我有一个自定义Listview，其中包含节标题。当用户点击搜索时，列表必须加载。列表正在加载，但是当我向下滚动列表视图时它会崩溃。我也使用了观察者。但我不知道如何解决它。
我的主要活动是：
DataTable.Select(File.Exists(ColumnsName))
我的适配器getView方法是：
private void loadVolleyData(String url) {
String tag_json_obj = "json_obj_req";
final ProgressDialog pDialog = new ProgressDialog(this);
pDialog.setMessage("Loading...");
pDialog.show();
imageList1.clear();
imageList2.clear();
imageList3.clear();
imageList4.clear();
imageList5.clear();
imageList6.clear();
imageList7.clear();
imageList8.clear();
imageList9.clear();
Log.d(TAG, "Search URL: " + url);
JsonObjectRequest jsonObjReq = new JsonObjectRequest(url, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
Log.d(TAG, "Response Full: " + response);
try {
// One --------
JSONArray categoryval = response.getJSONArray("allbrands");
for (int j = 0; j < categoryval.length(); j++) {
allbrands = new HomeItem();
JSONObject object1 = categoryval.getJSONObject(j);
if (object1.getString("Status").equalsIgnoreCase("Success")) {
System.out.println("array" + object1.getString("imagepath"));
allbrands.setID(object1.getString("brandId"));
allbrands.setDesc(object1.getString("brandName"));
allbrands.setImage(object1.getString("imagepath"));
allbrands.setTag("ALL BRANDS");
imageList1.add(allbrands);
}
}
// Two ---------
JSONArray deals = response.getJSONArray("dealsnoffers");
System.out.println("Deals n Offres Array " + deals);
for (int k = 0; k < deals.length(); k++) {
allbrands = new HomeItem();
JSONObject object1 = deals.getJSONObject(k);
if (object1.getString("Status").equalsIgnoreCase("Success")) {
allbrands.setID(object1.getString("brandId"));
//allbrands.setName(object1.getString("brandName"));
allbrands.setImage(object1.getString("imagepath"));
allbrands.setDesc(object1.getString("desc"));
allbrands.setContent(object1.getString("content"));
allbrands.setTag("DEALS & OFFERS");
imageList2.add(allbrands);
}
}
// Three ----------
JSONArray Specials = response.getJSONArray("brandchildphotoimages");
System.out.println("Brand Child Pic Images" + Specials);
for (int k = 0; k < Specials.length(); k++) {
allbrands = new HomeItem();
JSONObject cuisine = Specials.getJSONObject(k);
if (cuisine.getString("Status").equalsIgnoreCase("Success")) {
allbrands.setID(cuisine.getString("brandId"));
//allbrands.setPhotoid(cuisine.getString("photoId"));
allbrands.setImage(cuisine.getString("imagepath"));
allbrands.setDesc(cuisine.getString("desc"));
allbrands.setContent(cuisine.getString("content"));
allbrands.setTag("MY SPECIALS");
imageList3.add(allbrands);
}
}
savngDataInList();
} catch (JSONException e) {
VolleyLog.e(TAG, "Response Handling: " + e);
}
pDialog.hide();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.d(TAG, "Response Error: " + error);
pDialog.hide();
}
});
jsonObjReq.setRetryPolicy(new DefaultRetryPolicy(
5000,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
// Adding request to request queue
AppController.getInstance().addToRequestQueue(jsonObjReq, tag_json_obj);
}
我的LogCat是
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
final MyViewHolder viewHolder = new MyViewHolder();
try {
final HomeItem HomeItem = HomeItemList.get(position);
final HomeItem HomeItem1 = HomeItemList1.get(position);
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.all_brands_layout_search, null);
viewHolder.imageOne = (DynamicHeightImageView) convertView.findViewById(R.id.my_brand_pinrest_view);
viewHolder.descOne = (TextView) convertView.findViewById(R.id.bugket_textView);
viewHolder.imageTwo = (DynamicHeightImageView) convertView.findViewById(R.id.my_brand_pinrest_view2);
viewHolder.descTwo = (TextView) convertView.findViewById(R.id.bugket_textView2);
convertView.setTag(viewHolder);
}
if (imageLoader == null)
imageLoader = AppController.getInstance().getImageLoader();
viewHolder.descOne.setText(HomeItem.getDesc());
//CatTitle.setText(HomeItem.getHomeItemDescription());
System.out.println("adapterrr" + HomeItem.getDesc());
imageLoader.get(HomeItem.getImage(), new ImageListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e("TAG_image", "Image Load Error: " + error.getMessage());
}
@Override
public void onResponse(ImageContainer response, boolean arg1) {
if (response.getBitmap() != null) {
// load image into imageview
viewHolder.imageOne.setImageBitmap(response.getBitmap());
}
}
});
System.out.println("adapterrr" + HomeItem.getImage());
viewHolder.descTwo.setText(HomeItem1.getDesc());
//CatTitle.setText(HomeItem.getHomeItemDescription());
System.out.println("adapterrr" + HomeItem1.getDesc());
imageLoader.get(HomeItem1.getImage(), new ImageListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e("TAG_image", "Image Load Error: " + error.getMessage());
}
@Override
public void onResponse(ImageContainer response, boolean arg1) {
if (response.getBitmap() != null) {
// load image into imageview
viewHolder.imageTwo.setImageBitmap(response.getBitmap());
}
}
});
// imageLoader.DisplayImage(HomeItem1.getImage(), CatImage1);
System.out.println("adapterrr" + HomeItem1.getImage());
} catch (Exception e) {
e.printStackTrace();
}
return convertView;
}
activity_main.xml是
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.truetech.lola, PID: 22344
java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getImportantForAccessibility()' on a null object reference
at android.widget.AbsListView.obtainView(AbsListView.java:2363)
at android.widget.ListView.makeAndAddView(ListView.java:1875)
at android.widget.ListView.fillDown(ListView.java:702)
at android.widget.ListView.fillGap(ListView.java:666)
at android.widget.AbsListView.trackMotionScroll(AbsListView.java:5036)
at android.widget.AbsListView$FlingRunnable.run(AbsListView.java:4584)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:603)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Handler.handleCallback(Handler.java:746)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
03-02 12:34:39.500 22344-22375/com.truetech.lola D/Volley: [10331] BasicNetwork.logSlowRequests: HTTP response for request=<[ ] http://166.62.88.68:8080/lolaPrjct/repo/photoimages/342.jpg 0x9d2d6d5b LOW 18> [lifetime=9981], [size=1030852], [rc=200], [retryCount=1]
和all_brands_search.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">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="@color/header_grey"
android:orientation="horizontal"
android:weightSum="100">
<ImageView
android:id="@+id/slidedrawer"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_weight="20"
android:contentDescription="@string/showmy"
android:padding="12dp"
android:src="@drawable/actionbar_back" />
<TextView
android:id="@+id/title_text"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginEnd="6dp"
android:layout_marginStart="6dp"
android:layout_weight="60"
android:text="@string/app_name_search"
android:textAllCaps="true"
android:textColor="@color/dark_red"
android:textStyle="bold" />
<ImageView
android:id="@+id/lolahomelick"
android:layout_width="0dp"
android:layout_height="38dp"
android:layout_gravity="center"
android:layout_weight="20"
android:padding="8dp"
android:src="@drawable/lola_home" />
</LinearLayout>
<LinearLayout
android:id="@+id/layout_search"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginTop="10dp"
android:background="@drawable/rounded_border_search"
android:orientation="horizontal"
android:weightSum="100">
<EditText
android:id="@+id/search_edittext"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:layout_gravity="center"
android:layout_weight="95"
android:background="@drawable/edittext_noborder"
android:gravity="center"
android:hint="Enter your search..."
