android – 如何使用SimpleAdapter从Spinner获取选定的项目位置

概述我有一个微调器,使用下面的代码填充,我想让用户从微调器中选择项目. 最好的方法是什么？ List<Map<String, String>> tablelist = new ArrayList<>(); SQLiteDatabase db = openOrCreateDatabase("database", MODE_PRIVATE, null); String query = " 我有一个微调器,使用下面的代码填充,我想让用户从微调器中选择项目.
最好的方法是什么？

List<Map<String,String>> tableList  = new ArrayList<>();    sqliteDatabase db = openorCreateDatabase("database",MODE_PRIVATE,null);    String query = "select * from table";    Cursor ps = db.rawquery(query,null);    while (ps.movetoNext()){        Map<String,String> datanum = new HashMap<>();        datanum.put("ID",ps.getString(ps.getColumnIndex("ID")));        datanum.put("Some",ps.getString(ps.getColumnIndex("Some")));        tableList.add(datanum);    }    db.close();    ps.close();    SimpleAdapter spinnerAdapter = new SimpleAdapter(this,tableList,R.layout.row_spinner,new String[] {"ID","Some"},new int[] {androID.R.ID.text1,androID.R.ID.text1});    spinnerAdapter.notifyDataSetChanged();    spinnerAdapter.setDropDownVIEwResource(R.layout.row_spinner_List);    spinner.setAdapter(spinnerAdapter);

解决方法 我将回答这个问题：“获取setSelection()方法所需项目位置的最佳方法”我希望这是你所要求的.

我用ArrayAdapter更改了SimpleAdapter.

我首选为每个结果创建一个对象,因为你是DTB请求,并将对象映射到微调器.因此,您可以轻松访问每个结果.

像这样 ：

public class test {    private String TAG = "test";    private Activity curAct;    private Spinner spinner;    private SpnObj[] spinnerOptions;    public test(Activity curAct) {        this.curAct = curAct;    }    public voID test() {        this.spinner = new Spinner(this.curAct);        this.spinnerOptions = this.getSpnContent();        final ArrayAdapter spinnerAdapter = new ArrayAdapter<>(this.curAct,androID.R.layout.simple_spinner_item,spinnerOptions);        spinnerAdapter.setDropDownVIEwResource(androID.R.layout.simple_spinner_dropdown_item);        this.spinner.setAdapter(spinnerAdapter);        // setSelection with item ID = 1        this.preSelectItem(1);        // setSelection with item some = 'some'        this.preSelectItem("some");        // get selectedItem        SpnObj selectedItem = this.getSelectedItem();        Log.d(TAG,"the current selected item ID is : " + selectedItem.ID);        Log.d(TAG,"the current selected item some is : " + selectedItem.some);    }    // this method should be used when you need to access on you're selectedItem    public SpnObj getSelectedItem() {        return (SpnObj) this.spinner.getSelectedItem();    }    // this method should be used for set the selection on a item with the ID => maybe that was what you're asking for    public voID preSelectItem(int ID) {        boolean doWeStopTheLoop = false;        for (int i = 0; i < this.spinnerOptions.length && !doWeStopTheLoop; i++) {            if (((SpnObj) this.spinner.getItemAtposition(i)).ID == ID) {                this.spinner.setSelection(i);                doWeStopTheLoop = true; //you can use break; too            }        }    }    // this method should be used for set the selection on a item with the ID => maybe that was what you're asking for    // surcharge for 'some' column    public voID preSelectItem(String some) {        boolean doWeStopTheLoop = false;        for (int i = 0; i < this.spinnerOptions.length && !doWeStopTheLoop; i++) {            if (((SpnObj) this.spinner.getItemAtposition(i)).some.equals(some)) {                this.spinner.setSelection(i);                doWeStopTheLoop = true; //you can use break; too            }        }    }    private SpnObj[] getSpnContent() {      // this method must be call in a thread        sqliteDatabase db = this.curAct.openorCreateDatabase("database",null);        String query = "select * from table";        Cursor ps = db.rawquery(query,null);        SpnObj[] spnContent = new SpnObj[ps.getColumnCount()];        if (ps.getColumnCount() > 0) {            int iterator = 0;            while (ps.movetoNext()) {                spnContent[iterator] = new SpnObj(                        ps.getInt(ps.getColumnIndex("ID")),ps.getString(ps.getColumnIndex("Some"))                );                iterator++;            }        } else {            // no rows : insert code here if you want manage this        }        db.close();        ps.close();        return spnContent;    }}// this object is only encapsulate the DTB result in a java class,so we can work easily withclass SpnObj {    public int ID;    public String some;    public SpnObj(int ID,String some) {        this.ID = ID;        this.some = some;    }    @OverrIDe    public String toString() {          // important ! this method will be used for display the value in the dropdown List from the spinner        return this.some;    }}

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