今天就跟大家聊聊有關(guān)Android 開(kāi)發(fā)中怎么利用TreeView實(shí)現(xiàn)一個(gè)多級(jí)樹(shù)形列表,可能很多人都不太了解,為了讓大家更加了解,小編給大家總結(jié)了以下內(nèi)容,希望大家根據(jù)這篇文章可以有所收獲。
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具體的實(shí)現(xiàn)思路參考下面的項(xiàng)目結(jié)構(gòu)和具體代碼:
Element.Java:
package com.example.androidtreeviewdemo.treeview; /** * Element類 * @author carrey * */ public class Element { /** 文字內(nèi)容 */ private String contentText; /** 在tree中的層級(jí) */ private int level; /** 元素的id */ private int id; /** 父元素的id */ private int parendId; /** 是否有子元素 */ private boolean hasChildren; /** item是否展開(kāi) */ private boolean isExpanded; /** 表示該節(jié)點(diǎn)沒(méi)有父元素,也就是level為0的節(jié)點(diǎn) */ public static final int NO_PARENT = -1; /** 表示該元素位于最頂層的層級(jí) */ public static final int TOP_LEVEL = 0; public Element(String contentText, int level, int id, int parendId, boolean hasChildren, boolean isExpanded) { super(); this.contentText = contentText; this.level = level; this.id = id; this.parendId = parendId; this.hasChildren = hasChildren; this.isExpanded = isExpanded; } public boolean isExpanded() { return isExpanded; } public void setExpanded(boolean isExpanded) { this.isExpanded = isExpanded; } public String getContentText() { return contentText; } public void setContentText(String contentText) { this.contentText = contentText; } public int getLevel() { return level; } public void setLevel(int level) { this.level = level; } public int getId() { return id; } public void setId(int id) { this.id = id; } public int getParendId() { return parendId; } public void setParendId(int parendId) { this.parendId = parendId; } public boolean isHasChildren() { return hasChildren; } public void setHasChildren(boolean hasChildren) { this.hasChildren = hasChildren; } }
TreeViewAdapter.java:
package com.example.androidtreeviewdemo.treeview; import java.util.ArrayList; import com.example.androidtreeviewdemo.R; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.TextView; /** * TreeViewAdapter * @author carrey * */ public class TreeViewAdapter extends BaseAdapter { /** 元素?cái)?shù)據(jù)源 */ private ArrayList<Element> elementsData; /** 樹(shù)中元素 */ private ArrayList<Element> elements; /** LayoutInflater */ private LayoutInflater inflater; /** item的行首縮進(jìn)基數(shù) */ private int indentionBase; public TreeViewAdapter(ArrayList<Element> elements, ArrayList<Element> elementsData, LayoutInflater inflater) { this.elements = elements; this.elementsData = elementsData; this.inflater = inflater; indentionBase = 50; } public ArrayList<Element> getElements() { return elements; } public ArrayList<Element> getElementsData() { return elementsData; } @Override public int getCount() { return elements.size(); } @Override public Object getItem(int position) { return elements.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder = null; if (convertView == null) { holder = new ViewHolder(); convertView = inflater.inflate(R.layout.treeview_item, null); holder.disclosureImg = (ImageView) convertView.findViewById(R.id.disclosureImg); holder.contentText = (TextView) convertView.findViewById(R.id.contentText); convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } Element element = elements.get(position); int level = element.getLevel(); holder.disclosureImg.setPadding( indentionBase * (level + 1), holder.disclosureImg.getPaddingTop(), holder.disclosureImg.getPaddingRight(), holder.disclosureImg.getPaddingBottom()); holder.contentText.setText(element.getContentText()); if (element.isHasChildren() && !element.isExpanded()) { holder.disclosureImg.setImageResource(R.drawable.close); //這里要主動(dòng)設(shè)置一下icon可見(jiàn),因?yàn)閏onvertView有可能是重用了"設(shè)置了不可見(jiàn)"的view,下同。 