android下拉五级菜单联动

张泽旭

发布于 2018-12-10 16:42:10

2.5K0

发布于 2018-12-10 16:42:10

文章被收录于专栏：张泽旭的专栏

android下拉五级菜单联动

一、问题引出

本人是一个不擅长Android的开发的，但是这几天在做联通的一个服务器配件管理系统，做完B/S的又要写C/S的，老板要求没办法。在做的过程中遇到了一个下拉菜单联动的问题，以前没做过，突然做还真有点不知所措了，在网上找了一大堆发现数据都是本地的应该构造好了，没卵用，不过也给了我很多想发，一开始想到用树去解决，可是每个树的节点个数不知道，要是动态创建就会很麻烦。最后在自己的努力下来构造JSON数据格式，其实弄明白感觉很简单，就是并保存你的上一级是谁，你的下一级是谁就可以了，但是数据库做的表没有结构可言很难构造出来有用的数据结构。

二、实例代码

数据库建表如下：

factory 下有多个 type ,这里有一点需要注意，不是 type 下有多个 products_name 而是，factory 和 type 要共同确定有那些 products_name , 好了就这样一次类推，顺序分别是 factory、type 、products_name 、 products_no 、 function . 由此得到的数据库查询语句有： select factory from bjlt_products_type group by factory ;

select type from bjlt_products_type where factory=#{0} group by type;

select products_name from bjlt_products_type where factory=#{0} and type=#{1} group by products_name;

select products_no from bjlt_products_type where factory=#{0} and type=#{1} and products_name=#{2} group by products_no;

select function from bjlt_products_type where factory=#{0} and type=#{1} and products_name=#{2} and products_no=#{3} group by function;

知道Mybatis的很容易看懂，我这里就不说了; 查询数据结构构造json数据代码

java后端数据代码

@ResponseBody
    @RequestMapping("/user_info/requestproductstypeApplication.html")
    public String user_infoProductsFactory(HttpServletRequest request, HttpServletResponse response)
            throws IOException {
        List<String> str_1 = bjlt_products_typeService.factory();
        String str1 = "";
        String str2 = "";
        String str3 = "";
        String str4 = "";
        String str5 = "";
        Json json = new Json();
        for (int i = 0; i < str_1.size(); i++) {
            str1 = str1 + str_1.get(i) + "$$";
			List<String> str_2 = bjlt_products_typeService.type(str_1.get(i));
			str2 = "";
			for (int j = 0; j < str_2.size(); j++) {
				str2 = str2 + str_2.get(j) + "$$";
                List<String> str_3 = bjlt_products_typeService.products_name(str_1.get(i), str_2.get(j));
                str3 = "";
                for (int z = 0; z < str_3.size(); z++) {

                    str3 = str3 + str_3.get(z) + "$$";
					List<String> str_4 = bjlt_products_typeService.products_no(str_1.get(i), str_2.get(j),
							str_3.get(z));
					str4 = "";
					for (int q = 0; q < str_4.size(); q++) {
						str4 = str4 + str_4.get(q) + "$$";
						List<String> str_5 = bjlt_products_typeService.function(str_1.get(i), str_2.get(j),
								str_3.get(z), str_4.get(q));
						str5 = "";
						for (int k = 0; k < str_5.size(); k++) {
							str5 = str5 + str_5.get(k) + "$$";
						}
						json.add(str_1.get(i) + "$$" + str_2.get(j) + "$$" + str_3.get(z) + "$$" + str_4.get(q), str5);
					}
					json.add(str_1.get(i) + "$$" + str_2.get(j) + "$$" + str_3.get(z), str4);
				}
				json.add(str_1.get(i) + "$$" + str_2.get(j), str3);
            }
            json.add(str_1.get(i), str2);
        }
        json.add("factory", str1);
        json.add("result", "ok");
        System.out.println(json.toString());
        // response.addHeader("Access-Control-Allow-Origin",
        // "http://127.0.0.1:8020");
        return json.toString();
    }

