ListView中的Android setText导致空指针
这是我的问题,我想从ListView中设置文本。问题是,我会得到一个错误,因为(根据我的日志)我主要活动的setContentView与TextView不匹配,我想从另一个.xml(contactList.xml)设置文本。ListView中的Android setText导致空指针
Jobs Activity(Main在我ParseJobs方法)
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.jobs);
vib = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
TextView assigned = (TextView) findViewById(R.id.assigned);
new ParseJobs().execute();
ParseJobs()方法
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if (ACKNOWLEDGED.contains("False")) {
/** Updating parsed JSON data into ListView */
ListAdapter adapter = new SimpleAdapter(Jobs.this, contactList, R.layout.list_item, new String[] { job, pays, ready_at }, new int[] { R.id.job1, R.id.pays1, R.id.ready_at1 });
setListAdapter(adapter);
//TextView readyORdue = (TextView) findViewById(R.id.readyORdue);
//readyORdue.setText("Ready At:");
}
if (ACKNOWLEDGED.contains("True")) {
/** Updating parsed JSON data into ListView */
ListAdapter adapter = new SimpleAdapter(Jobs.this, contactList, R.layout.list_item, new String[] { job, pays, due_by }, new int[] { R.id.job1, R.id.pays1, R.id.due_by1 });
setListAdapter(adapter);
//TextView readyORdue = (TextView) findViewById(R.id.readyORdue);
//readyORdue.setText("Due By:");
}
VerifyDriver.dismiss();
}
}
注意,我试图更新的TextView “readyORdue”,而是因为,这TextView的属于SimpleAdapter contactList我会得到一个错误.xml
所以我的问题是,我将如何从我的contactList XML布局setText textview?
我的继承人日志:
07-17 15:55:16.703: W/dalvikvm(4387): threadid=1: thread exiting with uncaught exception (group=0x40015578)
07-17 15:55:16.703: E/AndroidRuntime(4387): FATAL EXCEPTION: main
07-17 15:55:16.703: E/AndroidRuntime(4387): java.lang.NullPointerException
07-17 15:55:16.703: E/AndroidRuntime(4387): at com.jetdelivery.mobile.Jobs$ParseJobs.onPostExecute(Jobs.java:287)
07-17 15:55:16.703: E/AndroidRuntime(4387): at com.jetdelivery.mobile.Jobs$ParseJobs.onPostExecute(Jobs.java:1)
07-17 15:55:16.703: E/AndroidRuntime(4387): at android.os.AsyncTask.finish(AsyncTask.java:417)
07-17 15:55:16.703: E/AndroidRuntime(4387): at android.os.AsyncTask.access$300(AsyncTask.java:127)
07-17 15:55:16.703: E/AndroidRuntime(4387): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429)
07-17 15:55:16.703: E/AndroidRuntime(4387): at android.os.Handler.dispatchMessage(Handler.java:99)
07-17 15:55:16.703: E/AndroidRuntime(4387): at android.os.Looper.loop(Looper.java:130)
07-17 15:55:16.703: E/AndroidRuntime(4387): at android.app.ActivityThread.main(ActivityThread.java:3687)
07-17 15:55:16.703: E/AndroidRuntime(4387): at java.lang.reflect.Method.invokeNative(Native Method)
07-17 15:55:16.703: E/AndroidRuntime(4387): at java.lang.reflect.Method.invoke(Method.java:507)
07-17 15:55:16.703: E/AndroidRuntime(4387): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
07-17 15:55:16.703: E/AndroidRuntime(4387): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
07-17 15:55:16.703: E/AndroidRuntime(4387): at dalvik.system.NativeStart.main(Native Method)
287线是 “readyORdue.setText(” 准备好: “);”
如上所述,如果您想使用另一个布局文件“contactList.xml”,首先需要对其进行充气。
LayoutInflater inflater = (LayoutInflater)context.getSystemService (Context.LAYOUT_INFLATER_SERVICE);
View contactList= inflater.inflate(R.layout.contactList, false);
现在
TextView readyORdue = (TextView)contactList.findViewById(R.id.readyORdue);
会给你所需要的TextView,你R.layout.jobs添加这种观点有些容器以使其可见。
感谢Maxim!有效 – 2012-07-17 23:19:23
setListAdapter东西与ListActivity和ListActivity有她自己的版面内容,所以......你不能在一个ListActivity的setContentView 你可以做的是建立自己的布局包含列表和TextView的readyORdue &的TextView分配 只是一件事你为什么使用两个if?你可以设置 如果(firstCondition){ .. }其他 ...
在同一个班是谁的?如果是这样,我会在MainActivity
中定义readyORdue
。如果您可以避免,您的线程不应该定义用户界面对象;这就是为什么你有onCreate()
。
public class MainActivity {
private TextView readyORDue;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.jobs);
vib = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
TextView assigned = (TextView) findViewById(R.id.assigned);
readyORDue = (TextView) findViewById(R.id.readyORdue);
new ParseJobs().execute();
}
}
然后在你的解析器
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if (ACKNOWLEDGED.contains("False")) {
/** Updating parsed JSON data into ListView */
ListAdapter adapter = new SimpleAdapter(Jobs.this, contactList, R.layout.list_item, new String[] { job, pays, ready_at }, new int[] { R.id.job1, R.id.pays1, R.id.ready_at1 });
setListAdapter(adapter);
readyORdue.setText("Ready At:");
}
if (ACKNOWLEDGED.contains("True")) {
/** Updating parsed JSON data into ListView */
ListAdapter adapter = new SimpleAdapter(Jobs.this, contactList, R.layout.list_item, new String[] { job, pays, due_by }, new int[] { R.id.job1, R.id.pays1, R.id.due_by1 });
setListAdapter(adapter);
readyORdue.setText("Due By:");
}
VerifyDriver.dismiss();
}
注意:你可能会使用runOnUiThread
您的setText()调用。
你能发布具有确切错误的LogCat吗? R.id.readyORdue - layout xml也有帮助 – Maxim 2012-07-17 22:54:05
我可以问一个问题吗?你为什么试图在onPostExecute中设置一个适配器,并在与你的UI线程不同的线程中创建一个适配器。认为它可能真的解决了! – Ahmed 2012-07-17 22:56:07
刚刚更新我的日志 – 2012-07-17 22:56:43