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Android支持展开/收缩功能的列表控件
来源:互联网   发布日期:2015-10-02 16:09:40   浏览:2876次  

导读:最近在做一个Rss阅读器,看了下别人做的阅读器中的列表控件可以展开、收缩,我就在网上搜索了一下。下面就我找到的一个小例子,给大家分享一下。ActivityMain .javapackage study.com.android;import android......

最近在做一个Rss阅读器,看了下别人做的阅读器中的列表控件可以展开、收缩,我就在网上搜索了一下。下面就我找到的一个小例子,给大家分享一下。

ActivityMain .java

package study.com.android;

import android.app.ExpandableListActivity;

import android.os.Bundle;

import android.view.ContextMenu;

import android.view.MenuItem;

import android.view.View;

import android.view.ContextMenu.ContextMenuInfo;

import android.widget.ExpandableListAdapter;

import android.widget.ExpandableListView;

import android.widget.TextView;

import android.widget.Toast;

import android.widget.ExpandableListView.ExpandableListContextMenuInfo;

public class ActivityMain extends ExpandableListActivity {

private ExpandableListAdapter mAdapter;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

this.setTitle("ExpandableList");

mAdapter = new MyExpandableListAdapter(this);

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("ContexMenu");

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;

}

return false;

}

}

MyExpandableListAdapter.java

package study.com.android;

import android.content.Context;

import android.view.Gravity;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AbsListView;

import android.widget.BaseExpandableListAdapter;

import android.widget.TextView;

public class MyExpandableListAdapter extends BaseExpandableListAdapter {

private Context mContext;

// 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" }, };

MyExpandableListAdapter(Context context) {

mContext = context;

}

@Override

public Object getChild(int groupPosition, int childPosition) {

// TODO Auto-generated method stub

return children[groupPosition][childPosition];

}

@Override

public long getChildId(int groupPosition, int childPosition) {

// TODO Auto-generated method stub

return childPosition;

}

// 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 int getChildrenCount(int groupPosition) {

// TODO Auto-generated method stub

return children[groupPosition].length;

}

@Override

public Object getGroup(int groupPosition) {

return groups[groupPosition];

}

@Override

public int getGroupCount() {

// TODO Auto-generated method stub

return groups.length;

}

@Override

public long getGroupId(int groupPosition) {

// TODO Auto-generated method stub

return groupPosition;

}

@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() {

// TODO Auto-generated method stub

return true;

}

@Override

public boolean isChildSelectable(int groupPosition, int childPosition) {

// TODO Auto-generated method stub

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(mContext);

textView.setLayoutParams(lp);

textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);

textView.setPadding(32, 0, 0, 0);

return textView;

}

}

运行的结果如下:

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