Question

它在getBaseContext（）的代码行中显示错误。我不知道这里发生了什么我尝试了数组适配器而不是简单的适配器，但它显示错误。现在我正在使用简单的适配器..它给我错误..

  SimpleAdapter(getBaseContext(), aList, R.layout.list,          
       from, to);

headFragment.java

  public class HeadFragment extends ListFragment {
OnHeadlineSelectedListener mCallback;

// The container Activity must implement this interface so the fragment can deliver 
   messages
public interface OnHeadlineSelectedListener {
    /** Called by HeadlinesFragment when a list item is selected */
    public void onArticleSelected(int position);
}
static String[] Headlines = {
    "Article One",
    "Article Two",
    "Article 3"
};
int[] flags = new int[]{
        R.drawable.ic_11,
        R.drawable.ic_12,
        R.drawable.ic_13

    };
String[] currency = new String[]{
        "Indian Rupee",
        "Pakistani Rupee",
        "Sri Lankan Rupee",

    };

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setHasOptionsMenu(true);


 // Each row in the list stores country name, currency and flag
    List<HashMap<String,String>> aList = new ArrayList<HashMap<String,String>>();        

    for(int i=0;i<10;i++){
        HashMap<String, String> hm = new HashMap<String,String>();
        hm.put("txt", "Headlines: " + Headlines[i]);
        hm.put("cur","Currency : " + currency[i]);
        hm.put("flag", Integer.toString(flags[i]) );            
        aList.add(hm);        
    }

    // Keys used in Hashmap
    String[] from = { "flag","txt","cur" };

    // Ids of views in listview_layout
    int[] to = { R.id.flag,R.id.txt,R.id.cur};        

    // Instantiating an adapter to store each items

    SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), aList, R.layout.list,          
       from, to);
    // Getting a reference to listview of main.xml lagetBayout file
    ListView listView =( ListView ) findViewById(R.id.listview);

    // Setting the adapter to the listView
    listView.setAdapter(adapter);      }

list.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
 >
<ImageView
    android:id="@+id/flag"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"

    android:paddingTop="10dp"
    android:paddingRight="10dp"
    android:paddingBottom="10dp"
/>

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
>
    <TextView
        android:id="@+id/txt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="15dp"
    />

    <TextView
        android:id="@+id/cur"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="10dp"
    />
     <!-- Rightend Arrow -->
 <ImageView android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/next"
    android:layout_alignParentRight="true"
    android:layout_centerVertical="true"/>

</LinearLayout>
   </LinearLayout>

Answer 1

使用getApplicationContext()或Frgment context ..

Answer 2

getBaseContext()使用getActivity()或getApplicationContext()

getApplicationContext() 应用程序上下文与Applicaiton相关联，并且在整个生命周期中始终相同

不应该使用

getBasecontext() jst使用Context而不是与活动相关联的Context，并且可能在活动被销毁时被销毁

Fragment中的

getActivity() 返回Fragment与之关联的活动的上下文。

Answer 3

@Abhay您的代码没有问题只需要使用 getApplicationContext（）而不是 getBaseContext（），我完全同意@DhavalSodhaParmar

要了解更多信息，请阅读 getBaseContext（）和 getApplicationContext（）

之间的区别

在Android中列出带有图标，标题和说明的视图

3 个答案: