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這顯示了其中包含列表視圖代碼的其中一個片段，它在其自己的佈局中工作，但在片段中不起作用。我應該怎麼做才能在片段中工作？我對android應用程序開發相當陌生，所以我不知道該怎麼做。如果你不明白我在做什麼，我讓用戶將數據輸入到表單中，然後我希望數據作爲列表顯示在片段中，以便他們可以查看從頭到尾輸入的所有數據。我一直在尋找解決方案，但我無法找到適合我需要的解決方案。我看到的所有信息都是預先保存的sq lite數據庫。當我從用戶獲取數據並將其保存到SQLite數據庫中時，我應該怎麼做才能使listview能夠在片段中工作
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.ListFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.database.Cursor;
import android.util.Log;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.widget.Toast;
import java.util.ArrayList;
import static android.R.attr.button;
public class tab3expense extends Fragment {
private static final String TAG = "tab3expense";
DatabaseHelper mDatabaseHelper;
private ListView mListView;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.tab3expense, container, false);
return rootView;
mListView = (ListView) findViewById(R.id.listView);
mDatabaseHelper = new DatabaseHelper(this);
populateListView();
}
private void populateListView() {
Log.d(TAG, "populateListView: Displaying data in the ListView.");
//get the data and append to a list
Cursor data = mDatabaseHelper.getData();
ArrayList<String> listData = new ArrayList<>();
while(data.moveToNext()){
//get the value from the database in column 1
//then add it to the ArrayList
listData.add(data.getString(1));
listData.add(data.getString(2));
listData.add(data.getString(3));
}
//create the list adapter and set the adapter
ListAdapter adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, listData);
mListView.setAdapter(adapter);
//set an onItemClickListener to the ListView
mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String name = adapterView.getItemAtPosition(i).toString();
Log.d(TAG, "onItemClick: You Clicked on " + name);
Cursor data = mDatabaseHelper.getItemID(name); //get the id associated with that name
int itemID = -1;
while(data.moveToNext()){
itemID = data.getInt(0);
}
if(itemID > -1){
Log.d(TAG, "onItemClick: The ID is: " + itemID);
Intent editScreenIntent = new Intent(tab3expense.this, add_expense.class);
editScreenIntent.putExtra("id",itemID);
editScreenIntent.putExtra("name",name);
startActivity(editScreenIntent);
}
else{
toastMessage("No ID associated with that name");
}
}
});
}
/**
* customizable toast
* @param message
*/
private void toastMessage(String message){
Toast.makeText(this,message, Toast.LENGTH_SHORT).show();
}
}
這裏是佈局文件
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.dharquissandas.budget.MainActivity$PlaceholderFragment">
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/listView"/>
</LinearLayout>
只是爲了澄清..告訴我你沒有得到任何編譯錯誤後*返回rootView; *在* onCreateView *行？ – Raghavendra
我在這一行收到一個錯誤：Intent editScreenIntent = new Intent（tab3expense.this，add_expense.class）; –