此代码是循环获取每个类别的数据，主要思想为键值保存他的父亲，值保存他下面的儿子，举个例子

{"华为": "BBU$$RRU$$"}//代表华为下有两个类别，到时候value可以直接用split取出字符数组
{"华为$$RRU": "RRU3775$$RRU3959$$"}//当有了华为下的儿子，就可以和儿子组合起来和成一个唯一的键，为一个字符串//
下面是获取到的整个JSON字符串
String str = {  "爱立信$$BBU$$DUS4102": "KDU137624/11$$",
				"华为$$RRU$$RRU3959$$WD5MIRUYC10E": "基带板$$",
				"factory": "华为$$爱立信$$",
				"华为": "BBU$$RRU$$",
				"爱立信$$BBU$$DUS4102$$KDU137624/11": "基带板$$",
				"华为$$BBU": "UMPTb2$$",
				"华为$$RRU": "RRU3775$$RRU3959$$",
				"华为$$RRU$$RRU3959": "WD5MIRUYC10E$$",
				"华为$$BBU$$UMPTb2": "WD22UMPTb2$$",
				"华为$$RRU$$RRU3775$$D5MPRUC19BC": "电源模块$$",
				"result": "ok",
				"华为$$BBU$$UMPTb2$$WD22UMPTb2": "射频单元$$",
				"华为$$RRU$$RRU3775": "D5MPRUC19BC$$",
				"爱立信$$BBU": "DUS4102$$",
				"爱立信$$RRU": "RRUS01B1$$",
				"爱立信$$RRU$$RRUS01B1": "KRC161255/2$$",
				"爱立信$$RRU$$RRUS01B1$$KRC161255/2": "电源模块$$",
				"爱立信": "BBU$$RRU$$"};

和android交互会出现乱码问题，大家可以使用URL编码进行编解码，在最后返回字符串的时候，加入一下代码

UrlUtil.getURLEncoderString(json.toString());//为自己的编码类

Android客户端代码

public class Main2Activity extends AppCompatActivity {
    //下拉组件
    private Spinner factorySpinner = null;   //厂商
    private Spinner typeSpinner = null;  //大类
    private Spinner products_nameSpinner = null;     //产品名称
    private Spinner products_noSpinner = null;    //产品号
    private Spinner functionSpinner = null;    //产品号
    //数据适配器
    ArrayAdapter<String> factoryAdapter = null;//
    ArrayAdapter<String> typeAdapter = null;  //
    ArrayAdapter<String> products_nameAdapter = null;    //
    ArrayAdapter<String> products_noAdapter = null;    //
    ArrayAdapter<String> functionAdapter = null;    //
    JSONObject root = null;
    static int provincePosition = 3;
    HttpClient client;
    //
    private String[] text = new String[]{"请选择"};
    private String[] factory_1 = null;
    ProgressDialog waitingDialog=null;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        waitingDialog= new ProgressDialog(Main2Activity.this);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        client = new DefaultHttpClient();
        readNet(Contents.HOST+"user_info/requestproductstypeApplication.html");
        showWaitingDialog();
    }

    private void showWaitingDialog() {
        waitingDialog.setTitle("我是一个等待Dialog");
        waitingDialog.setMessage("等待中...");
        waitingDialog.setIndeterminate(true);
        waitingDialog.setCancelable(false);
        waitingDialog.show();
    }
    /*
     * 设置下拉框，默认的值，内容为请选择
     */
    private void setSpinner()
    {
        factorySpinner = (Spinner)findViewById(R.id.spin_factory);
        typeSpinner = (Spinner)findViewById(R.id.spin_type);
        products_nameSpinner = (Spinner)findViewById(R.id.spin_products_name);
        products_noSpinner = (Spinner)findViewById(R.id.spin_products_no);
        functionSpinner = (Spinner)findViewById(R.id.spin_function);

        //绑定适配器和值
        try{
            System.out.println(root.getString("factory").split("\\$\\$")[0]);
            factoryAdapter = new ArrayAdapter<String>(Main2Activity.this,
                    android.R.layout.simple_spinner_item, factory_1);
        }catch (Exception e){
          e.printStackTrace();
        }

        factorySpinner.setAdapter(factoryAdapter);
        factorySpinner.setSelection(0,true);  //设置默认选中项，此处为默认选中第4个值


        typeAdapter = new ArrayAdapter<String>(Main2Activity.this,
                android.R.layout.simple_spinner_item, text);
        typeSpinner.setAdapter(typeAdapter);
        typeSpinner.setSelection(0,true);  //默认选中第0个



        products_nameAdapter = new ArrayAdapter<String>(Main2Activity.this,
                android.R.layout.simple_spinner_item, text);
        products_nameSpinner.setAdapter(products_nameAdapter);
        products_nameSpinner.setSelection(0, true);


        products_noAdapter = new ArrayAdapter<String>(Main2Activity.this,
                android.R.layout.simple_spinner_item, text);
        products_noSpinner.setAdapter(products_noAdapter);
        products_noSpinner.setSelection(0, true);


        functionAdapter = new ArrayAdapter<String>(Main2Activity.this,
                android.R.layout.simple_spinner_item, text);
        functionSpinner.setAdapter(functionAdapter);
        functionSpinner.setSelection(0, true);
        //下拉框监听,单开始选中一个值的时候用，就分别设置每个数据适配器的值，因为有先后有顺序，所以要获取上一个的值，才能设置下一个的值

        factorySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener()
        {
            // 表示选项被改变的时候触发此方法，
            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long arg3)
            {
                try {
                    typeAdapter = new ArrayAdapter<String>(Main2Activity.this,
                            android.R.layout.simple_spinner_item, root.getString(factorySpinner.getItemAtPosition(position).toString()).split("\\$\\$"));
                    typeSpinner.setAdapter(typeAdapter);
                }catch (Exception e){
                    e.printStackTrace();
                }

