Android中的Spinner未选择位置0

时间：2015-07-11 09:31:16

标签： android android-spinner

我创建了一个有三个项目的微调器

每日

每周

每月

我在我的java文件中执行了以下操作：

navSpinner = new ArrayList<SpinnerNavItem>();
        navSpinner.add(new SpinnerNavItem(getResources().getString(R.string.dailyview)));
        navSpinner.add(new SpinnerNavItem(getResources().getString(R.string.weekview)));
        navSpinner.add(new SpinnerNavItem(getResources().getString(R.string.monthview)));

        adapter = new TitleNavigationAdapter(getActivity().getApplicationContext(), navSpinner);
        mSpinner = (Spinner) rootView.findViewById(R.id.spinner);
        mSpinner.setAdapter(adapter);
        mSpinner.setOnItemSelectedListener(this);

OnItemSelected方法（Implements AdapterView.OnItemSelectedListener）

public void onItemSelected(AdapterView<?> parentView, View v, int position, long id) {

        Log.e("Position", "= " + position);

        if (mNaviFirstHit)
        {
            mNaviFirstHit = false;
        }
        else
        {

            Fragment fragment = null;
            switch (position) {
                case 0:

                    Log.e("Week", "= " + position);
                    break;

                case 1:

                    backspace = 1;

                    Log.e("Week", "= " + position);

                    break;

                case 2:

                    backspace = 1;

                    Log.e("Week", "= " + position);

                    break;

                default:
                    break;
            }
        }
    }

    public void onNothingSelected(AdapterView<?> parentView) {

    }

适配器：

public class TitleNavigationAdapter extends BaseAdapter 
{
    private TextView txtTitle;
    private ArrayList<SpinnerNavItem> spinnerNavItem;
    private Context context;
    private TextView txtHeading;
    private SharedPreferences pref;

    public TitleNavigationAdapter(Context context, ArrayList<SpinnerNavItem> spinnerNavItem) 
    {
        this.spinnerNavItem = spinnerNavItem;
        this.context = context;
    }

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

    @Override
    public Object getItem(int index) 
    {
        return spinnerNavItem.get(index);
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) 
    { 
        if (convertView == null) 
        {
            LayoutInflater mInflater = (LayoutInflater)
                    context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
            convertView = mInflater.inflate(R.layout.list_item_title, null);
        }

        txtTitle = (TextView) convertView.findViewById(R.id.txtTitle);
        txtTitle.setText(spinnerNavItem.get(position).getTitle());

        txtTitle.setTextColor(context.getResources().getColor(R.color.orangeText));
        txtTitle.setTextSize(TypedValue.COMPLEX_UNIT_SP, 12);

        pref = context.getSharedPreferences("MyPref", Context.MODE_PRIVATE);
        String text = pref.getString("selectedItem", context.getResources().getString(R.string.transaction_main_gridview));

        if (text.equalsIgnoreCase(convertView.getResources().getString(R.string.transaction_main_gridview)))
        {
            txtTitle.setText(convertView.getResources().getString(R.string.transaction_main_gridview_text));
        }
        else if (text.equalsIgnoreCase(convertView.getResources().getString(R.string.transaction_main_weekview)))
        {
            txtTitle.setText(convertView.getResources().getString(R.string.transaction_main_weekly_text));
        }
        else if (text.equalsIgnoreCase(convertView.getResources().getString(R.string.transaction_main_monthview)))
        {
            txtTitle.setText(convertView.getResources().getString(R.string.transaction_main_monthly_text));
        }

        return convertView;
    }


    @Override
    public View getDropDownView(int position, View convertView, ViewGroup parent) 
    {
        if (convertView == null) 
        {
            LayoutInflater mInflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
            convertView = mInflater.inflate(R.layout.list_item_title, null);
        }

        txtTitle = (TextView) convertView.findViewById(R.id.txtTitle);
        txtTitle.setPadding(20, 20, 0, 20);

        txtHeading = (TextView) convertView.findViewById(R.id.txtheading);
        txtHeading.setVisibility(View.GONE);

        txtTitle.setText(spinnerNavItem.get(position).getTitle());
        return convertView;
    }

}

当我选择位置1或2（我正确地获取日志）时，上面的代码工作正常，然后从位置1或2，如果我选择位置0，则根本不打印日志。位置不会被调用。即使只是位置记录也没有打印出来。

