亲爱的stackoverflowers，
我的android应用程序中有一个数据库，我向它发送一个String并返回一个Cursor。 这是代码：
public Cursor listSearch(String phonename) {
Cursor mCursor = mDb.query(SQLITE_AllPhones, new String[] { KEY_ROWID,
KEY_OEM, KEY_PHONENAME, KEY_MODELNUMBER, KEY_AVAILABILITYDATE,
KEY_URL, KEY_URL2, KEY_URL3, KEY_RELEASEDATE, KEY_SIM,
KEY_ANDROID, KEY_COLORS, KEY_DIMENSIONS, KEY_WEIGHT,
KEY_DISPLAYTYPE, KEY_DISPLAYSIZE, KEY_RESOLUTION, KEY_PPI,
KEY_CARDSLOT, KEY_INTERNAL, KEY_CAMERA, KEY_CAMERAFLASH,
KEY_FEATURES, KEY_VIDEO, KEY_FRONTCAMERA, KEY_CHIPSET, KEY_CPU,
KEY_GPU, KEY_MEMORY, KEY_BATTERY }, null, null, null, null,
null);
if (mCursor != null) {
mCursor.moveToFirst();
}
String cursor = "Select * FROM AllPhonesTable WHERE phone_name = '"
+ phonename + "'";
Log.e("cursor", cursor);
mCursor = mDb.rawQuery(cursor, null);
return mCursor;
}
然后，我从另一个类访问该游标：
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
gotBasket = BigSpecs.this.getIntent().getExtras();
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.specs);
imageLoader = new com.androidarabia.lazylist.ImageLoader2(
getApplicationContext());
apd = new AllPhonesDatabase(this.getApplicationContext()).open();
c = apd.listSearch(gotBasket.getString("phonename"));
Log.d("cursor", "The Cursor Number" + c.getCount());
initialize();
setuptext();
}
然后我根据光标做我的工作：
private void setuptext() {
// TODO Auto-generated method stub
final String imageurl = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_URL));
imageLoader.DisplayImage(imageurl, pic1);
final String Releasedate = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_RELEASEDATE));
releasedate.setText("" + Releasedate);
final String Androidversion = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_ANDROID));
androidversion.setText("" + Androidversion);
final String Sim = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_SIM));
tvsim.setText("" + Sim);
final String Dimensions = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_DIMENSIONS));
dimensions.setText("" + Dimensions);
final String Weight = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_WEIGHT));
weight.setText("" + Weight);
final String Color = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_COLORS));
color.setText("" + Color);
final String Dt = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_DISPLAYTYPE));
displaytype.setText("" + Dt);
final String ds = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_DISPLAYSIZE));
displaysize.setText("" + ds);
final String dr = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_RESOLUTION));
displayresolution.setText("" + dr);
final String PPI = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_PPI));
ppi.setText("" + PPI);
final String cardSlot = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_CARDSLOT));
cardslot.setText("" + cardSlot);
final String INTERNAL = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_INTERNAL));
internal.setText("" + INTERNAL);
final String CR = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_CAMERA));
cameraresolution.setText("" + CR);
final String FLASH = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_CAMERAFLASH));
flash.setText("" + FLASH);
final String FEATURES = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_FEATURES));
camerafeatures.setText("" + FEATURES);
final String VIDEO = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_VIDEO));
video.setText("" + VIDEO);
final String FFC = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_FRONTCAMERA));
frontfacingcamera.setText("" + FFC);
final String CHIPSET = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_CHIPSET));
chipset.setText("" + CHIPSET);
final String CPU = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_CPU));
cpu.setText("" + CPU);
final String GPU = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_GPU));
gpu.setText("" + GPU);
final String Memory = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_MEMORY));
ram.setText("" + Memory);
final String BATTERY = c.getString(c
.getColumnIndex(AllPhonesDatabase.KEY_BATTERY));
battery.setText("" + BATTERY);
}
只是从数据库中获取文本的一些简单代码，并没有设置它。 但是我得到了这个错误！
08-19 19:18:17.591: E/AndroidRuntime(7902): FATAL EXCEPTION: main
08-19 19:18:17.591: E/AndroidRuntime(7902): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.androidarabia.phones/com.androidarabia.big.BigSpecs}: android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 1
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2246)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2296)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.app.ActivityThread.access$700(ActivityThread.java:151)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1281)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.os.Handler.dispatchMessage(Handler.java:99)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.os.Looper.loop(Looper.java:137)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.app.ActivityThread.main(ActivityThread.java:5293)
08-19 19:18:17.591: E/AndroidRuntime(7902): at java.lang.reflect.Method.invokeNative(Native Method)
08-19 19:18:17.591: E/AndroidRuntime(7902): at java.lang.reflect.Method.invoke(Method.java:511)
08-19 19:18:17.591: E/AndroidRuntime(7902): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
08-19 19:18:17.591: E/AndroidRuntime(7902): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
08-19 19:18:17.591: E/AndroidRuntime(7902): at dalvik.system.NativeStart.main(Native Method)
08-19 19:18:17.591: E/AndroidRuntime(7902): Caused by: android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 1
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.database.AbstractCursor.checkPosition(AbstractCursor.java:424)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:136)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:50)
08-19 19:18:17.591: E/AndroidRuntime(7902): at com.androidarabia.big.BigSpecs.setuptext(BigSpecs.java:62)
08-19 19:18:17.591: E/AndroidRuntime(7902): at com.androidarabia.big.BigSpecs.onCreate(BigSpecs.java:50)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.app.Activity.performCreate(Activity.java:5250)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097)
08-19 19:18:17.591: E/AndroidRuntime(7902): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2210)
08-19 19:18:17.591: E/AndroidRuntime(7902): ... 11 more
谢谢，非常感谢您的帮助=）！
答案 0 :(得分：1)
您需要在查询后调用mCursor.moveToFirst（）方法。检查你是否在此行附近查询后执行此操作checkPosition（AbstractCursor.java:424）。
答案 1 :(得分：0)
您必须将光标移动到第一行才能从中读取。你有点为第一个查询做了这个，但不是第二个查询（例如它在mCursor = mDb.rawQuery(cursor, null);之后丢失）。
final Cursor cursor = /*...*/;
if (cursor.getCount() < 1){
// handle empty cursors somehow, e.g. no results
return;
}
cursor.moveToNext();
// or
cursor.moveToFirst();
答案 2 :(得分：0)
在从中访问数据之前检查光标
If(cursor!=null && cursor.moveToFirst())