所以这是我在Stackoverflow上的第一个问题。如果我能够正确地提出我的问题，那就让我们看看：
我有一个SQLite DB（lights_db）和两个Spinners（spinnerLightType和spinnerLightSelector）。取决于spinnerLightType中的选择（＆＃34; HMI＆＃34;，＆＃34; Tungsten＆＃34;，＆＃34; Fluorescent＆＃34;或＆＃34; LED＆＃34;），我喜欢通过使用查询中的选择将不同的light_db项加载到spinnerLightSelector中。查询很好，Cursor有数据，问题是它只是没有在微调器中显示它，我无法弄清楚原因。
以下是MainActivity代码的一部分：
public class MainActivity extends ActionBarActivity {
double Transmission = 1.0;
double Z = 1.0;
Light_SQL light_db = new Light_SQL(this);
Spinner spinnerLightType, spinnerLightSelector;
public Context mContext;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// add lights to light_db
createLightDB();
mContext = this;
spinnerLightType = (Spinner) findViewById(R.id.spinnerLightType);
spinnerLightType.setSelection(1);
spinnerLightType.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent, View view, int pos, long id){
System.out.println("Technology set to : " + parent.getItemAtPosition(pos).toString());
Cursor light_cc = light_db.getWritableDatabase().query("lights", // a. table
new String[]{"id AS _id", "technology", "name"}, // b. column names
"technology=?", // c. selections
new String[]{parent.getItemAtPosition(pos).toString()}, // d. selections args
null, // e. group by
null, // f. having
null, // g. order by
null); // h. limit
if (light_cc.moveToFirst()) {
do {
System.out.println("Item : " + light_cc.getString(0) + "Technology : " + light_cc.getString(1) + " name : " + light_cc.getString(2));
} while (light_cc.moveToNext());
}
String[] from = new String[] {"name"};
int[] to = new int[] {android.R.id.text1};
SimpleCursorAdapter light_sca = new SimpleCursorAdapter(mContext, android.R.layout.simple_spinner_item, light_cc, from, to);
light_sca.setDropDownViewResource(android.R.layout.simple_spinner_item);
spinnerLightSelector.setAdapter(light_sca);
light_cc.close();
}
public void onNothingSelected(AdapterView<?> parent) {}
});
spinnerLightSelector = (Spinner) findViewById(R.id.spinnerLightSelector);
spinnerLightSelector.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent, View view, int position, long id){
Z = light_db.getLight((int) id).getZ();
System.out.println("Z set to : " + Z);
}
public void onNothingSelected(AdapterView<?> parent) {}
});
@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_main, 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;
}
return super.onOptionsItemSelected(item);
}
}
public void createLightDB() {
// HMI
// ARRI PocketPar
light_db.addLight(new Light("HMI","ARRI PocketPar 150", 150, 3.67));
light_db.addLight(new Light("HMI","ARRI PocketPar 200", 200, 2.49));
light_db.addLight(new Light("HMI","ARRI PocketPar 400", 400, 1.94));
// K5600 Joker-Series
light_db.addLight(new Light("HMI","K5600 Joker 200", 200, 2.44));
light_db.addLight(new Light("HMI","K5600 Joker 400", 400, 2.44));
light_db.addLight(new Light("HMI","K5600 Joker 800", 800, 1.45));
light_db.addLight(new Light("HMI","K5600 Joker 1600", 1600, 0.67));
// K5600 Alpha-Series
light_db.addLight(new Light("HMI","K5600 Alpha 4k", 200, 0.45));
light_db.addLight(new Light("HMI","K5600 Alpha 18k", 400, 0.28));
// Arri D-Series
light_db.addLight(new Light("HMI","ARRI D5", 575, 1.78));
light_db.addLight(new Light("HMI","ARRI D12", 1200, 1.14));
light_db.addLight(new Light("HMI","ARRI D25", 2500, 0.87));
light_db.addLight(new Light("HMI","ARRI D40", 4000, 0.69));
// ArriSun series
light_db.addLight(new Light("HMI","ARRISUN 25", 2500, 0.87));
light_db.addLight(new Light("HMI","ARRISUN 40", 4000, 0.69));
// Arri Compact
