【发布时间】：2013-05-09 23:19:38
【问题描述】：
我对 java 和 android 编程非常陌生，因此，我的理解不是很扎实，因此，如果在这里能得到一些帮助，我将非常感激。
我想提供一个选项，允许最终用户使用微调器更改主题。但是，当我运行该应用程序时，它在启动时失败。 该应用的主要活动如下：
public class ReminderListActivity extends ListActivity implements OnItemClickListener
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Utils.onActivityCreateSetTheme(this); //For applying a theme
setContentView(R.layout.reminder_list);
Spinner spin = (Spinner) findViewById(R.id.spinner2);
ArrayAdapter<String> aa = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,
themes);
spin.setAdapter(aa);
spin.OnItemClickListener(this); //-->unable to call onItemClick method.
}
@Override
public void OnItemClick(AdapterView<?> parent, View view, int position, long arg3) {
// TODO Auto-generated method stub
switch(view.getId())
{
case 0:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
break;
case 1:
Utils.changeToTheme(this, Utils.THEME_WHITE);
break;
case 2:
Utils.changeToTheme(this, Utils.THEME_BLUE);
break;
default:
Utils.changeToTheme(this, Utils.THEME_WHITE);
break;
}
}
Utils类如下：
private static int sTheme;
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
/**
* Set the theme of the Activity, and restart it by creating a new Activity
* of the same type.
*/
public static void changeToTheme(Activity activity, int theme)
{
sTheme = theme;
activity.finish();
activity.startActivity(new Intent(activity, activity.getClass()));
}
/** Set the theme of the activity, according to the configuration. */
public static void onActivityCreateSetTheme(Activity activity)
{
switch (sTheme)
{
default:
case THEME_DEFAULT:
break;
case THEME_WHITE:
activity.setTheme(R.style.Theme_White);
break;
case THEME_BLUE:
activity.setTheme(R.style.Theme_Blue);
break;
}
}
添加到初始问题：
我已将 onItemClickListener 更改为 OnItemSelectedListener。现在应用程序没有崩溃，但是当它加载时，屏幕一直在闪烁。
代码如下：
public class ReminderListActivity extends ListActivity implements OnItemSelectedListener
{
private static final int ACTIVITY_CREATE=0;
private static final int ACTIVITY_EDIT=1;
private RemindersDbAdapter mDbHelper;
String[] themes = { "Default", "White", "Blue"};
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Utils.onActivityCreateSetTheme(this); //For applying a theme
setContentView(R.layout.reminder_list);
mDbHelper = new RemindersDbAdapter(this);
mDbHelper.open();
fillData();
registerForContextMenu(getListView());
Spinner spin = (Spinner) findViewById(R.id.spinner2);
ArrayAdapter<String> aa = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,
themes);
spin.setAdapter(aa);
//spin.setOnItemSelectedListener(this);//-->problem here unable to call onItemClick method.
//What is image adapter
}
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
switch(arg1.getId())
{
case 0:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
break;
case 1:
Utils.changeToTheme(this, Utils.THEME_WHITE);
break;
case 2:
Utils.changeToTheme(this, Utils.THEME_BLUE);
break;
default:
Utils.changeToTheme(this, Utils.THEME_WHITE);
break;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
}
这是我的 LogCat
05-10 09:12:56.449: E/Trace(1004): error opening trace file: No such file or directory (2)
05-10 09:12:59.369: D/dalvikvm(1004): GC_CONCURRENT freed 180K, 11% free 2675K/2984K, paused 86ms+10ms, total 242ms
05-10 09:12:59.369: D/dalvikvm(1004): WAIT_FOR_CONCURRENT_GC blocked 61ms
05-10 09:12:59.403: I/dalvikvm-heap(1004): Grow heap (frag case) to 3.342MB for 635812-byte allocation
05-10 09:12:59.529: D/dalvikvm(1004): GC_FOR_ALLOC freed 59K, 11% free 3236K/3608K, paused 120ms, total 121ms
05-10 09:12:59.609: D/dalvikvm(1004): GC_FOR_ALLOC freed <1K, 11% free 3236K/3608K, paused 57ms, total 58ms
05-10 09:12:59.622: I/dalvikvm-heap(1004): Grow heap (frag case) to 3.760MB for 500416-byte allocation
05-10 09:12:59.779: D/dalvikvm(1004): GC_FOR_ALLOC freed <1K, 10% free 3724K/4100K, paused 152ms, total 152ms
05-10 09:13:00.039: D/dalvikvm(1004): GC_CONCURRENT freed 1K, 10% free 3728K/4100K, paused 33ms+96ms, total 261ms
05-10 09:13:00.799: I/Choreographer(1004): Skipped 33 frames! The application may be doing too much work on its main thread.
05-10 09:13:00.889: D/gralloc_goldfish(1004): Emulator without GPU emulation detected.
05-10 09:13:01.549: I/Choreographer(1004): Skipped 39 frames! The application may be doing too much work on its main thread.