android:maxLines="1"
android:textColorHint="@color/grey_grey"
android:textStyle="italic" />
<ImageView
android:id="@+id/action_search"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_gravity="center"
android:layout_marginRight="2dp"
android:layout_weight="5"
android:src="@drawable/searchgry" />
</LinearLayout>
<ListView
android:id="@+id/Listview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_marginTop="5dp"
android:divider="@null" />
<!--<GridView
android:id="@+id/gridView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_marginTop="5dp"
android:numColumns="2"
android:divider="@null" />-->
</LinearLayout>
更新了适配器类
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/rounded_border"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:weightSum="2"
android:orientation="horizontal">
<LinearLayout
android:id="@+id/itemContainer"
android:layout_width="0dip"
android:layout_height="210dp"
android:layout_margin="5dp"
android:layout_weight="1"
android:orientation="vertical"
android:tag="1">
<com.etsy.android.grid.util.DynamicHeightImageView
android:id="@+id/my_brand_pinrest_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="2dp"
android:scaleType="centerCrop" />
<TextView
android:id="@+id/bugket_textView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_gravity="center"
android:layout_marginBottom="5dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="5dp"
android:layout_weight="4"
android:gravity="center"
android:text=""
android:textColor="@color/red" />
</LinearLayout>
<LinearLayout
android:id="@+id/itemContainer2"
android:layout_width="0dip"
android:layout_height="210dp"
android:layout_margin="5dp"
android:layout_weight="1"
android:orientation="vertical"
android:tag="2">
<com.etsy.android.grid.util.DynamicHeightImageView
android:id="@+id/my_brand_pinrest_view2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="2dp"
android:scaleType="centerCrop" />s
<TextView
android:id="@+id/bugket_textView2"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_gravity="center"
android:layout_marginBottom="5dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="5dp"
android:layout_weight="4"
android:gravity="center"
android:text=""
android:textColor="@color/red" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
答案 0 :(得分：1)
你需要在设置标签之后得到那个viewHolder，你不这样做。请输入此代码并检查..
MyViewHolder viewHolder = null;
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
viewHolder = new MyViewHolder();;
convertView = inflater.inflate(R.layout.all_brands_layout_search, null);
viewHolder.imageOne = (DynamicHeightImageView) convertView.findViewById(R.id.my_brand_pinrest_view);
viewHolder.descOne = (TextView) convertView.findViewById(R.id.bugket_textView);
viewHolder.imageTwo = (DynamicHeightImageView) convertView.findViewById(R.id.my_brand_pinrest_view2);
viewHolder.descTwo = (TextView) convertView.findViewById(R.id.bugket_textView2);
convertView.setTag(viewHolder);
}else{
viewHolder= (MyViewHolder)convertView.getTag();
}
答案 1 :(得分：0)
您错误地使用了ViewHolder模式。你需要做那样的事情：
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
final MyViewHolder viewHolder;
final HomeItem HomeItem = HomeItemList.get(position);
final HomeItem HomeItem1 = HomeItemList1.get(position);
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.all_brands_layout_search, parent, false);
viewHolder = new MyViewHolder();
viewHolder.imageOne = (DynamicHeightImageView) convertView.findViewById(R.id.my_brand_pinrest_view);
viewHolder.descOne = (TextView) convertView.findViewById(R.id.bugket_textView);
viewHolder.imageTwo = (DynamicHeightImageView) convertView.findViewById(R.id.my_brand_pinrest_view2);
viewHolder.descTwo = (TextView) convertView.findViewById(R.id.bugket_textView2);
convertView.setTag(viewHolder);
} else {
viewHolder = (MyViewHolder)convertView.getTag();
}
///rest of your code
return convertView;
}
答案 2 :(得分：0)
你错了..如果你的视图为null，那么你创建新的ViewHolder，如果没有，那么你就可以从中获取ViewHolder。
<span>