上接系出名门Android(8) - 控件(View)之TextSwitcher, Gallery, ImageSwitcher, GridView, ListView - android

5、ListView 的 Demo
main_list_adapter.xml <? xml version ="1.0" encoding ="utf-8" ?>

< LinearLayout xmlns:android ="http://schemas.android.com/apk/res/android"
android:orientation ="horizontal" android:layout_width ="fill_parent"
android:layout_height ="fill_parent" >

< TextView android:id ="@+id/text" android:layout_width ="wrap_content"
android:layout_height ="wrap_content" android:textSize ="16sp" >
</ TextView >

</ LinearLayout > MainListAdapter.java package com.webabcd.view;

import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

// 继承 BaseAdapter 以实现自定义的列表适配器
public class MainListAdapter extends BaseAdapter {

private LayoutInflater mInflater;
private List<String> mData;

public MainListAdapter(Context context, List<String> data) {
mInflater = LayoutInflater.from(context);
mData = data;
}

@Override
public int getCount() {
return mData.size();
}

@Override
public Object getItem( int position) {
return mData.get(position);
}

@Override
public long getItemId( int position) {
return position;
}

@Override
public View getView( int position, View convertView, ViewGroup parent) {

TextView text;

if (convertView == null) {
// 指定一个 layout 作为自定义列表适配器的 layout
convertView = mInflater.inflate(R.layout.main_list_adapter, null);
text = (TextView) convertView.findViewById(R.id.text);
convertView.setTag(text);
} else {
text = (TextView) convertView.getTag();
}

String mItem = mData.get(position);
text.setText(mItem);

return convertView;
}
} Main.java package com.webabcd.view;

import java.util.ArrayList;
import java.util.List;

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ListView;

// 此处要继承 ListActivity ，用以实现 ListView 的功能
public class Main extends ListActivity {

private List<String> mData;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

setTheme(android.R.style.Theme_Light);
setContentView(R.layout.main);
mData = getData();

// 使用自定义的列表适配器来展现数据
MainListAdapter adapter = new MainListAdapter( this, mData);

// 如需使用系统内置的列表适配器，则可以使用类似如下的方法
// ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1, mData);

this.setListAdapter(adapter);
}

// ListView 的数据源
private List<String> getData(){
List<String> items = new ArrayList<String>();

items.add( "TextView");
items.add( "Button");
items.add( "ImageButton");
items.add( "ImageView");
items.add( "CheckBox");
items.add( "RadioButton");
items.add( "AnalogClock");
items.add( "DigitalClock");
items.add( "DatePicker");
items.add( "TimePicker");
items.add( "ToggleButton");
items.add( "EditText");
items.add( "ProgressBar");
items.add( "SeekBar");
items.add( "AutoCompleteTextView");
items.add( "MultiAutoCompleteTextView");
items.add( "ZoomControls");
items.add( "Include");
items.add( "VideoView");
items.add( "WebView");
items.add( "RatingBar");
items.add( "Tab");
items.add( "Spinner");
items.add( "Chronometer");
items.add( "ScrollView");
items.add( "TextSwitcher");
items.add( "ListView");
items.add( "Gallery");
items.add( "ImageSwitcher");
items.add( "GridView");
items.add( "ExpandableList");

return items;
}

// ListView 中某项被选中后的逻辑
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
Intent intent = new Intent();
intent.setClassName( this, "com.webabcd.view._" + mData.get(position));

startActivityForResult(intent, 0);
}
} 6、ExpandableList 的 Demo
_ExpandableList.java package com.webabcd.view;

import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.Gravity;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ExpandableListView.ExpandableListContextMenuInfo;

// ExpandableList - 可展开/收缩列表
// 继承 ExpandableListActivity 以实现列表的可展开/收缩的功能
public class _ExpandableList extends ExpandableListActivity {

private ExpandableListAdapter mAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);

setTitle( "ExpandableList");

mAdapter = new MyExpandableListAdapter();
setListAdapter(mAdapter);
registerForContextMenu( this.getExpandableListView());
}

// 为列表的每一项创建上下文菜单（即长按后呼出的菜单）
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
menu.setHeaderTitle( "ContextMenu");
menu.add(0, 0, 0, "ContextMenu");
}

// 单击上下文菜单后的逻辑
@Override
public boolean onContextItemSelected(MenuItem item) {
ExpandableListContextMenuInfo info = (ExpandableListContextMenuInfo) item.getMenuInfo();
String title = ((TextView) info.targetView).getText().toString();

int type = ExpandableListView.getPackedPositionType(info.packedPosition);
if (type == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {
int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);
int childPos = ExpandableListView.getPackedPositionChild(info.packedPosition);

Toast.makeText( this, title + " - Group Index: " + groupPos + " Child Index: " + childPos, Toast.LENGTH_SHORT).show();

return true;
} else if (type == ExpandableListView.PACKED_POSITION_TYPE_GROUP) {
int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);
Toast.makeText( this, title + " - Group Index: " + groupPos, Toast.LENGTH_SHORT).show();

return true;
}

return false;
}

public class MyExpandableListAdapter extends BaseExpandableListAdapter {

// 父列表数据
private String[] groups =
{
"group1",
"group2",
"group3",
"group4"
};
// 子列表数据
private String[][] children =
{
{ "child1" },
{ "child1", "child2" },
{ "child1", "child2", "child3" },
{ "child1", "child2", "child3", "child4" }
};

@Override
public Object getChild( int groupPosition, int childPosition) {
return children[groupPosition][childPosition];
}

@Override
public long getChildId( int groupPosition, int childPosition) {
return childPosition;
}

@Override
public int getChildrenCount( int groupPosition) {
return children[groupPosition].length;
}

// 取子列表中的某一项的 View
@Override
public View getChildView( int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
TextView textView = getGenericView();
textView.setText(getChild(groupPosition, childPosition).toString());
return textView;
}

@Override
public Object getGroup( int groupPosition) {
return groups[groupPosition];
}

@Override
public int getGroupCount() {
return groups.length;
}

@Override
public long getGroupId( int groupPosition) {
return groupPosition;
}

// 取父列表中的某一项的 View
@Override
public View getGroupView( int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
TextView textView = getGenericView();
textView.setText(getGroup(groupPosition).toString());
return textView;
}

@Override
public boolean hasStableIds() {
return true;
}

@Override
public boolean isChildSelectable( int groupPosition, int childPosition) {
return true;
}

// 获取某一项的 View 的逻辑
private TextView getGenericView() {
AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, 48);
TextView textView = new TextView(_ExpandableList. this);
textView.setLayoutParams(lp);
textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
textView.setPadding(32, 0, 0, 0);
return textView;
}
}
}
OK
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上接系出名门Android(8) - 控件(View)之TextSwitcher, Gallery, ImageSwitcher, GridView, ListView

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