderLeftAudio holderLeftAudio = null;
if (convertView == null) {
switch (type) {
case VALUE_TIME_TIP:
holderTime = new ViewHolderTime();
convertView = mInflater.inflate(R.layout.list_item_time_tip,
null);
holderTime.tvTimeTip = (TextView) convertView
.findViewById(R.id.tv_time_tip);
holderTime.tvTimeTip.setText(msg.getValue());
convertView.setTag(holderTime);
break;
// 左边
case VALUE_LEFT_TEXT:
holderLeftText = new ViewHolderLeftText();
convertView = mInflater.inflate(R.layout.list_item_left_text,
null);
holderLeftText.ivLeftIcon = (ImageView) convertView
.findViewById(R.id.iv_icon);
holderLeftText.btnLeftText = (Button) convertView
.findViewById(R.id.btn_left_text);
holderLeftText.btnLeftText.setText(msg.getValue());
convertView.setTag(holderLeftText);
break;
case VALUE_LEFT_IMAGE:
holderLeftImg = new ViewHolderLeftImg();
convertView = mInflater.inflate(R.layout.list_item_left_iamge,
null);
holderLeftImg.ivLeftIcon = (ImageView) convertView
.findViewById(R.id.iv_icon);
holderLeftImg.ivLeftImage = (ImageView) convertView
.findViewById(R.id.iv_left_image);
holderLeftImg.ivLeftImage.setImageResource(R.drawable.test);
convertView.setTag(holderLeftImg);
break;
case VALUE_LEFT_AUDIO:
holderLeftAudio = new ViewHolderLeftAudio();
convertView = mInflater.inflate(R.layout.list_item_left_audio,
null);
holderLeftAudio.ivLeftIcon = (ImageView) convertView
.findViewById(R.id.iv_icon);
holderLeftAudio.btnLeftAudio = (Button) convertView
.findViewById(R.id.btn_left_audio);
holderLeftAudio.tvLeftAudioTime = (TextView) convertView
.findViewById(R.id.tv_left_audio_time);
holderLeftAudio.tvLeftAudioTime.setText(msg.getValue());
convertView.setTag(holderLeftAudio);
break;
// 右边
case VALUE_RIGHT_TEXT:
holderRightText= new ViewHolderRightText();
convertView = mInflater.inflate(R.layout.list_item_right_text,
null);
holderRightText.ivRightIcon = (ImageView) convertView
.findViewById(R.id.iv_icon);
holderRightText.btnRightText = (Button) convertView
.findViewById(R.id.btn_right_text);
holderRightText.btnRightText.setText(msg.getValue());
convertView.setTag(holderRightText);
break;
case VALUE_RIGHT_IMAGE:
holderRightImg= new ViewHolderRightImg();
convertView = mInflater.inflate(R.layout.list_item_right_iamge,
null);
holderRightImg.ivRightIcon = (ImageView) convertView
.findViewById(R.id.iv_icon);
holderRightImg.ivRightImage = (ImageView) convertView
.findViewById(R.id.iv_right_image);
holderRightImg.ivRightImage.setImageResource(R.drawable.test);
convertView.setTag(holderRightImg);
break;
case VALUE_RIGHT_AUDIO:
holderRightAudio=new ViewHolderRightAudio();
convertView = mInflater.inflate(R.layout.list_item_right_audio,
null);
holderRightAudio.ivRightIcon = (ImageView) convertView
.findViewById(R.id.iv_icon);
holderRightAudio.btnRightAudio = (Button) convertView
.findViewById(R.id.btn_right_audio);
holderRightAudio.tvRightAudioTime = (TextView) convertView
.findViewById(R.id.tv_right_audio_time);
holderRightAudio.tvRightAudioTime.setText(msg.getValue());
convertView.setTag(holderRightAudio);
break;
default:
break;
}
} else {
Log.d("baseAdapter", "Adapter_:"+(convertView == null) );
switch (type) {
case VALUE_TIME_TIP:
holderTime=(ViewHolderTime)convertView.getTag();
holderTime.tvTimeTip.setText(msg.getValue());
break;
case VALUE_LEFT_TEXT:
holderLeftText=(ViewHolderLeftText)convertView.getTag();
holderLeftText.btnLeftText.setText(msg.getValue());
break;
case VALUE_LEFT_IMAGE:
holderLeftImg=(ViewHolderLeftImg)convertView.getTag();
holderLeftImg.ivLeftImage.setImageResource(R.drawable.test);
break;
case VALUE_LEFT_AUDIO:
holderLeftAudio=(ViewHolderLeftAudio)convertView.getTag();
holderLeftAudio.tvLeftAudioTime.setText(msg.getValue());
break;
case VALUE_RIGHT_TEXT:
holderRightText=(ViewHolderRightText)convertView.getTag();
holderRightText.btnRightText.setText(msg.getValue());
break;
case VALUE_RIGHT_IMAGE:
holderRightImg=(ViewHolderRightImg)convertView.getTag();
holderRightImg.ivRightImage.setImageResource(R.drawable.test);
break;
case VALUE_RIGHT_AUDIO:
holderRightAudio=(ViewHolderRightAudio)convertView.getTag();
holderRightAudio.tvRightAudioTime.setText(msg.getValue());
break;
default:
break;
}
//holder = (ViewHolder) convertView.getTag();
}
return convertView;
}
/**
* 根据数据源的position返回需要显示的的layout的type
*
* type的值必须从0开始
*
* */
@Override
publicint getItemViewType(int position) {
Message msg = myList.get(position);
int type = msg.getType();
Log.e("TYPE:", "" + type);
return type;
}
/**
* 返回所有的layout的数量
*
* */
@Override
publicint getViewTypeCount() {
return7;
}
class ViewHolderTime {
private TextView tvTimeTip;// 时间
}
class ViewHolderRightText {
private ImageView ivRightIcon;// 右边的头像
private Button btnRightText;// 右边的文本
}
class ViewHolderRightImg {
private ImageView ivRightIcon;// 右边的头像
private ImageView ivRightImage;// 右边的图像
}
class ViewHolderRightAudio {
private ImageView ivRightIcon;// 右边的头像
private Button btnRightAudio;// 右边的声音
private TextView tvRightAudioTime;// 右边的声音时间
}
class ViewHolderLeftText {
private ImageView ivLeftIcon;// 左边的头像
private Button btnLeftText;// 左边的文本
}
class ViewHolderLeftImg {
private ImageView ivLeftIcon;// 左边的头像
private ImageView ivLeftImage;// 左边的图像
}
class ViewHolderLeftAudio {
private ImageView ivLeftIcon;// 左边的头像
private Button btnLeftAudio;// 左边的声音
private TextView tvLeftAudioTime;// 左边的声音时间
}
}
分享两张微信、易信的图，你也可以做成这样子。
Demo下载，请猛击。