我应该首先注意到我对Android开发非常陌生，所以如果我的问题看起来很愚蠢，那就很抱歉。我试图在应用程序中查询我的SQLite数据库，以动态创建活动上的内容。这是我的数据库助手文件中的查询
public Cursor getWhereToEatActivity (int LocationId)
{
Cursor cursor = myDataBase.rawQuery("SELECT Location.locationId as _id,Location.title,Location.desc, location.address, location.hours, location.website, location.phone FROM " +
"TripWhereToEat JOIN Trip ON TripWhereToEat.tripId = Trip.tripId JOIN Location ON " +
"Location.locationId = TripWhereToEat.locationId where TripWhereToEat.tripId = ?",
new String[] {Integer.toString(LocationId)});
cursor.moveToFirst();
return cursor;
}
以下是选择项目的位置：
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {
LocationListitem locationItem = (LocationListitem)lvItems.getItemAtPosition(position);
int locationId = locationItem.getLocationId();
// Pass the ID into the next activity
Map<String, String> parms = new HashMap<String, String>();
parms.put("locationId", Integer.toString(locationId));
if (listType.equals("whattosee")) {
// switchActivity(WhatToSeeActivity.class, parms);
}
if (listType.equals("wheretostay")) {
// switchActivity(WhereToStayActivity.class, parms);
}
if (listType.equals("wheretoeat")) {
switchActivity(WhereToEatActivity.class, parms);
}
}
});
以下是活动切换到：
public class WhereToEatActivity extends FragmentActivityBase {
private int LocationId;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_where_to_eat);
AndroidApplication app = (AndroidApplication)getApplication();
DatabaseHelper myDbHelper = app.getDatabase(); // new DatabaseHelper(this);
LocationId = Integer.valueOf(this.getParam("LocationId"));
Cursor tripRecord = myDbHelper.getWhereToEatActivity(LocationId);
tripRecord.moveToFirst();
if (!tripRecord.isAfterLast()) {
String name = tripRecord.getString(tripRecord.getColumnIndex("title"));
String title = tripRecord.getString(tripRecord.getColumnIndex("desc"));
String image = tripRecord.getString(tripRecord.getColumnIndex("image"));
String address = tripRecord.getString(tripRecord.getColumnIndex("address"));
ImageView mainImageView = (ImageView)findViewById(R.id.image);
int resId = getResources().getIdentifier("com.integrativelogic.roadtrip:drawable/"+image, null, null);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),resId);
if (bitmap != null)
mainImageView.setImageBitmap (bitmap);
TextView nameView = (TextView)findViewById(R.id.name);
nameView.setText(name);
TextView titleView = (TextView)findViewById(R.id.title);
titleView.setText(Html.fromHtml(title));
titleView.setMovementMethod(LinkMovementMethod.getInstance());
TextView addressView = (TextView)findViewById(R.id.address);
addressView.setText(address);
}
tripRecord.close();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
这是我从Logcat得到的错误：
01-12 11:23:52.186: E/AndroidRuntime(15238): FATAL EXCEPTION: main
01-12 11:23:52.186: E/AndroidRuntime(15238): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.integrativelogic.roadtrip/com.integrativelogic.roadtrip.WhereToEatActivity}: java.lang.NumberFormatException: unable to parse '' as integer
01-12 11:23:52.186: E/AndroidRuntime(15238): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1821)
01-12 11:23:52.186: E/AndroidRuntime(15238): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1842)
01-12 11:23:52.186: E/AndroidRuntime(15238): at android.app.ActivityThread.access$1500(ActivityThread.java:132)
01-12 11:23:52.186: E/AndroidRuntime(15238): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1038)
01-12 11:23:52.186: E/AndroidRuntime(15238): at android.os.Handler.dispatchMessage(Handler.java:99)
01-12 11:23:52.186: E/AndroidRuntime(15238): at android.os.Looper.loop(Looper.java:150)
01-12 11:23:52.186: E/AndroidRuntime(15238): at android.app.ActivityThread.main(ActivityThread.java:4263)
01-12 11:23:52.186: E/AndroidRuntime(15238): at java.lang.reflect.Method.invokeNative(Native Method)
01-12 11:23:52.186: E/AndroidRuntime(15238): at java.lang.reflect.Method.invoke(Method.java:507)
01-12 11:23:52.186: E/AndroidRuntime(15238): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
01-12 11:23:52.186: E/AndroidRuntime(15238): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
01-12 11:23:52.186: E/AndroidRuntime(15238): at dalvik.system.NativeStart.main(Native Method)
01-12 11:23:52.186: E/AndroidRuntime(15238): Caused by: java.lang.NumberFormatException: unable to parse '' as integer
01-12 11:23:52.186: E/AndroidRuntime(15238): at java.lang.Integer.parseInt(Integer.java:362)
01-12 11:23:52.186: E/AndroidRuntime(15238): at java.lang.Integer.parseInt(Integer.java:332)
01-12 11:23:52.186: E/AndroidRuntime(15238): at java.lang.Integer.valueOf(Integer.java:506)
01-12 11:23:52.186: E/AndroidRuntime(15238): at com.integrativelogic.roadtrip.WhereToEatActivity.onCreate(WhereToEatActivity.java:27)
01-12 11:23:52.186: E/AndroidRuntime(15238): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1072)
01-12 11:23:52.186: E/AndroidRuntime(15238): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1785)
答案 0 :(得分：0)
因为您是新手我会在您的应用突然崩溃时解释一下调试过程：
第一部分是读取LogCat输出的最后几行：
引起：java.lang.NumberFormatException：无法解析＆＃39;＆＃39;作为整数
所以我们知道尝试使空字符串为整数是一个问题。您只能从包含数字的String中创建一个整数。
在Log下面的那几行，你会看到
at com.integrativelogic.roadtrip.WhereToEatActivity.onCreate（WhereToEatActivity.java:27）
所以我们知道它发生在你的WhereToEatActivity的第27行，我不会计算你在这里发布的内容，但我假设它是这一行
LocationId = Integer.valueOf(this.getParam("LocationId"));
因此我认为您可以安全地认为您遇到此错误的原因是因为没有参数＆＃34; LocationId＆＃34;或参数为空。
答案 1 :(得分：0)
你的错误就在这里：
Caused by: java.lang.NumberFormatException: unable to parse '' as integer
我怀疑你在这里有一个空位：
LocationId = Integer.valueOf(this.getParam("LocationId"));
如果在此处引用该行：
at com.integrativelogic.roadtrip.WhereToEatActivity.onCreate(WhereToEatActivity.java:27)