这真的很奇怪我不确定为什么会这样？有人可以帮我吗？

谢谢！

5 个答案:

答案 0 :(得分：1)

如果要在片段中创建微调器，则必须在Fragment onCreatedView（）中声明它。不在你的FragmentActivity的onCreate（）中。

OnItemSelectedListener如果要在Fragment内的微调器上使用侦听器，则必须在FragmentMain内部而不是在Activity内部实现。

您的代码的这些更改已经过测试。

您的上下文返回null（无论如何，在我的测试代码中）： 

        public class InformationList  extends Activity implements OnItemSelectedListener {
    .....

所以改为：

TitleNavigationAdapter adapter = new TitleNavigationAdapter（this，navSpinner）; //添加了此

您的活动是否实施OnItemSelectedListener？： 

    @Override
public SpinnerNavItem getItem(int index) //SpinnerNavItem from Object
    {
        return spinnerNavItem.get(index);
    }

我也会在TitleNavigationAdapter中更改此内容： 

07-18 19:46:53.468: E/Position(27325): = 0
07-18 19:46:53.468: E/day(27325): = 0
07-18 19:47:04.487: E/Position(27325): = 1
07-18 19:47:04.488: E/Week(27325): = 1
07-18 19:47:06.426: E/Position(27325): = 2
07-18 19:47:06.426: E/month(27325): = 2

<强>结果： 

RequestHandle

正常运作。

spinner

答案 1 :(得分：0)

首先删除getApplicationContext() 

adapter = new TitleNavigationAdapter(getActivity(), navSpinner);

我认为它会被调用，但是因为你的Log参数not filtering why？而是，所有Log行尝试这个

 Log.e("Position", "= " + String.valueOf(position));

在设置onitemSelectedListener将初始选择重新设置为0后尝试后，看看是否存在显着差异

希望有所帮助

答案 2 :(得分：0)

此代码也有效： 

    //inflate  
    View rootView = this.findViewById(android.R.id.content);
    setContentView(R.layout.list_item_title);

        navSpinner = new ArrayList<SpinnerNavItem>();
        navSpinner.add(new SpinnerNavItem(getResources().getString(R.string.dailyview)));
        navSpinner.add(new SpinnerNavItem(getResources().getString(R.string.weekview)));
        navSpinner.add(new SpinnerNavItem(getResources().getString(R.string.monthview)));

        if(navSpinner != null  && navSpinner.size() > 0)
        {
//          Context mContext = getActivity().getApplicationContext();//jrg returns null !
            TitleNavigationAdapter adapter = new TitleNavigationAdapter(this, android.R.layout.simple_spinner_item, navSpinner);//jrg

            adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);//
            Spinner mSpinner = (Spinner) rootView.findViewById(R.id.spinner);       
            mSpinner.setAdapter(adapter);
            mSpinner.setOnItemSelectedListener(this);
        }
    }//OnCreate
TitleNavigationAdapter

中的

    public class TitleNavigationAdapter extends ArrayAdapter<SpinnerNavItem> 
    {

        public TitleNavigationAdapter(Context context,int resource ,ArrayList<SpinnerNavItem> navSpinner) 
        {
             super(context, resource , navSpinner);//jrg
            this.spinnerNavItem = navSpinner;
            this.context = context;
        }

    .....

    @Override
    public void registerDataSetObserver(DataSetObserver observer) {
        // TODO Auto-generated method stub

    }
    @Override
    public void unregisterDataSetObserver(DataSetObserver observer) {
        // TODO Auto-generated method stub

    }
    @Override
    public boolean hasStableIds() {
        // TODO Auto-generated method stub
        return false;
    }
    @Override
    public int getItemViewType(int position) {
        // TODO Auto-generated method stub
        return 0;
    }
    @Override
    public int getViewTypeCount() {
        // TODO Auto-generated method stub
        return 0;
    }
    @Override
    public boolean isEmpty() {
        // TODO Auto-generated method stub
        return false;
    }

    }

<强> SpinnerNavItem：

公共类SpinnerNavItem {

private String title;
private int icon;

public SpinnerNavItem(String title, int icon)
{
    this.title = title;
    this.icon = icon;
}

public SpinnerNavItem(String title)
{
    this.title = title;

