Question

我想点击Dialog行时打开ListView，并从Spinner加载SQLiteDatabase的数据。

填写Spinner时，应用程序强制关闭。崩溃就在这一行：

spinner.setAdapter（DataAdapter的）;

DBAdapter.java

 public List<String> getAllLabels() {
        List<String> labels = new ArrayList<String>();

        // Select All Query
        String selectQuery = "SELECT  * FROM " + DATABASE_MAINTABLE;

        SQLiteDatabase db = DBHelper.getReadableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);

        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                labels.add(cursor.getString(1));
            } while (cursor.moveToNext());
        }

        // closing connection
        cursor.close();
        db.close();

        // returning lables

        return labels;
    }

MSmsActivity.java

 public void passengerInformationPopup() {
        final Dialog dialog = new Dialog(MSmsActivity.this);

        dialog.setContentView(R.layout.activity_dialog);
        loadSpinnerData(); //{"Mr.","Mrs.","Ms"};
        //   String []  tittleSpinner = {"Mr.","Mrs.","Ms"};
        //  Spinner tittleSpinner = (Spinner) dialog.findViewById(R.id.spinner);
//        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,
//                android.R.layout.simple_spinner_item, tittleSpinner);

        // dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_item);
        // tittleSpinner.setAdapter(dataAdapter);
        dialog.show();
    }

    private void loadSpinnerData() {
        // DatabaseHandler db = new DatabaseHandler(getApplicationContext());
        Spinner spinner = (Spinner) findViewById(R.id.spinner);
        // Spinner Drop down elements
        List<String> lables = db.getAllLabels();

        // Creating adapter for spinner
        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, lables);

        // Drop down layout style - list view with radio button
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        // attaching data adapter to spinner
        spinner.setAdapter(dataAdapter);
    }

错误

E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.NullPointerException
at www.project_category.ir.project_category.MSmsActivity.loadSpinnerData(MSmsActivity.java:301)
at www.project_category.ir.project_category.MSmsActivity.passengerInformationPopup(MSmsActivity.java:276)
at www.project_category.ir.project_category.MSmsActivity$2.onItemClick(MSmsActivity.java:176)
at android.widget.AdapterView.performItemClick(AdapterView.java:301)
at android.widget.AbsListView.performItemClick(AbsListView.java:1507)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3336)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:177)
at android.app.ActivityThread.main(ActivityThread.java:5493)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1225)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1041)
at dalvik.system.NativeStart.main(Native Method)

Answer 1

如果你的微调器在对话框内，那么很可能你的微调器id为null。尝试找到这样的id和popup方法

spinner=dialog.findViewById(R.id.spinner);

Answer 2

Spinner位于R.layout.activity_dialog，这是Dialog的布局。

您需要使用

Spinner spinner=dialog.findViewById(R.id.spinner);

从db中单击时打开自定义对话框时填充微调器

2 个答案: