[英]Saving Spinner selection into SQLite database
我查看了所有與將微調器保存到數據庫有關的問題,但似乎沒有任何效果。
我已經開始着手添加ItemSelectedListener
但是它會拋出一個錯誤,
這是我的代碼
OnItemSelectedListener
在這里是我在其余表格中插入的位置
public class OnClickListenerCreateMenuItem implements View.OnClickListener {
@Override
public void onClick(View view) {
final Context context = view.getContext();
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final View formElementsView = inflater.inflate(R.layout.menuitem_input_form, null, false);
final EditText editTextItemName = (EditText) formElementsView.findViewById(R.id.editTextItemName);
final EditText editTextItemDesc = (EditText) formElementsView.findViewById(R.id.editTextItemDesc);
final EditText editTextItemPrice = (EditText) formElementsView.findViewById(R.id.editTextItemPrice);
final EditText editTextItemCost = (EditText) formElementsView.findViewById(R.id.editTextItemCost);
final Spinner itemCategory = (Spinner) formElementsView.findViewById(R.id.spinnerCategory);
itemCategory.setAdapter(
((SettingsMenuItem) context).loadSpinnerData()
);
itemCategory.setOnItemSelectedListener(
((SettingsMenuItem) context).loadSpinnerData()
);
new AlertDialog.Builder(context)
.setView(formElementsView)
.setTitle("Create Item")
.setPositiveButton("Add",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
String itemName = editTextItemName.getText().toString();
String itemDescription = editTextItemDesc.getText().toString();
String itemPrice = editTextItemPrice.getText().toString();
String itemCost = editTextItemCost.getText().toString();
String valueOfSelectedCat= itemCategory.getSelectedItem().toString();
ObjectMenuItem objectMenuItem = new ObjectMenuItem();
objectMenuItem.name = itemName;
objectMenuItem.description = itemDescription;
objectMenuItem.price = Float.parseFloat(itemPrice);
objectMenuItem.cost = Float.parseFloat(itemCost);
objectMenuItem.cat = valueOfSelectedCat;
boolean createSuccessful = new TableControllerMenuItem(context).create(objectMenuItem);
if(createSuccessful){
Toast.makeText(context, "Item was saved.", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(context, "Unable to save item.", Toast.LENGTH_SHORT).show();
}
((SettingsMenuItem) context).readRecords();
((SettingsMenuItem) context).countRecords();
dialog.cancel();
}
}).show();
}
我的實際微調器在這里設置並填充
public class SettingsMenuItem extends AppCompatActivity {
Spinner spinner;
Context context;
String id;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings_menu_item);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
countRecords();
readRecords();
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
Button buttonCreateLocation = (Button) findViewById(R.id.btnAdd);
buttonCreateLocation.setOnClickListener(new OnClickListenerCreateMenuItem());
}
public void countRecords() {
int recordCount = new TableControllerMenuItem(this).count();
TextView textViewRecordCount = (TextView) findViewById(R.id.textViewRecordCount);
textViewRecordCount.setText(recordCount + " records found.");
}
public void readRecords() {
LinearLayout linearLayoutRecords = (LinearLayout) findViewById(R.id.linearLayoutRecords);
linearLayoutRecords.removeAllViews();
List<ObjectMenuItem> menuitem = new TableControllerMenuItem(this).read();
if (menuitem.size() > 0) {
for (ObjectMenuItem obj : menuitem) {
int id = obj.id;
String menuitemName = obj.name;
String menuitemDescription = obj.description;
Float menuitemPrice = obj.price;
Float menuitemCost = obj.cost;
String itemCategory = obj.cat;
String textViewContents = menuitemName;
TextView textViewMenuItem = new TextView(this);
textViewMenuItem.setPadding(0, 10, 0, 10);
textViewMenuItem.setText(textViewContents);
textViewMenuItem.setTag(Integer.toString(id));
textViewMenuItem.setTextSize(20.0f);
textViewMenuItem.setOnLongClickListener(new OnLongClickListenerMenuItem());
linearLayoutRecords.addView(textViewMenuItem);
}
} else {
TextView locationItem = new TextView(this);
locationItem.setPadding(8, 8, 8, 8);
locationItem.setText("No records yet.");
linearLayoutRecords.addView(locationItem);
}
}
public ArrayAdapter loadSpinnerData() {
Log.d("CON", "setting spinner data");
Spinner s = (Spinner) findViewById(R.id.spinnerCategory);
DatabaseHandler h = new DatabaseHandler(getApplicationContext());
List<String> names = h.getAllNames();
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, names);
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
return dataAdapter;
}
}
這是我的崩潰日志
---------崩潰開始02-14 08:29:07.627 14332-14332 / com.jenovaprojects.restaurant E / AndroidRuntime:致命例外:主要過程:com.jenovaprojects.restaurant,PID:14332 java。 lang.ClassCastException:android.widget.ArrayAdapter無法在com.jenovaprojects.restaurant.OnClickListenerCreate.OnClickListenerCreateMenuItem.onClick(OnClickListenerCreateMenuItem.java:41)上轉換為android.widget.AdapterView $ OnItemSelectedListener,在android.view.View.performClick(View。 java:5204)位於android.view.View $ PerformClick.run(View.java:21156)位於android.os.Handler.handleCallback(Handler.java:739)位於android.os.Handler.dispatchMessage(Handler.java:95) )在android.os.Looper.loop(Looper.java:148)在android.app.ActivityThread.main(ActivityThread.java:5466)在com.android的java.lang.reflect.Method.invoke(本機方法)。 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)上的internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:726)
使用Android指南中的這段代碼,您應該能夠實現OnItemSelectedListener
public class SpinnerActivity extends Activity implements OnItemSelectedListener {
...
public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
// An item was selected. You can retrieve the selected item using
parent.getItemAtPosition(pos)
}
}
我不確定為什么它不起作用,但是如果沒有更多的代碼,很難說出來。 如果這樣做沒有幫助,請發布您用來保存選擇的代碼,以便我們嘗試找出正在發生的情況。
請放置LogCat來查看這些錯誤,並在可能的情況下顯示數據庫查詢和表結構,以在其中插入所選數據。
簡單的過程是在您的案例中將一個onItemSelected偵聽器放在微調器上
itemCategory.setOnItemSelectedListener(replce your context here);
然后做微調界面的必要實現
實現OnItemSelectedListener
當您從微調器中選擇任何項目時,將調用onItemSelected方法。 它將返回您單擊的項目的位置,從中可以輕松找出單擊了哪個項目。
adapter.getItemAtPosition(pos).toString()
通過此操作,您將獲得項目的文本。
第二部分 - 將數據插入sqlite數據庫
創建一個db對象並對其進行初始化,然后調用適當的方法以插入您選擇的選擇數據。
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