我会直截了当地说。我有一个班级，我有6个按钮。每个按钮将一些参数保存到SQLiteDatabase，然后启动一个Activity。
新的Activity采用参数并查询数据库以相应地提取数据。当活动启动时，我清除参数，以便在我按下另一个或相同的按钮时再次保存它们。
如果1个表（链接到该按钮）为空，则返回我想要的消息。问题是如果1为空，那么所有表都会返回消息，即使它们有数据!!
我的第一堂课
public class HRecords extends Activity {
SQLiteDatabase myDB=null;
Button tes,con,al,me,pr,va;
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.records);
tes=(Button) findViewById(R.id.testbut);
con=(Button) findViewById(R.id.condbut);
al=(Button) findViewById(R.id.albut);
me=(Button) findViewById(R.id.medbut);
pr=(Button) findViewById(R.id.procbut);
va=(Button) findViewById(R.id.vacbut);
Database openHelper = new Database(this);//create new Database to take advantage of the SQLiteOpenHelper class
myDB = openHelper.getWritableDatabase(); // or getWritableDatabase();
myDB=SQLiteDatabase.openDatabase("data/data/com.example.login2/databases/aeglea", null, SQLiteDatabase.OPEN_READWRITE);//set myDB to aeglea
doclicks();
}
private void doclicks(){
tes.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
ContentValues values = new ContentValues();
values.put("ton", "Tests");
values.put("tazle","user_test");
myDB.insert("history_go",null, values);
//create new intent
Intent record = new Intent(getApplicationContext(), Record.class);
// Close all views before launching logged
record.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(record);
// Close Login Screen
onPause();
}});
con.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
ContentValues values = new ContentValues();
values.put("ton", "Medical Conditions");
values.put("tazle","user_cond");
myDB.insert("history_go",null, values);
//create new intent
Intent record = new Intent(getApplicationContext(), Record.class);
// Close all views before launching logged
record.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(record);
// Close Login Screen
onPause();
}});
al.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
ContentValues values = new ContentValues();
values.put("ton", "Allergies");
values.put("tazle","user_all");
myDB.insert("history_go",null, values);
//create new intent
Intent record = new Intent(getApplicationContext(), Record.class);
// Close all views before launching logged
record.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(record);
// Close Login Screen
onPause();
}});
me.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
ContentValues values = new ContentValues();
values.put("ton", "Medication");
values.put("tazle","user_med");
myDB.insert("history_go",null, values);
//create new intent
Intent record = new Intent(getApplicationContext(), Record.class);
// Close all views before launching logged
record.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(record);
// Close Login Screen
onPause();
}});
pr.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
ContentValues values = new ContentValues();
values.put("ton", "Medical Procedures");
values.put("tazle","user_proc");
myDB.insert("history_go",null, values);
//create new intent
Intent record = new Intent(getApplicationContext(), Record.class);
// Close all views before launching logged
record.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(record);
// Close Login Screen
onPause();
}});
va.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
ContentValues values = new ContentValues();
values.put("ton", "Vaccinations");
values.put("tazle","user_vacc");
myDB.insert("history_go",null, values);
//create new intent
Intent record = new Intent(getApplicationContext(), Record.class);
// Close all views before launching logged
record.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(record);
// Close Login Screen
onPause();
}});
}
}
第二个类，你可以看到它从SQLite数据库中提取数据（你也可以看到消息显示空结果＆＃34;此处没有添加任何内容。转到网站添加更多内容。＆＃34;）< / p>
public class Record extends Activity{
SQLiteDatabase myDB=null;
TextView title=null;
Cursor cur,cur2=null;
ListView list=null;
private ArrayAdapter<String> listAdapter ;
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.record);
title = (TextView) findViewById(R.id.recordTitle);
list = (ListView) findViewById(R.id.listView1);
Database openHelper = new Database(this);
myDB = openHelper.getReadableDatabase();
myDB=SQLiteDatabase.openDatabase("data/data/com.example.login2/databases/aeglea", null, SQLiteDatabase.OPEN_READONLY);
Database db = new Database(getApplicationContext());
cur = fetchOption("SELECT * FROM history_go");
title.setText(cur.getString(cur.getColumnIndex("ton")));
ArrayList<String> itemlist = new ArrayList<String>();
String[] names=null;
//do query
cur2=fetchOption("SELECT * FROM "+cur.getString(cur.getColumnIndex("tazle")));
//check for results
if (cur2.getCount()==0) {
names = new String[] { "Nothing Added here. Go to the site to add more."};
}else{
names = new String[] {cur2.getString(cur2.getColumnIndex("name"))};
}
//add the array as list to the ArrayList
itemlist.addAll( Arrays.asList(names) );
listAdapter = new ArrayAdapter<String>(this, R.layout.item, itemlist);
//if results add the rest
if(cur2.getCount()!=0){
for(int i=0;i<(cur2.getCount()-1);i++){
cur2.moveToNext();
listAdapter.add(cur2.getString(cur2.getColumnIndex("name")));
}
}
// Set the ArrayAdapter as the ListView's adapter.
list.setAdapter(listAdapter);
//remove the navigation history
db.resetHistoryNavigation();
cur.close();
cur2.close();
}
public Cursor fetchOption(String query) throws SQLException {
Cursor mCursor = myDB.rawQuery(query, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
}
修改
另外，我忘了提到如果我将验证条件设置为cur2 == null，应用程序会因为光标超出范围而崩溃（for循环触发）
答案 0 :(得分：0)
我发现了什么问题。空集触发了catch异常，之后没有收到任何其他内容。所以每个表都是null。
我必须实现多个try / catch
private void doclicks(){
hr.setOnClickListener(new View.OnClickListener() {
private Database db = new Database(getApplicationContext());
JSONArray allergy,condition,medication,procedure,test,vaccine;
public void onClick(View v) {
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("uid", cursor.getString(cursor.getColumnIndex("uid"))));
JSONObject response = null;
try {
CustomHttpTask asdf = new CustomHttpTask();
response = asdf.execute("http://192.168.1.4/aeglea/android/history.php", postParameters).get();
if(response.getString("success").equals("1")){
//get JSON Arrays
try{test = response.getJSONArray("test");}catch(Exception e){}
try{allergy = response.getJSONArray("allergy");}catch(Exception e){}
try{condition = response.getJSONArray("condition");}catch(Exception e){}
try{medication = response.getJSONArray("medication");}catch(Exception e){}
try{procedure = response.getJSONArray("procedure");}catch(Exception e){}
try{vaccine = response.getJSONArray("vaccine");}catch(Exception e){}
}
}catch (Exception e) {
Log.e("HHHERPT","YO MAMAA "+e);
}
//temp JSONOnject
JSONObject buffer=null;
//reset older values
db.resetHistory();
//Store values
try{
for(int i=0;i<allergy.length();i++){
buffer=allergy.getJSONObject(i);
db.addRecords("allergy",
Integer.parseInt(buffer.getString("id")),
Integer.parseInt(buffer.getString("uid")),
buffer.getString("name"),
1,
"",
(float) 0.1,
1,
1);
}
}catch(Exception e){
}
try{
for(int i=0;i<condition.length();i++){
buffer=condition.getJSONObject(i);
db.addRecords("condition",
Integer.parseInt(buffer.getString("id")),
Integer.parseInt(buffer.getString("uid")),
buffer.getString("name"),
Integer.parseInt(buffer.getString("year")) ,
"",(float) 0.1,
Integer.parseInt(buffer.getString("current")),
1);
}
}catch(Exception e){
}
try{
for(int i=0;i<medication.length();i++){
buffer=medication.getJSONObject(i);
db.addRecords("medication",
Integer.parseInt(buffer.getString("id")),
Integer.parseInt(buffer.getString("uid")),
buffer.getString("name"),
1,
"",
(float) 0.1,
Integer.parseInt(buffer.getString("current")),
1);
}
}catch(Exception e){
}
try{
for(int i=0;i<procedure.length();i++){
buffer=procedure.getJSONObject(i);
db.addRecords("procedure",
Integer.parseInt(buffer.getString("id")),
Integer.parseInt(buffer.getString("uid")),
buffer.getString("name"),
Integer.parseInt(buffer.getString("year")),
buffer.getString("comments"),
(float) 0.1,
0,
1);
}
}catch(Exception e){
}
try{
for(int i=0;i<vaccine.length();i++){
buffer=vaccine.getJSONObject(i);
db.addRecords("vaccine",
Integer.parseInt(buffer.getString("id")),
Integer.parseInt(buffer.getString("uid")),
buffer.getString("name"),
Integer.parseInt(buffer.getString("year")),
"",
(float) 0.1,
0,
1);
}
}catch(Exception e){
}
try{
for(int i=0;i<test.length();i++){
buffer=test.getJSONObject(i);
db.addRecords("test",
Integer.parseInt(buffer.getString("id")),
Integer.parseInt(buffer.getString("uid")),
buffer.getString("name"),
Integer.parseInt(buffer.getString("year")),
buffer.getString("comments"),
(float) Float.parseFloat(buffer.getString("value")),
1,
1);
}
}catch(Exception e){
}
//create new intent
Intent records = new Intent(getApplicationContext(), HRecords.class);
// Close all views before launching logged
records.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(records);
// Close Login Screen
onPause();
}
});
}