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我試圖通過擴展的ArrayList圖片列表視圖適配器
創建一個自定義列表視圖適配器，當我做下面的我不能夠從URL獲取圖片，並在列表視圖中顯示，但它顯示默認圖像從XML
Item.java
public class Item {
String itemTitle = "", itemTimestamp = "", itemDescription = "", itemImage ="";
public Item(String itemTitle, String itemTimestamp, String itemDescription,
String itemImage) {
this.itemTitle = itemTitle;
this.itemDescription = itemDescription;
this.itemTimestamp = itemTimestamp;
this.itemImage = itemImage;
}
public String getItemTitle() {
return itemTitle;
}
public void setItemTitle(String itemTitle) {
this.itemTitle = itemTitle;
}
public String getItemTimestamp() {
return itemTimestamp;
}
public void setItemTimestamp(String itemTimestamp) {
this.itemTimestamp = itemTimestamp;
}
public String getItemDescription() {
return itemDescription;
}
public void setItemDescription(String itemDescription) {
this.itemDescription = itemDescription;
}
public String getItemImage() {
return itemImage;
}
public void setItemImage(String itemImage) {
this.itemImage = itemImage;
}
}
ListAdapter.java
public class ListAdapter extends ArrayAdapter<Item> {
public ListAdapter(Context context, int textViewResourceId) {
super(context, textViewResourceId);
// TODO Auto-generated constructor stub
}
private List<Item> items;
public ListAdapter(Context context, int resource, List<Item> items) {
super(context, resource, items);
this.items = items;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi;
vi = LayoutInflater.from(getContext());
v = vi.inflate(R.layout.list_item_default, null);
}
Item p = items.get(position);
if (p != null) {
TextView list_title = (TextView) v.findViewById(R.id.list_title);
TextView list_description = (TextView) v
.findViewById(R.id.list_description);
TextView list_timestamp = (TextView) v
.findViewById(R.id.list_timestamp);
ImageView list_image = (ImageView) v.findViewById(R.id.list_image);
if (list_title != null) {
list_title.setText(p.getItemTitle());
}
if (list_description != null) {
list_description.setText(p.getItemDescription());
}
if (list_timestamp != null) {
list_timestamp.setText(p.getItemTimestamp());
}
if (list_image != null) {
Uri imageURI = Uri.parse(p.getItemImage());
list_image.setImageURI(imageURI);
}
}
return v;
}
}
MessageActivity.java
public class MessagesActivity extends Activity {
ListView listview;
static ArrayList<Item> dataArray = new ArrayList<Item>();
static ArrayList<Item> contentArray = new ArrayList<Item>();
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_messages);
setupViews();
try {
contentArray = generateArray(createJson());
Log.d("bMobile", createJson());
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Log.d("bMobile", "start ListAdapter");
listview.setAdapter(new ListAdapter(MessagesActivity.this, R.layout.list_item_default,
contentArray));
Log.d("bMobile", "end ListAdapter");
}
public void setupViews() {
listview = (ListView) findViewById(R.id.list_items);
((TextView) findViewById(R.id.title_text))
.setText(R.string.description_messages);
}
// It creates a JSON and returns JSON string
public String createJson() throws JSONException {
JSONArray itemArray = new JSONArray();
JSONObject itemObject1 = new JSONObject();
itemObject1.put("title", "Harsha MV");
itemObject1.put("timestamp", "2 hours");
itemObject1.put("description", "Bangalore, India");
itemObject1.put("display_photo", "http://i.imgur.com/enUZr.jpg");
JSONObject itemObject2 = new JSONObject();
itemObject2.put("title", "Avinash G");
itemObject2.put("timestamp", "4 days");
itemObject2.put("description", "Mysore, India");
itemObject2.put("display_photo",
"http://imgn.dt07.net/1077/1077092_b.jpg");
JSONObject itemObject3 = new JSONObject();
itemObject3.put("title", "Jyosna Sahoo");
itemObject3.put("timestamp", "1 year");
itemObject3.put("description", "Rourkela, India");
itemObject3.put("display_photo",
"http://imgn.dt07.net/1099/1099091_b.jpg");
itemArray.put(itemObject1);
itemArray.put(itemObject2);
itemArray.put(itemObject3);
return itemArray.toString();
}
public ArrayList<Item> generateArray(String JSONdata) throws JSONException {
JSONArray listData = new JSONArray(JSONdata);
for (int i = 0; i < listData.length(); i++) {
JSONObject listObject = listData.getJSONObject(i);
String item_title = listObject.getString("title");
String item_timestamp = listObject.getString("timestamp");
String item_description = listObject.getString("description");
String item_image = listObject.getString("display_photo");
Item ObjectItem = new Item(item_title, item_description,
item_timestamp, item_image);
dataArray.add(ObjectItem);
}
return dataArray;
}
}
activity_messages.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="vertical" >
<LinearLayout
android:id="@+id/title_container"
style="@style/TitleBar" >
<ImageButton
style="@style/TitleBarAction"
android:contentDescription="@string/description_home"
android:onClick="onHomeClick"
android:src="@drawable/ic_title_home" />
<ImageView style="@style/TitleBarSeparator" />
<TextView
android:id="@+id/title_text"
style="@style/TitleBarText" />
<ImageView style="@style/TitleBarSeparator" />
<ImageButton
android:id="@+id/btn_title_refresh"
style="@style/TitleBarAction"
android:contentDescription="@string/description_refresh"
android:onClick="onRefreshClick"
android:src="@drawable/ic_title_refresh" />
<ProgressBar
android:id="@+id/title_refresh_progress"
style="@style/TitleBarProgressIndicator"
android:visibility="gone" />
</LinearLayout>
<ListView
android:id="@+id/list_items"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
<TextView
android:id="@+id/android:empty"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="@string/list_empty_visitors" />
</LinearLayout>
list_item_default.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="vertical" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<ImageView
android:id="@+id/list_image"
android:layout_width="64dip"
android:layout_height="64dip"
android:layout_alignParentLeft="true"
android:layout_marginRight="8dip"
android:background="@drawable/profile" >
</ImageView>
<LinearLayout
android:id="@+id/linearLayout2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_toRightOf="@+id/list_image"
android:orientation="vertical" >
<RelativeLayout
android:id="@+id/relativeLayout2"
android:layout_width="wrap_content"
android:layout_height="fill_parent" >
<TextView
android:id="@+id/list_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="@+id/list_timestamp"
android:ellipsize="end"
android:singleLine="true"
android:text="Harsha Mallikarjun Vantagudi"
android:textSize="@dimen/text_size_medium"
android:textStyle="bold" >
</TextView>
<TextView
android:id="@+id/list_timestamp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:padding="6dip"
android:paddingLeft="30dip"
android:singleLine="true"
android:text="2 hours"
android:textSize="@dimen/text_size_xxsmall" >
</TextView>
</RelativeLayout>
<TextView
android:id="@+id/list_description"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ellipsize="end"
android:singleLine="true"
android:text="Bangalore, India Bangalore, India Bangalore, India Bangalore, India"
android:textSize="@dimen/text_size_small" >
</TextView>
</LinearLayout>
</RelativeLayout>
</LinearLayout>
只是明顯的問題：你確定你的數組列表產生出來的JSON不是null？ –
是的，當我嘗試登錄時，我正在獲取JSON。猜猜之間獲取JSON和轉換爲陣列之間的一些問題..我想 –