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863天前如果每个item的差别比较大的话你可以多定义几个layout，然后再adapter的getView方法中加载不同的layout，如果差别不是特别大的话你可以在同一个layout里面执行控件的显示与隐藏 |
ListView具有多种item布局——实现微信对话列 |
分类： android UI（常用） 2013-12-22 19:35 11603人阅读 评论(37) 收藏 举报 |
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() – 该方法返回多少个不同的布局 |
2）重写 getItemViewType(int) – 根据position返回相应的Item |
[java] view plaincopyprint?在CODE上查看代码片派生到我的代码片 |
/** |
* 比原来的多了getItemViewType和getViewTypeCount这两个方法， |
* |
* */ |
public class ChatAdapter extends BaseAdapter { |
|
public static final String KEY = "key"; |
public static final String VALUE = "value"; |
|
public static final int VALUE_TIME_TIP = 0;// 7种不同的布局 |
public static final int VALUE_LEFT_TEXT = 1; |
public static final int VALUE_LEFT_IMAGE = 2; |
public static final int VALUE_LEFT_AUDIO = 3; |
public static final int VALUE_RIGHT_TEXT = 4; |
public static final int VALUE_RIGHT_IMAGE = 5; |
public static final int 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 |
public int getCount() { |
return myList.size(); |
} |
|
@Override |
public Object getItem(int arg0) { |
return myList.get(arg0); |
} |
|
@Override |
public long 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 |
public int 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 |
public int getViewTypeCount() { |
return 7; |
} |
|
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 |
} |
|
} |
初级程序员
by: 云代码会员 发表于：2016-10-14 02:41:05 顶(0) | 踩(0) 回复
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