使用自定義適配器的ListFragment

Question

我在我的項目中設置了listfragment。但似乎我的片段無法通過我的適配器正確完成。其原因是Context context在MyListAdapter。如果我點擊糾正它。它變爲MenuFragment menuFragment。但是在更改之後，MyListAdapter出現錯誤。所以我糾正它。它變爲Context context。如果我糾正它，它仍然繼續下去。它的循環就是這樣。

注意：我想實現的是帶圖標的ListFragment。像我之前的其他問題（但不幸的是沒有人回答）。

public class MenuFragment extends ListFragment { 


@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
    return super.onCreateView(inflater, container, savedInstanceState); 
    } 

@Override 
public void onActivityCreated(Bundle savedInstanceState) { 
    super.onActivityCreated(savedInstanceState); 

    String [] proMenu ={ "Homies", "Best Nearby", "Coupon" , "Profile" , "History" , "", "Setting" , 
       "About" , "Sign Out"}; 

    setListAdapter(new MyListAdapter(this, proMenu)); 

} 

@Override 
public void onListItemClick(ListView lv, View v, int position, long id) { 
    Fragment newContent = null; 
    switch (position) { 
    case 0: 
     newContent = new ColorFragment(); 
     break; 
    case 1: 
     Intent intent7 = new Intent(); 
     intent7.setClass(getActivity(), Home.class); 
     intent7.putExtra("index", position); 
     startActivity(intent7); 
     break; 

編輯：這是我的佈局。它現在完美無瑕。我只需要調整textview和線性佈局，這樣一個字就不會減半。但我面臨着另一個問題。它就像背景圖像堆疊起來一樣。這是我的佈局上的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="50dp" 
android:orientation="horizontal" 
android:cacheColorHint="#00000000" 
android:background="@drawable/menu_drawer"> 

<ImageView 
    android:id="@+id/row_icon" 
    android:layout_width="50dp" 
    android:layout_height="50dp" 
    android:padding="10dp" 
    android:src="@drawable/ic_launcher" /> 

<TextView 
    android:id="@+id/row_title" 
    android:layout_width="0dp" 
    android:layout_height="match_parent" 
    android:layout_weight="1" 
    android:gravity="center_vertical" 
    android:padding="10dp" 
    android:text="Medium Text" 
    android:textSize="20dp" 
    android:textAppearance="@android:style/TextAppearance.Medium" /> 

</LinearLayout> 

如果我刪除此android:background="@drawable/menu_drawer"從linear layout。這將是完美的背景。沒有彼此堆放。但是當我在列表中滑動時，背景變得瘋狂，它消失了，並顯示出一些黑色背景。它像列表視圖android:cacheColorHint="#00000000"的問題一樣。我已經在linear layout中添加了cachecolor。但它仍然顯示出那些黑色背景。就像這樣。

我知道什麼這個問題的。因爲默認背景是黑色的。但我不知道如何解決它。

編輯2：黑色問題解決。

已解決。

Answer 1

您不會將有效的Context傳遞到您的適配器，Fragment不是 a Context。您需要使用，例如，Activity作爲Context：

setListAdapter(new MyListAdapter(getActivity(), proMenu)); 

我希望你們也實現適配器中getCount()方法，否則你不會看到任何ListView不管有多少個元素你有。

Answer 2

創建自定義適配器時，不要將「Context」對象作爲參考傳遞給Activity，只需將Activity對象傳遞給Custom Adaper即可。

public class HealthAdvice extends ListFragment { 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 

     View rootView = inflater.inflate(R.layout.health_advice, container, false); 

     return rootView; 

    } 

    @Override 
    public void onActivityCreated(Bundle savedInstanceState) { 
     super.onActivityCreated(savedInstanceState); 

     HealthAdviceArray health_data[] = new HealthAdviceArray[] 
       { 
       new HealthAdviceArray(R.drawable.ic_launcher, "Cloudy"), 
       new HealthAdviceArray(R.drawable.ic_launcher, "Showers"), 
       new HealthAdviceArray(R.drawable.ic_launcher, "Snow"), 
       new HealthAdviceArray(R.drawable.ic_launcher, "Storm"), 
       new HealthAdviceArray(R.drawable.ic_launcher, "Sunny") 
       }; 

     HealthAdviceAdapter adapter = new HealthAdviceAdapter(getActivity(), 
       R.layout.health_advice_item_row, health_data); 

     /** Setting the array adapter to the list view */ 
     setListAdapter(adapter); 

    } 

}// end main class HealthAdvice 

Answer 3

Following is the method to create listFragement list view: 
HealthAdvice.java 

package com.example.babs; 


import android.app.ListFragment; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 

public class HealthAdvice extends ListFragment { 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 

     View rootView = inflater.inflate(R.layout.health_advice, container, false); 

     return rootView; 

    } 

    @Override 
    public void onActivityCreated(Bundle savedInstanceState) { 
     super.onActivityCreated(savedInstanceState); 

     HealthAdviceArray health_data[] = new HealthAdviceArray[] 
       { 
       new HealthAdviceArray(R.drawable.ic_launcher, "Cloudy"), 
       new HealthAdviceArray(R.drawable.ic_launcher, "Showers"), 
       new HealthAdviceArray(R.drawable.ic_launcher, "Snow"), 
       new HealthAdviceArray(R.drawable.ic_launcher, "Storm"), 
       new HealthAdviceArray(R.drawable.ic_launcher, "Sunny") 
       }; 

     HealthAdviceAdapter adapter = new HealthAdviceAdapter(getActivity(), 
       R.layout.health_advice_item_row, health_data); 

     /** Setting the array adapter to the list view */ 
     setListAdapter(adapter); 

    } 

}// end main class HealthAdvice 

Step 2: 

HealthAdviceAdapter.java 
package com.example.babs; 

import android.app.Activity; 
import android.content.Context; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 
import android.widget.ImageView; 
import android.widget.TextView; 

public class HealthAdviceAdapter extends ArrayAdapter<HealthAdviceArray>{ 

    Context context; 
    int layoutResourceId;  
    HealthAdviceArray data[] = null; 

    public HealthAdviceAdapter(Context context, int layoutResourceId, HealthAdviceArray[] data) { 
     super(context, layoutResourceId, data); 
     this.layoutResourceId = layoutResourceId; 
     this.context = context; 
     this.data = data; 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     View row = convertView; 
     HealthAdviceArrayHolder holder = null; 

     if(row == null) 
     { 
      LayoutInflater inflater = ((Activity)context).getLayoutInflater(); 
      row = inflater.inflate(layoutResourceId, parent, false); 

      holder = new HealthAdviceArrayHolder(); 
      holder.imgIcon = (ImageView)row.findViewById(R.id.imgIcon); 
      holder.txtTitle = (TextView)row.findViewById(R.id.txtTitle); 

      row.setTag(holder); 
     } 
     else 
     { 
      holder = (HealthAdviceArrayHolder)row.getTag(); 
     } 

     HealthAdviceArray weather = data[position]; 
     holder.txtTitle.setText(weather.title); 
     holder.imgIcon.setImageResource(weather.icon); 

     return row; 
    } 

    static class HealthAdviceArrayHolder 
    { 
     ImageView imgIcon; 
     TextView txtTitle; 
    } 
} 

Step 3: 

HealthAdviceArray.java 

package com.example.babs; 


public class HealthAdviceArray { 

    public int icon; 
    public String title; 

    // we are over loading here 
    public HealthAdviceArray(){ 
     super(); 
    } 

    public HealthAdviceArray(int icon, String title) { 
     super(); 
     this.icon = icon; 
     this.title = title; 
    } 

} 

step 4: 

Health Advice health_advice.xml 

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:background="#FFFFFF" 
    android:orientation="vertical" > 

    <ListView 
     android:id="@android:id/list" 
     android:layout_width="fill_parent" 
     android:layout_height="fill_parent" /> 

</LinearLayout> 

step 5: 

Health Advice items: health_advice_item_row.xml 

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="horizontal" 
    android:padding="10dp" > 

    <ImageView 
     android:id="@+id/imgIcon" 
     android:layout_width="wrap_content" 
     android:layout_height="fill_parent" 
     android:layout_marginBottom="5dp" 
     android:layout_marginRight="15dp" 
     android:layout_marginTop="5dp" 
     android:contentDescription="@string/image_view" 
     android:gravity="center_vertical" /> 

    <TextView 
     android:id="@+id/txtTitle" 
     android:layout_width="fill_parent" 
     android:layout_height="fill_parent" 
     android:layout_marginBottom="5dp" 
     android:layout_marginTop="5dp" 
     android:gravity="center_vertical" 
     android:textColor="#000000" 
     android:textSize="22sp" 
     android:textStyle="bold" /> 

</LinearLayout>