holder.disclosureImg.setVisibility(View.VISIBLE); } else if (element.isHasChildren() && element.isExpanded()) { holder.disclosureImg.setImageResource(R.drawable.open); holder.disclosureImg.setVisibility(View.VISIBLE); } else if (!element.isHasChildren()) { holder.disclosureImg.setImageResource(R.drawable.close); holder.disclosureImg.setVisibility(View.INVISIBLE); } return convertView; } /** * 優(yōu)化Holder * @author carrey * */ static class ViewHolder{ ImageView disclosureImg; TextView contentText; } }
TreeViewItemClickListener.java:
package com.example.androidtreeviewdemo.treeview; import java.util.ArrayList; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; /** * TreeView item點(diǎn)擊事件 * @author carrey * */ public class TreeViewItemClickListener implements OnItemClickListener { /** adapter */ private TreeViewAdapter treeViewAdapter; public TreeViewItemClickListener(TreeViewAdapter treeViewAdapter) { this.treeViewAdapter = treeViewAdapter; } @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { //點(diǎn)擊的item代表的元素 Element element = (Element) treeViewAdapter.getItem(position); //樹(shù)中的元素 ArrayList<Element> elements = treeViewAdapter.getElements(); //元素的數(shù)據(jù)源 ArrayList<Element> elementsData = treeViewAdapter.getElementsData(); //點(diǎn)擊沒(méi)有子項(xiàng)的item直接返回 if (!element.isHasChildren()) { return; } if (element.isExpanded()) { element.setExpanded(false); //刪除節(jié)點(diǎn)內(nèi)部對(duì)應(yīng)子節(jié)點(diǎn)數(shù)據(jù),包括子節(jié)點(diǎn)的子節(jié)點(diǎn)... ArrayList<Element> elementsToDel = new ArrayList<Element>(); for (int i = position + 1; i < elements.size(); i++) { if (element.getLevel() >= elements.get(i).getLevel()) break; elementsToDel.add(elements.get(i)); } elements.removeAll(elementsToDel); treeViewAdapter.notifyDataSetChanged(); } else { element.setExpanded(true); //從數(shù)據(jù)源中提取子節(jié)點(diǎn)數(shù)據(jù)添加進(jìn)樹(shù),注意這里只是添加了下一級(jí)子節(jié)點(diǎn),為了簡(jiǎn)化邏輯 int i = 1;//注意這里的計(jì)數(shù)器放在for外面才能保證計(jì)數(shù)有效 for (Element e : elementsData) { if (e.getParendId() == element.getId()) { e.setExpanded(false); elements.add(position + i, e); i ++; } } treeViewAdapter.notifyDataSetChanged(); } } }
MainActivity.java:
package com.example.androidtreeviewdemo; import java.util.ArrayList; import com.example.androidtreeviewdemo.treeview.Element; import com.example.androidtreeviewdemo.treeview.TreeViewAdapter; import com.example.androidtreeviewdemo.treeview.TreeViewItemClickListener; import android.os.Bundle; import android.app.Activity; import android.content.Context; import android.view.LayoutInflater; import android.view.Menu; import android.widget.ListView; public class MainActivity extends Activity { /** 樹(shù)中的元素集合 */ private ArrayList<Element> elements; /** 數(shù)據(jù)源元素集合 */ private ArrayList<Element> elementsData; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); init(); ListView treeview = (ListView) findViewById(R.id.treeview); TreeViewAdapter treeViewAdapter = new TreeViewAdapter( elements, elementsData, inflater); TreeViewItemClickListener treeViewItemClickListener = new TreeViewItemClickListener(treeViewAdapter); treeview.setAdapter(treeViewAdapter); treeview.setOnItemClickListener(treeViewItemClickListener); } private void init() { elements = new ArrayList<Element>(); elementsData = new ArrayList<Element>(); //添加節(jié)點(diǎn) -- 節(jié)點(diǎn)名稱,節(jié)點(diǎn)level,節(jié)點(diǎn)id,父節(jié)點(diǎn)id,是否有子節(jié)點(diǎn),是否展開(kāi) //添加最外層節(jié)點(diǎn) Element e1 = new Element("山東省", Element.TOP_LEVEL, 0, Element.NO_PARENT, true, false); //添加第一層節(jié)點(diǎn) Element e2 = new Element("青島市", Element.TOP_LEVEL + 1, 1, e1.getId(), true, false); //添加第二層節(jié)點(diǎn) Element e3 = new Element("市南區(qū)", Element.TOP_LEVEL + 2, 2, e2.getId(), true, false); //添加第三層節(jié)點(diǎn) Element e4 = new Element("香港中路", Element.TOP_LEVEL + 3, 3, e3.getId(), false, false); //添加第一層節(jié)點(diǎn) Element e5 = new Element("煙臺(tái)市", Element.TOP_LEVEL + 1, 4, e1.getId(), true, false); //添加第二層節(jié)點(diǎn) Element e6 = new Element("芝罘區(qū)", Element.TOP_LEVEL + 2, 5, e5.getId(), true, false); //添加第三層節(jié)點(diǎn) Element e7 = new Element("鳳凰臺(tái)街道", Element.TOP_LEVEL + 3, 6, e6.getId(), false, false); //添加第一層節(jié)點(diǎn) Element e8 = new Element("威海市", Element.TOP_LEVEL + 1, 7, e1.getId(), false, false); //添加最外層節(jié)點(diǎn) Element e9 = new Element("廣東省", Element.TOP_LEVEL, 8, Element.NO_PARENT, true, false); //添加第一層節(jié)點(diǎn) Element e10 = new Element("深圳市", Element.TOP_LEVEL + 1, 9, e9.getId(), true, false); //添加第二層節(jié)點(diǎn) Element e11 = new Element("南山區(qū)", Element.TOP_LEVEL + 2, 10, e10.getId(), true, false); //添加第三層節(jié)點(diǎn) Element e12 = new Element("深南大道", Element.TOP_LEVEL + 3, 11, e11.getId(), true, false); //添加第四層節(jié)點(diǎn) Element e13 = new Element("10000號(hào)", Element.TOP_LEVEL + 4, 12, e12.getId(), false, false); //添加初始樹(shù)元素 elements.add(e1); elements.add(e9); //創(chuàng)建數(shù)據(jù)源 elementsData.add(e1); elementsData.add(e2); elementsData.add(e3); elementsData.add(e4); elementsData.add(e5); elementsData.add(e6); elementsData.add(e7); elementsData.add(e8); elementsData.add(e9); elementsData.add(e10); elementsData.add(e11); elementsData.add(e12); elementsData.add(e13); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.activity_main, menu); return true; } }
treeview_item.xml:
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" > <ImageView android:id="@+id/disclosureImg" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerVertical="true" android:layout_alignParentLeft="true"/> <TextView android:id="@+id/contentText" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerVertical="true" android:layout_toRightOf="@id/disclosureImg"/> </RelativeLayout>
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="@+id/treeview" android:layout_width="match_parent" android:layout_height="match_parent"/> </RelativeLayout>
看完上述內(nèi)容,你們對(duì)Android 開(kāi)發(fā)中怎么利用TreeView實(shí)現(xiàn)一個(gè)多級(jí)樹(shù)形列表有進(jìn)一步的了解嗎?如果還想了解更多知識(shí)或者相關(guān)內(nèi)容,請(qǐng)關(guān)注創(chuàng)新互聯(lián)行業(yè)資訊頻道,感謝大家的支持。
本文標(biāo)題:Android開(kāi)發(fā)中怎么利用TreeView實(shí)現(xiàn)一個(gè)多級(jí)樹(shù)形列表
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