将行插入SQLite数据库时，Android App不会崩溃

Question

您好我是Android开发的新手，我正在尝试创建一个应用程序，它将用户的姓名，邮政编码，年龄和性别添加到SQLite数据库，然后在下一页显示。我已经为此尝试了很多教程，但收效甚微。在EditText中输入数据后，按下提交按钮会导致android崩溃任何帮助将不胜感激。 这是我用户输入数据的主要活动

package com.example.votesmart;


import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;

public class Zip extends Activity {

    private static final int TIME_ENTRY_REQUEST_CODE = 1;

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

    }

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

    public void onSubmit(View view){
        Intent intent = new Intent(this, EditProfile.class);
        startActivityForResult(intent, TIME_ENTRY_REQUEST_CODE);

        EditText firstView = (EditText)findViewById(R.id.fname_input);
        intent.putExtra("first", firstView.getText().toString());

        EditText lastView = (EditText)findViewById(R.id.lname_input);
        intent.putExtra("last", lastView.getText().toString());

        EditText zipView = (EditText)findViewById(R.id.zipcode_input);
        intent.putExtra("zip", zipView.getText().toString());

        EditText ageView = (EditText)findViewById(R.id.age_input);
        intent.putExtra("age", ageView.getText().toString());

        EditText sexView = (EditText)findViewById(R.id.sex_input);
        intent.putExtra("sex", sexView.getText().toString());
    }


}

其布局

<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="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".Zip"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="First Name" />

     <EditText
        android:id="@+id/fname_input"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Last Name" />

     <EditText
        android:id="@+id/lname_input"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        />

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Zip Code" />

    <EditText
        android:id="@+id/zipcode_input"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Age" />

     <EditText
        android:id="@+id/age_input"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

     <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Sex" />

     <EditText
        android:id="@+id/sex_input"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

    <Button
        android:id="@+id/submit"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Submit"
        android:onClick="onSubmit" />

</LinearLayout>

显示数据的下一页

package com.example.votesmart;


import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ListView;

public class EditProfile extends Activity {
    VSAdapter vsAdapter;

    public static final int TIME_ENTRY_REQUEST_CODE = 1;
    private DatabaseHandler databaseHelper;
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.edit_profile);

        databaseHelper = new DatabaseHandler(this);

        ListView listView = (ListView)findViewById(R.id.list);
        vsAdapter = new VSAdapter(this, databaseHelper.getAllRecords());
        listView.setAdapter(vsAdapter); 
    }

    public void onBack (View view){
        finish();
    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data){
        if (requestCode == TIME_ENTRY_REQUEST_CODE){
            if (resultCode == RESULT_OK){

                String first = data.getStringExtra("first");
                String last = data.getStringExtra("last");
                String zip = data.getStringExtra("zip");
                String age = data.getStringExtra("age");
                String sex = data.getStringExtra("sex");

                databaseHelper.addVoter(first, last, zip, age, sex);
                //vsAdapter.changeCursor(databaseHelper.getAllRecords());

                //databaseHelper.addVoter(first, last, zip, age, sex);

            }
            }
        }
    }

我的适配器

package com.example.votesmart;

import android.content.Context;
import android.database.Cursor;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;
import android.widget.TextView;

public class VSAdapter extends CursorAdapter {

    public VSAdapter(Context context, Cursor cursor){
        super(context, cursor);
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        // TODO Auto-generated method stub
        TextView nameTextView = (TextView) view.findViewById(R.id.first_view);
        nameTextView.setText(cursor.getString(cursor.getColumnIndex("1")));
        TextView lastTextView = (TextView) view.findViewById(R.id.last_view);
        lastTextView.setText(cursor.getString(cursor.getColumnIndex("2")));
        TextView zipTextView = (TextView) view.findViewById(R.id.zip_view);
        zipTextView.setText(cursor.getString(cursor.getColumnIndex("3")));
        TextView ageTextView = (TextView) view.findViewById(R.id.age_view);
        ageTextView.setText(cursor.getString(cursor.getColumnIndex("4")));
        TextView sexTextView = (TextView) view.findViewById(R.id.sex_view);
        sexTextView.setText(cursor.getString(cursor.getColumnIndex("5")));
    }