// this.icon = icon;     } 

public String getTitle()
{
    return this.title;
}

public int getIcon()
{
    return this.icon;
}

}

** list_item_title.xml ** 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
        <TextView
        android:text="Title"
        android:id="@+id/txtTitle"
        android:layout_marginTop="20dp"
        android:layout_marginBottom="20dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:text="Choose Time"
        android:id="@+id/txtheading"
        android:layout_marginTop="20dp"
        android:layout_marginBottom="20dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Spinner
        android:id="@+id/spinner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    </Spinner>
</LinearLayout>

答案 3 :(得分：0)

 navSpinner = new ArrayList<SpinnerNavItem>();
        navSpinner.add(new SpinnerNavItem(getResources().getString(R.string.dailyview)));
        navSpinner.add(new SpinnerNavItem(getResources().getString(R.string.weekview)));
        navSpinner.add(new SpinnerNavItem(getResources().getString(R.string.monthview)));

adapter = new TitleNavigationAdapter（getActivity（）。getApplicationContext（），navSpinner）;

以上代码行是调用适配器的正确方法

好像你在任何你应该调用的Activity中调用适配器

adapter = new TitleNavigationAdapter(this, navSpinner);
            mSpinner = (Spinner) rootView.findViewById(R.id.spinner);

或

adapter = new TitleNavigationAdapter(YourActivityNAme.this, navSpinner);

否则你从调用这个adpater的地方就像在Fragment或者listView，Gridview等中你所调用的任何地方膨胀你需要传递Context的那个Activity或者那个Activity类引用的布局一边

Context cntxt;//declare in class
  cntxt=getActivity()//in  oncreate() in case or fragment
cntxt=context;//by passing the Activity reference in the constructor  of YourClassName class

context是在YourClassName(Context context ,...other parameters){....}

之类的构造函数中传递的值 
 adapter = new TitleNavigationAdapter(cntxt, navSpinner);
                mSpinner = (Spinner) rootView.findViewById(R.id.spinner);
                mSpinner.setAdapter(adapter);
                mSpinner.setOnItemSelectedListener(this);

在这里你也在setOnItemSelectedListener中使用它，所以你需要在同一个类中提供这个监听器的实现，你在这里引用了这个  public class YourClassName extends YourExtendsClassName implements OnItemSelectedListener {......}以及上面的所有代码都在此类内部，或者您休息与此类相关的代码 或者你可以这样做

 mSpinner.setOnItemSelectedListener(new OnItemSelectedListener()
        {

        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
        {
            Log.e("Position", "= " + position);

            if (mNaviFirstHit)
            {
            mNaviFirstHit = false;
            }
            else
            {

                Fragment fragment = null;
                switch (position) {
                    case 0:

                        Log.e("Week", "= " + position);
                        break;

                    case 1:

                        backspace = 1;

                        Log.e("Week", "= " + position);

                        break;

                    case 2:

                        backspace = 1;

                        Log.e("Week", "= " + position);

                        break;

                    default:
                        break;
                }
            }

        }

        @Override
        public void onNothingSelected(AdapterView<?> parent)
        {
            // TODO Auto-generated method stub

        }});

并且您还需要修改更安全的一面 你还应该在TitleNavigationAdapter中更改它：

 @Override
public SpinnerNavItem getItem(int index) //SpinnerNavItem from Object
    {
        return spinnerNavItem.get(index);
    }

并且您的代码也将针对位置0元素运行 另请检查您在public void onItemSelected(AdapterView<?> parent, View view, int position, long id){...}中编写的逻辑 和  如果您需要真正的帮助，请提供完整的信息 而不是破碎的代码

现在你可以看到位置0的日志

答案 4 :(得分：0)

spbBloodGrp.setOnItemSelectedListener（new AdapterView.OnItemSelectedListener（）{             String bloodgroup =＆＃34;＆＃34 ;; 

        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long id) {
            // TODO Auto-generated method stub
            //String bloodgroup = spbBloodGrp.getSelectedItem().toString();
            if (position != 0) {
                bloodgroup = spbBloodGrp.getSelectedItem().toString();
            }
            // Toast.makeText(getBaseContext(), bloodgroup, Toast.LENGTH_SHORT).show();
            etxtbloodGrp.setText(bloodgroup);
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub
        }
    });

它会帮助你，祝你好运

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