嘿，我试图在按钮OnClick上将数据插入sqLite，但得到以下异常：
logcat的：
03-24 17:54:14.773: D/AndroidRuntime(1579): --------- beginning of crash
03-24 17:54:14.774: E/AndroidRuntime(1579): FATAL EXCEPTION: main
03-24 17:54:14.774: E/AndroidRuntime(1579): Process: com.snappy.stevekamau.cosmeticsapp, PID: 1579
03-24 17:54:14.774: E/AndroidRuntime(1579): java.lang.IllegalStateException: Could not execute method of the activity
03-24 17:54:14.774: E/AndroidRuntime(1579): at android.view.View$1.onClick(View.java:4007)
03-24 17:54:14.774: E/AndroidRuntime(1579): at android.view.View.performClick(View.java:4756)
03-24 17:54:14.774: E/AndroidRuntime(1579): at android.view.View$PerformClick.run(View.java:19749)
03-24 17:54:14.774: E/AndroidRuntime(1579): at android.os.Handler.handleCallback(Handler.java:739)
03-24 17:54:14.774: E/AndroidRuntime(1579): at android.os.Handler.dispatchMessage(Handler.java:95)
03-24 17:54:14.774: E/AndroidRuntime(1579): at android.os.Looper.loop(Looper.java:135)
03-24 17:54:14.774: E/AndroidRuntime(1579): at android.app.ActivityThread.main(ActivityThread.java:5221)
03-24 17:54:14.774: E/AndroidRuntime(1579): at java.lang.reflect.Method.invoke(Native Method)
03-24 17:54:14.774: E/AndroidRuntime(1579): at java.lang.reflect.Method.invoke(Method.java:372)
03-24 17:54:14.774: E/AndroidRuntime(1579): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
03-24 17:54:14.774: E/AndroidRuntime(1579): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
03-24 17:54:14.774: E/AndroidRuntime(1579): Caused by: java.lang.reflect.InvocationTargetException
03-24 17:54:14.774: E/AndroidRuntime(1579): at java.lang.reflect.Method.invoke(Native Method)
03-24 17:54:14.774: E/AndroidRuntime(1579): at java.lang.reflect.Method.invoke(Method.java:372)
03-24 17:54:14.774: E/AndroidRuntime(1579): at android.view.View$1.onClick(View.java:4002)
03-24 17:54:14.774: E/AndroidRuntime(1579): ... 10 more
03-24 17:54:14.774: E/AndroidRuntime(1579): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.widget.TextView.getText()' on a null object reference
03-24 17:54:14.774: E/AndroidRuntime(1579): at com.snappy.stevekamau.cosmeticsapp.Details.run(Details.java:83)
03-24 17:54:14.774: E/AndroidRuntime(1579): ... 13 more
DBHelper：
public class DBHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME = "MyDBName.db";
public static final String CONTACTS_TABLE_NAME = "contacts";
public static final String CONTACTS_COLUMN_ID = "id";
public static final String CONTACTS_COLUMN_NAME = "name";
public static final String CONTACTS_COLUMN_EMAIL = "email";
public static final String CONTACTS_COLUMN_PHONE = "phone";
private HashMap hp;
public DBHelper(Context context)
{
super(context, DATABASE_NAME , null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(
"create table contacts " +
"(id integer primary key, title text,phone text,email text)"
);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS contacts");
onCreate(db);
}
public boolean insertContact (String name, String phone, String email)
{
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put("title", name);
contentValues.put("amount", phone);
contentValues.put("description", email);
db.insert("contacts", null, contentValues);
return true;
}
public Cursor getData(int id){
SQLiteDatabase db = this.getReadableDatabase();
Cursor res = db.rawQuery( "select * from contacts where id="+id+"", null );
return res;
}
public int numberOfRows(){
SQLiteDatabase db = this.getReadableDatabase();
int numRows = (int) DatabaseUtils.queryNumEntries(db, CONTACTS_TABLE_NAME);
return numRows;
}
public boolean updateContact (Integer id, String name, String phone, String email)
{
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put("title", name);
contentValues.put("amount", phone);
contentValues.put("description", email);
db.update("contacts", contentValues, "id = ? ", new String[] { Integer.toString(id) } );
return true;
}
public Integer deleteContact (Integer id)
{
SQLiteDatabase db = this.getWritableDatabase();
return db.delete("contacts",
"id = ? ",
new String[] { Integer.toString(id) });
}
public ArrayList getAllCotacts()
{
ArrayList array_list = new ArrayList();
//hp = new HashMap();
SQLiteDatabase db = this.getReadableDatabase();
Cursor res = db.rawQuery( "select * from contacts", null );
res.moveToFirst();
while(res.isAfterLast() == false){
array_list.add(res.getString(res.getColumnIndex(CONTACTS_COLUMN_NAME)));
res.moveToNext();
}
return array_list;
}
}
MyBasket.java：
public class MyBasket extends ActionBarActivity {
private ListView obj;
DBHelper mydb;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my_basket);
Toolbar toolbar = (Toolbar) findViewById(R.id.app_bar);
setSupportActionBar(toolbar);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mydb = new DBHelper(this);
ArrayList array_list = mydb.getAllCotacts();
ArrayAdapter arrayAdapter =
new ArrayAdapter(this,android.R.layout.simple_list_item_1, array_list);
//adding it to the list view.