    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        // TODO Auto-generated method stub
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        View view = inflater.inflate(R.layout.zip_list_item,  parent, false);


        return view;
    }

}
and finally my database class
private class DatabaseOpenHelper extends SQLiteOpenHelper{
        DatabaseOpenHelper(Context context){
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            // TODO Auto-generated method stub
            String CREATE_VOTERS_TABLE = "create table " + TABLE_NAME + "(" + KEY_ID + " integer primary key, " + KEY_FIRST + " text," + KEY_LAST + " text," + KEY_ZIP + " text," + KEY_AGE + " text," + KEY_SEX + "text" ;
            db.execSQL(
                    CREATE_VOTERS_TABLE
                    );
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            // TODO Auto-generated method stub
            db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
            onCreate(db);
        }
    }

        public void addVoter(String first, String last, String zip, String age, String sex){
            //public void addVoter{Voter voter){
            ContentValues values = new ContentValues();
            values.put(KEY_FIRST, first);
            values.put(KEY_LAST, last);
            values.put(KEY_ZIP, zip);
            values.put(KEY_AGE, age);
            values.put(KEY_SEX, sex);

            db.insert(TABLE_NAME, null, values);

                //return db.update(TABLE_NAME, values, KEY_ID + " = ?", new String[] {String.valueOf(voter.getId()) });
            }
        public Cursor getAllRecords(){
            return db.rawQuery(
                    "select * from " + TABLE_NAME,
                    null
                    );
        }
}

再次感谢任何帮助，谢谢！

Answer 1

这有一些问题，

public void onSubmit(View view){
        Intent intent = new Intent(this, EditProfile.class);


        EditText firstView = (EditText)findViewById(R.id.fname_input);
        intent.putExtra("first", firstView.getText().toString());

        EditText lastView = (EditText)findViewById(R.id.lname_input);
        intent.putExtra("last", lastView.getText().toString());

        EditText zipView = (EditText)findViewById(R.id.zipcode_input);
        intent.putExtra("zip", zipView.getText().toString());

        EditText ageView = (EditText)findViewById(R.id.age_input);
        intent.putExtra("age", ageView.getText().toString());

        EditText sexView = (EditText)findViewById(R.id.sex_input);
        intent.putExtra("sex", sexView.getText().toString());
        startActivityForResult(intent, TIME_ENTRY_REQUEST_CODE);
    }

您需要在发送数据之前添加数据。您使用onActivityResult的方法也是错误的，

在EditProfile类的oncreate方法中，输入以下内容

Intent data = getIntent().getExtras();

String first = data.getStringExtra("first");
String last = data.getStringExtra("last");
String zip = data.getStringExtra("zip");
String age = data.getStringExtra("age");
String sex = data.getStringExtra("sex");

databaseHelper.addVoter（first，last，zip，age，sex）;

理想情况下，这应该是一个线程但是是的。

Answer 2

在这段代码中：

public void onSubmit(View view){
        Intent intent = new Intent(this, EditProfile.class);
        startActivityForResult(intent, TIME_ENTRY_REQUEST_CODE);

您正在第3行开始您的活动，但之后您正在向意图“添加数据”......意图被“startActivity”消耗。把它放在那个街区的底部。

并且您没有在其他Activity的“onResult”中获取意图数据 - 您可以在销毁它之前设置活动的结果。收集的意图数据需要在显示活动之前 - onCreate，onStart或onResume。 OnCreate会做一次。其他用于您可能想要回收活动的情况（例如在已经开始之后添加另一个选民）。但你需要检查欺骗行为。