我有ListView上面有某种事件。事件是按天排序的,我希望每天都有标题和日期,然后事件在下面侦听。
这是我填充该列表的方式:
ArrayList<TwoText> crs = new ArrayList<TwoText>(); crs.add(new TwoText("This will be header", event.getDate())); for (Event event : events) { crs.add(new TwoText(event.getStartString() + "-" + event.getEndString(), event.getSubject())); } arrayAdapter = new TwoTextArrayAdapter(this, R.layout.my_list_item, crs); lv1.setAdapter(arrayAdapter);
这是我的类TwoText的外观:
public class TwoText { public String classID; public String state; public TwoText(String classID, String state) { this.classID = classID; this.state = state; } }
这是我的TwoTextArrayAdapter类的外观:
import java.util.ArrayList; import android.app.Activity; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.TextView; public class TwoTextArrayAdapter extends ArrayAdapter<TwoText> { private ArrayList<TwoText> classes; private Activity con; TextView seperator; public TwoTextArrayAdapter(Activity context, int textViewResourceId, ArrayList<TwoText> classes) { super(context, textViewResourceId, classes); this.con = context; this.classes = classes; } @Override public View getView(int position, View convertView, ViewGroup parent) { View v = convertView; if (v == null) { LayoutInflater vi = (LayoutInflater) con.getSystemService(Context.LAYOUT_INFLATER_SERVICE); v = vi.inflate(R.layout.my_list_item, null); } TwoText user = classes.get(position); if (user != null) { TextView content1 = (TextView) v.findViewById(R.id.list_content1); TextView content2 = (TextView) v.findViewById(R.id.list_content2); if (content1 != null) { content1.setText(user.classID); } if(content2 != null) { content2.setText(user.state); } } return v; } }
这是my_list_item.xml
my_list_item.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <TextView style="?android:attr/listSeparatorTextViewStyle" android:id="@+id/separator" android:text="Header" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="#757678" android:textColor="#f5c227" /> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal" > <TextView android:id="@+id/list_content1" android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_margin="5dip" android:clickable="false" android:gravity="center" android:longClickable="false" android:paddingBottom="1dip" android:paddingTop="1dip" android:text="sample" android:textColor="#ff7f1d" android:textSize="17dip" android:textStyle="bold" /> <TextView android:id="@+id/list_content2" android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_margin="5dip" android:clickable="false" android:gravity="center" android:linksClickable="false" android:longClickable="false" android:paddingBottom="1dip" android:paddingTop="1dip" android:text="sample" android:textColor="#6d6d6d" android:textSize="17dip" /> </LinearLayout> </LinearLayout>
目前,我要做的是将标头添加为常规列表对象,但我想将其作为标头添加,并且在我的情况下,要标上日期。
我在xml中的标头中有以下代码:
<TextView style="?android:attr/listSeparatorTextViewStyle" android:id="@+id/separator" android:text="Header" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="#757678" android:textColor="#f5c227" />
我尝试在不需要时将其隐藏,并在必要时将其显示,但我只是弄乱了其余代码。我尝试了更多的教程,但它们也具有相同的效果。
谁能指导我如何做这种简单的方法?
