按钮单击尝试插入 SQLite 后崩溃（代码和 Stacktrace）

Question

您好，我需要在 SQLite 中插入数据方面的帮助，当我单击按钮时，我的应用程序崩溃了......

有人可以检查吗？

SavacDataBaseAdapter.java：

package com.example.yiquishum.savac4k;

import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import android.widget.Toast;

public class SavacDataBaseAdapter {

    SavacDBHelper helper;

    public SavacDataBaseAdapter(Context context){
        helper = new SavacDBHelper(context);
    }

    public long InsertData(String name, String username, String pass, String gen, String state){

        SQLiteDatabase db = helper.getWritableDatabase();

        ContentValues contentValues = new ContentValues();

        contentValues.put(SavacDBHelper.FName, name);
        contentValues.put(SavacDBHelper.Fnameuser, username);
        contentValues.put(SavacDBHelper.FPass, pass);
        contentValues.put(SavacDBHelper.Fgen, gen);
        contentValues.put(SavacDBHelper.Fstate, state);

        long id = db.insert(SavacDBHelper.TABLE_NAME, null, contentValues);

        return id;

    }

    static class SavacDBHelper extends SQLiteOpenHelper {

        private static final String TAG = "BD Savac";

        static final String DATABASE_NAME = "Savac4K";
        static final String TABLE_NAME = "SavacUser";
        static final int DATABASE_VERSION = 2;

    /* Aqui iran las variables que van en el Query */

        static final String FIDuser = "_Id";
        static final String FName = "Nombre";
        static final String Fnameuser = "Usuario";
        static final String FPass = "Contra";
        static final String Fgen = "Gen";
        static final String Fstate = "Estado";

        /**
         * ******************************************
         */

    /* Aqui iran los Querys de la Base de Datos */

        static final String Query1 = "CREATE TABLE " + TABLE_NAME + " (" + FIDuser + " INTEGER PRIMARY KEY AUTOINCREMENT, " + FName + " VARCHAR(255), " + Fnameuser + " F VARCHAR(255), " + FPass + " VARCHAR(255), " + Fgen + " INTEGER, " + Fstate + " VARCHAR(255));";
        static final String DROP_TABLE = "DROP TABLE IF EXIST " + TABLE_NAME;

        /**
         * *****************************************
         */

        public SavacDBHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
            Toast.makeText(context, "Entro a la BD", Toast.LENGTH_LONG).show();
            Log.v(TAG, "Entro a la BD");
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            //Crear la Base de datos osea las Tablas

            db.execSQL(Query1);
            Log.v(TAG, "Se crea la BD");

        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            db.execSQL(DROP_TABLE);
            onCreate(db);

        }
    }
}

Pregistro.java：

package com.example.yiquishum.savac4k;

import android.database.sqlite.SQLiteDatabase;
import android.os.Message;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.Toast;

public class Pregistro extends ActionBarActivity {

    SavacDataBaseAdapter SavacDataBaseAdap;
    // Declaracion de las Variables para insertarlas en la BD

    EditText Rname, Rusername, Rpass;
    Spinner Rgen, Rstate;

    private static final String TAG = "Registro";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_pregistro);

        Spinner state = (Spinner) findViewById(R.id.estado);
        ArrayAdapter adapter = ArrayAdapter.createFromResource(this, R.array.estado,
                android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        state.setAdapter(adapter);

        Spinner sex = (Spinner) findViewById(R.id.genero);
        ArrayAdapter adapter2 = ArrayAdapter.createFromResource(this, R.array.xexo,
                android.R.layout.simple_spinner_item);
        adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        sex.setAdapter(adapter2);

        SavacDataBaseAdap = new SavacDataBaseAdapter(this);

        /* Aquí obtenemos los datos por vía ID */
        Rname = (EditText) findViewById(R.id.nombre);
        Rusername = (EditText) findViewById(R.id.Usuario);
        Rpass = (EditText) findViewById(R.id.pass);
        Rgen = (Spinner) findViewById(R.id.genero);
        Rstate = (Spinner) findViewById(R.id.estado);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.pregistro, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.

        int id = item.getItemId();

        switch (id){
            case R.id.cancelar:
                Toast.makeText(this, "Regresando a la pantalla de Inicio ='(", Toast.LENGTH_SHORT).show();
                finish();
                Log.v(TAG, "Cancelada el Registro");
                return true;
            default:
                return onOptionsItemSelected(item);
        }
    }

    public void Registrar(View view){
        Toast.makeText(this, "Gracias por Registrarte", Toast.LENGTH_SHORT).show();
        finish();
        Log.v(TAG, "Se ha registrado satisfactoriamente");