05-10 09:13:03.999: D/dalvikvm(1004): GC_CONCURRENT freed 770K, 22% free 3405K/4356K, paused 97ms+30ms, total 339ms
05-10 09:13:03.999: D/dalvikvm(1004): WAIT_FOR_CONCURRENT_GC blocked 24ms
05-10 09:13:04.689: I/Choreographer(1004): Skipped 152 frames! The application may be doing too much work on its main thread.
05-10 09:13:05.899: I/Choreographer(1004): Skipped 68 frames! The application may be doing too much work on its main thread.
05-10 09:13:07.825: I/Choreographer(1004): Skipped 66 frames! The application may be doing too much work on its main thread.
05-10 09:13:10.030: I/Choreographer(1004): Skipped 70 frames! The application may be doing too much work on its main thread.
05-10 09:13:10.471: I/Choreographer(1004): Skipped 38 frames! The application may be doing too much work on its main thread.
05-10 09:13:11.510: I/Choreographer(1004): Skipped 32 frames! The application may be doing too much work on its main thread.
05-10 09:13:13.550: I/Choreographer(1004): Skipped 74 frames! The application may be doing too much work on its main thread.
05-10 09:13:14.040: I/Choreographer(1004): Skipped 37 frames! The application may be doing too much work on its main thread.
05-10 09:13:16.000: I/Choreographer(1004): Skipped 47 frames! The application may be doing too much work on its main thread.
05-10 09:13:16.530: I/Choreographer(1004): Skipped 50 frames! The application may be doing too much work on its main thread.
05-10 09:13:18.570: I/Choreographer(1004): Skipped 128 frames! The application may be doing too much work on its main thread.
05-10 09:13:20.809: D/dalvikvm(1004): GC_CONCURRENT freed 151K, 16% free 3668K/4344K, paused 80ms+36ms, total 434ms
05-10 09:13:21.170: I/Choreographer(1004): Skipped 99 frames! The application may be doing too much work on its main thread.
05-10 09:13:22.959: I/Choreographer(1004): Skipped 82 frames! The application may be doing too much work on its main thread.
05-10 09:13:24.149: I/Choreographer(1004): Skipped 50 frames! The application may be doing too much work on its main thread.
05-10 09:13:24.679: I/Choreographer(1004): Skipped 48 frames! The application may be doing too much work on its main thread.
05-10 09:13:27.719: I/Choreographer(1004): Skipped 75 frames! The application may be doing too much work on its main thread.
05-10 09:13:29.279: I/Choreographer(1004): Skipped 45 frames! The application may be doing too much work on its main thread.
05-10 09:13:31.061: I/Choreographer(1004): Skipped 84 frames! The application may be doing too much work on its main thread.
05-10 09:13:31.449: I/Choreographer(1004): Skipped 31 frames! The application may be doing too much work on its main thread.
05-10 09:13:33.880: I/Choreographer(1004): Skipped 37 frames! The application may be doing too much work on its main thread.
05-10 09:13:34.249: I/Choreographer(1004): Skipped 30 frames! The application may be doing too much work on its main thread.
05-10 09:13:36.230: D/dalvikvm(1004): GC_CONCURRENT freed 114K, 9% free 3939K/4308K, paused 47ms+69ms, total 832ms
05-10 09:13:37.539: I/Choreographer(1004): Skipped 75 frames! The application may be doing too much work on its main thread.
05-10 09:13:39.810: I/Choreographer(1004): Skipped 53 frames! The application may be doing too much work on its main thread.
05-10 09:13:40.970: I/Choreographer(1004): Skipped 41 frames! The application may be doing too much work on its main thread.
05-10 09:13:43.230: I/Choreographer(1004): Skipped 51 frames! The application may be doing too much work on its main thread.
05-10 09:13:43.672: I/Choreographer(1004): Skipped 39 frames! The application may be doing too much work on its main thread.
05-10 09:13:45.672: I/Choreographer(1004): Skipped 106 frames! The application may be doing too much work on its main thread.
05-10 09:13:47.770: I/Choreographer(1004): Skipped 87 frames! The application may be doing too much work on its main thread.
05-10 09:13:50.149: D/dalvikvm(1004): GC_CONCURRENT freed 116K, 6% free 4226K/4472K, paused 79ms+50ms, total 544ms
关于将监听器从 OnItemClickListener 更改为 OnSelectedItemListeher。该应用程序不会崩溃，但似乎正在跳帧。但是，如果不调用 onItemSelectedListener 方法，则应用程序可以正常运行。
应用加载“THEME_WHITE”。
添加到现有问题：
整个onCreate()方法如下图：
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Utils.onActivityCreateSetTheme(this); //For applying a theme
setContentView(R.layout.reminder_list);
mDbHelper = new RemindersDbAdapter(this);
mDbHelper.open();
fillData();
registerForContextMenu(getListView());
Spinner spin = (Spinner) findViewById(R.id.spinner2);
ArrayAdapter<String> aa = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,
themes);
spin.setAdapter(aa);
spin.setOnItemSelectedListener(this);
}
【问题讨论】：
-
查看我对您部分问题的回答。但是，您的 xml 中是否有
ListView和android:id="@android:id/list"？ -
是的，我有你提到的 ListView
标签： android switch-statement spinner onitemclicklistener onitemclick