obj = (ListView)findViewById(R.id.listView1);
obj.setAdapter(arrayAdapter);
Button basketButton = (Button) findViewById(R.id.checkout);
basketButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(MyBasket.this);
alertDialog.setCancelable(false);
alertDialog.setMessage("Done with shopping?");
alertDialog.setPositiveButton("Proceed to checkout", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(MyBasket.this, CheckOut.class);
startActivity(intent);
}
});
alertDialog.setNegativeButton("Go back to shop for more", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent i = new Intent(MyBasket.this, MainActivity.class);
startActivity(i);
}
});
alertDialog.show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_my_basket, 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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
if (id == android.R.id.home) {
NavUtils.navigateUpFromSameTask(this);
}
return super.onOptionsItemSelected(item);
}
public boolean onKeyDown(int keycode, KeyEvent event) {
if (keycode == KeyEvent.KEYCODE_BACK) {
moveTaskToBack(true);
}
return super.onKeyDown(keycode, event);
}
Details.java：
public class Details extends ActionBarActivity {
private static String Title = "title";
private static String Rate = "rating";
private static String Genre = "genre";
private DBHelper mydb;
int id_To_Update = 0;
TextView title;
TextView amount ;
TextView description;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_details);
Toolbar toolbar = (Toolbar) findViewById(R.id.app_bar);
setSupportActionBar(toolbar);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mydb = new DBHelper(this);
Intent i = getIntent();
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
String bitmap = i.getStringExtra("images");
final String name = i.getStringExtra(Title);
String rate = i.getStringExtra(Rate);
String genres = i.getStringExtra(Genre);
final Button thirdBtn = (Button) findViewById(R.id.third);
thirdBtn.setVisibility(View.VISIBLE);
TextView title = (TextView) findViewById(R.id.title_label);
TextView amount = (TextView) findViewById(R.id.amount_label);
TextView description = (TextView) findViewById(R.id.description_label);
NetworkImageView thumbNail = (NetworkImageView) findViewById(R.id.img2);
thumbNail.setImageUrl(bitmap, imageLoader);
title.setText(name);
amount.setText(rate);
description.setText(genres);
}
public void run(View view) {
Bundle extras = getIntent().getExtras();
if (extras != null) {
int Value = extras.getInt("id");
if (Value > 0) {
if (mydb.updateContact(id_To_Update, title.getText().toString(),amount.getText().toString(), description.getText().toString())) {
Toast.makeText(getApplicationContext(), "Updated", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(getApplicationContext(), MyBasket.class);
startActivity(intent);
} else {
Toast.makeText(getApplicationContext(), "not Updated", Toast.LENGTH_SHORT).show();
}
} else {
if (mydb.insertContact(title.getText().toString(),amount.getText().toString(), description.getText().toString())) {
Toast.makeText(getApplicationContext(), "done", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), "not done", Toast.LENGTH_SHORT).show();
}
Intent intent = new Intent(getApplicationContext(), MyBasket.class);
startActivity(intent);
}
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_next, 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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
if (id == android.R.id.home) {
NavUtils.navigateUpFromSameTask(this);
}
return super.onOptionsItemSelected(item);
}
}
答案 0 :(得分：0)
引起：java.lang.NullPointerException：尝试调用虚方法＆＃39; java.lang.CharSequence android.widget.TextView.getText（）＆＃39;在null对象引用上。通常，这意味着您的员工尚未初始化。检查Details.java中的第83行。