        //Aqui obtendremos los datos para insertarlo en la BD

        String Ename = Rname.getText().toString();
        String Euser = Rusername.getText().toString();
        String Epass = Rpass.getText().toString();
        String Egen = Rgen.getOnItemSelectedListener().toString();
        String Esta = Rstate.getOnItemSelectedListener().toString();

        long id = SavacDataBaseAdap.InsertData(Ename, Euser, Epass, Egen, Esta);

        if (id < 0){
            Toast.makeText(this, "No se pudo registrar", Toast.LENGTH_LONG).show();
            Log.v(TAG, "No se pudo Resigtrar el Usuario");
        } else {
            Toast.makeText(this, "Bienvenido " +Euser, Toast.LENGTH_LONG).show();
            Log.v(TAG, "Se pudo registrar el Usuario");
        }
    }
}

XML 注册：

<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"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="com.example.yiquishum.savac4k.Pregistro">

<EditText
    android:layout_width="200dp"
    android:layout_height="wrap_content"
    android:id="@+id/nombre"
    android:hint="Nombre"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:gravity="center"/>

<EditText
    android:layout_width="200dp"
    android:layout_height="wrap_content"
    android:id="@+id/Usuario"
    android:hint="Nombre de Usuario"
    android:layout_below="@+id/nombre"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="41dp"
    android:gravity="center"/>

<EditText
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:inputType="textPassword"
    android:ems="10"
    android:id="@+id/pass"
    android:hint="@string/pass"
    android:gravity="center"
    android:layout_below="@+id/Usuario"
    android:layout_alignLeft="@+id/Usuario"
    android:layout_alignStart="@+id/Usuario"
    android:layout_marginTop="38dp" />

<Spinner
    android:layout_width="200dp"
    android:layout_height="wrap_content"
    android:id="@+id/genero"
    android:layout_centerVertical="true"
    android:layout_alignStart="@+id/pass" />

<Spinner
    android:layout_width="200dp"
    android:layout_height="wrap_content"
    android:id="@+id/estado"
    android:layout_below="@+id/genero"
    android:layout_alignStart="@+id/genero" />

<Button
    android:layout_width="200dp"
    android:layout_height="wrap_content"
    android:text="Registrar"
    android:id="@+id/button1"
    android:layout_below="@+id/estado"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="39dp"
    android:onClick="Registrar"/>

堆栈跟踪

08-19 15:08:09.597: E/AndroidRuntime(19838): FATAL EXCEPTION: main
08-19 15:08:09.597: E/AndroidRuntime(19838): Process: com.example.yiquishum.savac4k, PID: 19838
08-19 15:08:09.597: E/AndroidRuntime(19838): java.lang.IllegalStateException: Could not execute method of the activity
08-19 15:08:09.597: E/AndroidRuntime(19838):    at android.view.View$1.onClick(View.java:3823)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at android.view.View.performClick(View.java:4438)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at android.view.View$PerformClick.run(View.java:18422)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at android.os.Handler.handleCallback(Handler.java:733)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at android.os.Handler.dispatchMessage(Handler.java:95)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at android.os.Looper.loop(Looper.java:136)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at android.app.ActivityThread.main(ActivityThread.java:5017)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at java.lang.reflect.Method.invokeNative(Native Method)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at java.lang.reflect.Method.invoke(Method.java:515)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at dalvik.system.NativeStart.main(Native Method)
08-19 15:08:09.597: E/AndroidRuntime(19838): Caused by: java.lang.reflect.InvocationTargetException
08-19 15:08:09.597: E/AndroidRuntime(19838):    at java.lang.reflect.Method.invokeNative(Native Method)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at java.lang.reflect.Method.invoke(Method.java:515)
08-19 15:08:09.597: E/AndroidRuntime(19838):    at android.view.View$1.onClick(View.java:3818)
08-19 15:08:09.597: E/AndroidRuntime(19838):    ... 11 more
08-19 15:08:09.597: E/AndroidRuntime(19838): Caused by: java.lang.NullPointerException
08-19 15:08:09.597: E/AndroidRuntime(19838):    at com.example.yiquishum.savac4k.Pregistro.Registrar(Pregistro.java:92)
08-19 15:08:09.597: E/AndroidRuntime(19838):    ... 14 more

如果您需要他们告诉我的更多信息，谢谢大家 :)

Answer 1

正如其他人所指出的，当您尝试检索 Rgen.getOnItemSelectedListener() 时，您遇到了 NPE。如果你没有设置 OnItemSelectedListener，这个方法将返回 null，这会在尝试调用 toString() 时导致 NPE。

确保在尝试检索和使用它之前设置 OnItemSelectedListener。你在这里有一些例子：

http://developer.android.com/guide/topics/ui/controls/spinner.html

Answer 2

您将在String Egen = Rgen.getOnItemSelectedListener().toString(); 上获得 NPE 您需要在访问它之前获取微调器值： 您可以使用如下代码获取微调器值：

Rgen.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
        Object item = parent.getItemAtPosition(pos);
    }
    public void onNothingSelected(AdapterView<?> parent) {
    }
});