下面是我如何做到这一点,键getItemViewType和getViewTypeCount的Adapter类。 getViewTypeCount返回列表中有多少种项目,在这种情况下,我们有一个标题项和一个事件项,所以两个。 getItemViewType应该返回View输入处的类型position。
getItemViewType
getViewTypeCount
Adapter
View
position
那么Android将带你传递正确类型的护理View中convertView自动。
convertView
首先,我们有一个接口,我们的两个列表项类型将实现
public interface Item { public int getViewType(); public View getView(LayoutInflater inflater, View convertView); }
然后,我们有一个适配器,其中包含 Item
public class TwoTextArrayAdapter extends ArrayAdapter<Item> { private LayoutInflater mInflater; public enum RowType { LIST_ITEM, HEADER_ITEM } public TwoTextArrayAdapter(Context context, List<Item> items) { super(context, 0, items); mInflater = LayoutInflater.from(context); } @Override public int getViewTypeCount() { return RowType.values().length; } @Override public int getItemViewType(int position) { return getItem(position).getViewType(); } @Override public View getView(int position, View convertView, ViewGroup parent) { return getItem(position).getView(mInflater, convertView); }
编辑 更好地为性能..可以滚动时注意到
private static final int TYPE_ITEM = 0; private static final int TYPE_SEPARATOR = 1; public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder = null; int rowType = getItemViewType(position); View View; if (convertView == null) { holder = new ViewHolder(); switch (rowType) { case TYPE_ITEM: convertView = mInflater.inflate(R.layout.task_details_row, null); holder.View=getItem(position).getView(mInflater, convertView); break; case TYPE_SEPARATOR: convertView = mInflater.inflate(R.layout.task_detail_header, null); holder.View=getItem(position).getView(mInflater, convertView); break; } convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } return convertView; } public static class ViewHolder { public View View; } }
然后,我们对工具进行分类,Item并为正确的布局充气。在你的情况下,你将拥有一个Header类和一个ListItem类。
public class Header implements Item { private final String name; public Header(String name) { this.name = name; } @Override public int getViewType() { return RowType.HEADER_ITEM.ordinal(); } @Override public View getView(LayoutInflater inflater, View convertView) { View view; if (convertView == null) { view = (View) inflater.inflate(R.layout.header, null); // Do some initialization } else { view = convertView; } TextView text = (TextView) view.findViewById(R.id.separator); text.setText(name); return view; } }
然后ListItem上课
public class ListItem implements Item { private final String str1; private final String str2; public ListItem(String text1, String text2) { this.str1 = text1; this.str2 = text2; } @Override public int getViewType() { return RowType.LIST_ITEM.ordinal(); } @Override public View getView(LayoutInflater inflater, View convertView) { View view; if (convertView == null) { view = (View) inflater.inflate(R.layout.my_list_item, null); // Do some initialization } else { view = convertView; } TextView text1 = (TextView) view.findViewById(R.id.list_content1); TextView text2 = (TextView) view.findViewById(R.id.list_content2); text1.setText(str1); text2.setText(str2); return view; } }
和一个简单Activity的显示它
public class MainActivity extends ListActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); List<Item> items = new ArrayList<Item>(); items.add(new Header("Header 1")); items.add(new ListItem("Text 1", "Rabble rabble")); items.add(new ListItem("Text 2", "Rabble rabble")); items.add(new ListItem("Text 3", "Rabble rabble")); items.add(new ListItem("Text 4", "Rabble rabble")); items.add(new Header("Header 2")); items.add(new ListItem("Text 5", "Rabble rabble")); items.add(new ListItem("Text 6", "Rabble rabble")); items.add(new ListItem("Text 7", "Rabble rabble")); items.add(new ListItem("Text 8", "Rabble rabble")); TwoTextArrayAdapter adapter = new TwoTextArrayAdapter(this, items); setListAdapter(adapter); } }
布局 R.layout.header
R.layout.header
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal" > <TextView style="?android:attr/listSeparatorTextViewStyle" android:id="@+id/separator" android:text="Header" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="#757678" android:textColor="#f5c227" /> </LinearLayout>
布局 R.layout.my_list_item
R.layout.my_list_item
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal" > <TextView android:id="@+id/list_content1" android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_margin="5dip" android:clickable="false" android:gravity="center" android:longClickable="false" android:paddingBottom="1dip" android:paddingTop="1dip" android:text="sample" android:textColor="#ff7f1d" android:textSize="17dip" android:textStyle="bold" /> <TextView android:id="@+id/list_content2" android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_margin="5dip" android:clickable="false" android:gravity="center" android:linksClickable="false" android:longClickable="false" android:paddingBottom="1dip" android:paddingTop="1dip" android:text="sample" android:textColor="#6d6d6d" android:textSize="17dip" /> </LinearLayout>
布局 R.layout.activity_main.xml
R.layout.activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" > <ListView android:id="@android:id/list" android:layout_width="fill_parent" android:layout_height="fill_parent" /> </RelativeLayout>
你也可以变得更ViewHolders喜欢并使用,异步加载内容或任何你喜欢的内容。
ViewHolders