light_db.addLight(new Light("HMI","ARRI Compact 6000", 6000, 0.54));
// Arri M-Series
light_db.addLight(new Light("HMI","ARRI M8", 800, 1.49));
light_db.addLight(new Light("HMI","ARRI M18", 1800, 0.96));
light_db.addLight(new Light("HMI","ARRI M25", 2500, 0.96));
light_db.addLight(new Light("HMI","ARRI M40", 4000, 0.60));
light_db.addLight(new Light("HMI","ARRI M90", 9000, 0.34));
// Arri Daylight-Series
light_db.addLight(new Light("HMI","ARRI Daylight 12", 12000, 0.42));
light_db.addLight(new Light("HMI","ARRI Daylight 18", 18000, 0.36));
light_db.addLight(new Light("HMI","ARRIMAX 18", 18000, 0.27));
// Tungstene
// Fresnels
light_db.addLight(new Light("Tungsten","150 W Fresnel", 150, 6.76));
light_db.addLight(new Light("Tungsten","300 W Fresnel", 300, 4.78));
light_db.addLight(new Light("Tungsten","650 W Fresnel", 650, 2.68));
light_db.addLight(new Light("Tungsten","1 kW Fresnel", 1000, 2.04));
light_db.addLight(new Light("Tungsten","2 kW Fresnel", 2000, 1.60));
light_db.addLight(new Light("Tungsten","5 kW Fresnel", 50000, 0.83));
light_db.addLight(new Light("Tungsten","10 kW Fresnel", 10000, 0.62));
light_db.addLight(new Light("Tungsten","12 W Fresnel", 12000, 0.56));
light_db.addLight(new Light("Tungsten","20 kW Fresnel", 20000, 0.46));
light_db.addLight(new Light("Tungsten","24 W Fresnel", 240000, 0.42));
// Open Face
light_db.addLight(new Light("Tungsten","800 W Open Face", 2000, 2.36));
light_db.addLight(new Light("Tungsten","2 kW Open Face", 2000, 1.99));
// Fluorescent
// KinoFlo
light_db.addLight(new Light("Fluorescent","KinoFlo 4ft 4Bank", 300, 5.21));
light_db.addLight(new Light("Fluorescent","KinoFlo 4ft 2Bank", 150, 7.17));
light_db.addLight(new Light("Fluorescent","KinoFlo 2ft 4Bank", 160, 0.78));
light_db.addLight(new Light("Fluorescent","KinoFlo 2ft 2Bank", 80, 12.42));
light_db.addLight(new Light("Fluorescent","KinoFlo 4ft 1Bank", 75, 9.56));
light_db.addLight(new Light("Fluorescent","KinoFlo 2ft 1Bank", 40, 17.56));
// LED
// LitePanel
light_db.addLight(new Light("LED","LitePanel 30x30", 40, 4.57));
}
}
这里是logcat（证明光标肯定有数据，我选择＆＃34; LED＆＃34;然后＆＃34; Fluorescent＆＃34;在spinnerLightType中）：
01-16 13:17:42.144 31987-31987/com.example.georges.benilux I/System.out﹕ Item : 43 Technology : LED name : LitePanel 30x30
01-16 13:17:47.409 31987-31987/com.example.georges.benilux I/System.out﹕ Technology set to : Fluorescent
01-16 13:17:47.413 31987-31987/com.example.georges.benilux I/System.out﹕ Item : 37 Technology : Fluorescent name : KinoFlo 4ft 4Bank
01-16 13:17:47.413 31987-31987/com.example.georges.benilux I/System.out﹕ Item : 38 Technology : Fluorescent name : KinoFlo 4ft 2Bank
01-16 13:17:47.413 31987-31987/com.example.georges.benilux I/System.out﹕ Item : 39 Technology : Fluorescent name : KinoFlo 2ft 4Bank
01-16 13:17:47.413 31987-31987/com.example.georges.benilux I/System.out﹕ Item : 40 Technology : Fluorescent name : KinoFlo 2ft 2Bank
01-16 13:17:47.413 31987-31987/com.example.georges.benilux I/System.out﹕ Item : 41 Technology : Fluorescent name : KinoFlo 4ft 1Bank
01-16 13:17:47.413 31987-31987/com.example.georges.benilux I/System.out﹕ Item : 42 Technology : Fluorescent name : KinoFlo 2ft 1Bank
那么，为什么光标中的数据不会出现在LightTypeSelector中？其他问题：为什么Android Studio会告诉我＆＃34; SimpleCursorAdapter＆＃34;折旧...
答案 0 :(得分：0)
Android Studio可能会告诉您，不推荐使用SimpleCursorAdapter的构造函数：
public SimpleCursorAdapter (Context context, int layout, Cursor c, String[] from, int[] to)
在API级别1中添加 在API级别11中不推荐使用此构造函数。
请参阅Android文档：http://developer.android.com/reference/android/widget/SimpleCursorAdapter.html