            }
            @Override
            public void onNothingSelected(AdapterView<?> arg0)
            {

            }

        });
        typeSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener()
        {
            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                                       int position, long arg3)
            {
                try {
                    products_nameAdapter = new ArrayAdapter<String>(Main2Activity.this,
                        android.R.layout.simple_spinner_item, root.getString(factorySpinner.getSelectedItem().toString()+
                        "$$"+typeSpinner.getItemAtPosition(position)).split("\\$\\$"));
                    products_nameSpinner.setAdapter(products_nameAdapter);
                }catch (Exception e){
                    e.printStackTrace();
                }


            }
            @Override
            public void onNothingSelected(AdapterView<?> arg0)
            {

            }
        });
        products_nameSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener()
        {
            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                                       int position, long arg3)
            {
                try {
                    products_noAdapter = new ArrayAdapter<String>(Main2Activity.this,
                            android.R.layout.simple_spinner_item, root.getString(factorySpinner.getSelectedItem().toString()+
                            "$$"+typeSpinner.getSelectedItem().toString()+"$$"+
                            products_nameSpinner.getItemAtPosition(position).toString()).split("\\$\\$"));
                    products_noSpinner.setAdapter(products_noAdapter);
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
            @Override
            public void onNothingSelected(AdapterView<?> arg0)
            {

            }
        });
        products_noSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener()
        {
            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                                       int position, long arg3)
            {
                try {
                    functionAdapter = new ArrayAdapter<String>(Main2Activity.this,
                            android.R.layout.simple_spinner_item, root.getString(factorySpinner.getSelectedItem().toString()+
                            "$$"+typeSpinner.getSelectedItem().toString()+"$$"+
                            products_nameSpinner.getSelectedItem().toString()+"$$"+
                            products_noSpinner.getItemAtPosition(position).toString()).split("\\$\\$"));
                    functionSpinner.setAdapter(functionAdapter);
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
            @Override
            public void onNothingSelected(AdapterView<?> arg0)
            {

            }
        });
    }
    public void readNet(String url) {
        AsyncTask<String, Void, String> execute = new AsyncTask<String, Void, String>() {

            @Override
            protected String doInBackground(String... params) {

                String urlString = params[0];
                System.out.println(urlString);
                HttpGet get = new HttpGet(urlString);
                try {
                    HttpResponse response = client.execute(get);

                    String valueString = EntityUtils.toString(response.getEntity());

                    return valueString;
                } catch (ClientProtocolException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                return null;
            }

            @Override

            protected void  onPostExecute (String s) {
                try{
                    synchronized (this){
//最先开始获取顶层的数据，因为他的键值是固定的，在查询的时候不需要条件，我们设置定的为factory；            
System.out.println(UrlUtil.getURLDecoderString(s));
                        root = new JSONObject(UrlUtil.getURLDecoderString(s));
                        String result = root.getString("result");
                        String[] string = root.getString("factory").split("\\$\\$");
                        factory_1 = new String[string.length+1];
                        factory_1[0] = "请选择";
                        for (int i = 1;i<string.length+1;i++){
                            factory_1[i] = string[i-1];
                        }
//不设置其它内容对会获取不到
                        super.onPostExecute(result);
                    }
                }catch (Exception e){
                  e.printStackTrace();
                }finally {
                    waitingDialog.dismiss();
                    setSpinner();
                }
            }
        }.execute(url);

    }
}

android 下拉xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="600dp"
    android:orientation="vertical"
    android:padding="8dp">

    <Spinner
        android:id="@+id/spin_factory"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1" />
    <Spinner
        android:id="@+id/spin_type"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1" />
    <Spinner
        android:id="@+id/spin_products_name"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1" />
    <Spinner
        android:id="@+id/spin_products_no"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1" />
    <Spinner
        android:id="@+id/spin_function"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1" />

</LinearLayout>
    </LinearLayout>

好了，就这么写内容，由于当时数据库的问题，就先只能这样获取数据了，在查询上效率会面一些，但是一般不会分类太多，多的话那就是大的项目了，可以事先就存在redis中，用Zset，键值还是键，值还是值就获取的更快了。，内容有点多，可以先运行试试，看看效果或许可以在必要的时候帮助你一点。有好的解答和疑问可以在下方评论，也可以加我的QQ：1402876003.