我有一个 ListView ，其中的项目来自数据库。我试图将 listview 项目的图像图标放在 xml 中。但是，它没有显示图标。我尝试了很多方法，但似乎没有任何效果？
这是我的 ListView :
public class TypeMenu extends AppCompatActivity {
private String TAG = TypeMenu.class.getSimpleName();
String bid;
private ProgressDialog pDialog;
private ListView lv;
private static final String TAG_BID = "bid";
// URL to get contacts JSON
private static String url = "http://cloud....com/brtemp/index.php";
ArrayList<HashMap<String, String>> contactList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_type_menu);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
contactList = new ArrayList<>();
lv = (ListView) findViewById(R.id.list);
new GetContacts().execute();
// on seleting single product
// launching Edit Product Screen
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// getting values from selected ListItem
HashMap<String, String> selected = contactList.get(position);
String selectedId= selected.get("id");
Intent in = new Intent(getApplicationContext(), SubMenu.class);
// sending pid to next activity
in.putExtra("id",selectedId);
startActivityForResult(in, 100);
Toast.makeText(getApplicationContext(),"Toast" +selectedId ,Toast.LENGTH_SHORT).show();
}
});
}
/**
* Async task class to get json by making HTTP call
*/
private class GetContacts extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(TypeMenu.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
// Toast.makeText(getApplicationContext(),"Toast",Toast.LENGTH_LONG).show();
}
@Override
protected Void doInBackground(Void... arg0) {
HttpHandler sh = new HttpHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url);
Log.e(TAG, "Response from url: " + jsonStr);
if (jsonStr != null) {
try {
JSONArray jsonArry = new JSONArray(jsonStr);
for (int i = 0; i < jsonArry.length(); i++)
{
JSONObject c = jsonArry.getJSONObject(i);
String id = c.getString("id");
String type = c.getString("type");
HashMap<String, String> contact = new HashMap<>();
contact.put("id", id);
contact.put("type", type);
contactList.add(contact);
}
} catch (final JSONException e) {
Log.e(TAG, "Json parsing error: " + e.getMessage());
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Json parsing error: " + e.getMessage(),
Toast.LENGTH_LONG)
.show();
}
});
}
} else {
Log.e(TAG, "Couldn't get json from server.");
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Couldn't get json from server. Check LogCat for possible errors!",
Toast.LENGTH_LONG)
.show();
}
});
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
TypeMenu.this, contactList,
R.layout.list_item, new String[]{ "type","id"},
new int[]{
R.id.type,R.id.arrow1});
lv.setAdapter(adapter);
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
如果我在上面的代码中输入“R.id.Type, R.id.arrow1”，则列表不会打开并出现错误。
这是我的 Listview.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="wrap_content"
android:orientation="vertical"
>
<!-- Product id (pid) - will be DDEN - used to pass to other activity -->
<TextView
android:id="@+id/id"
android:layout_width="30dp"
android:layout_height="30dp"/>
<TextView
android:id="@+id/type"
android:textSize="20dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<ImageView
android:id="@+id/arrow1"
android:layout_width="match_parent"
android:layout_height="15dp"
android:layout_gravity="center"
android:layout_weight="3"
android:src="@drawable/dropdown" />
</LinearLayout>
这是我的日志:
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.zeba.broccoli, PID: 1231
android.content.res.Resources$NotFoundException: Resource ID #0x1
at android.content.res.Resources.getValue(Resources.java:2452)
at android.support.v7.widget.AppCompatDrawableManager.loadDrawableFromDelegates(AppCompatDrawableManager.java:330)
at android.support.v7.widget.AppCompatDrawableManager.getDrawable(AppCompatDrawableManager.java:195)
at android.support.v7.widget.AppCompatDrawableManager.getDrawable(AppCompatDrawableManager.java:188)
at android.support.v7.content.res.AppCompatResources.getDrawable(AppCompatResources.java:100)
at android.support.v7.widget.AppCompatImageHelper.setImageResource(AppCompatImageHelper.java:73)
at android.support.v7.widget.AppCompatImageView.setImageResource(AppCompatImageView.java:81)
at android.widget.SimpleAdapter.setViewImage(SimpleAdapter.java:262)
at android.widget.SimpleAdapter.bindView(SimpleAdapter.java:192)
at android.widget.SimpleAdapter.createViewFromResource(SimpleAdapter.java:126)
at android.widget.SimpleAdapter.getView(SimpleAdapter.java:114)
at android.widget.AbsListView.obtainView(AbsListView.java:2828)
at android.widget.ListView.measureHeightOfChildren(ListView.java:1292)
at android.widget.ListView.onMeasure(ListView.java:1204)
at android.view.View.measure(View.java:18870)
at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:464)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:703)
at android.support.design.widget.HeaderScrollingViewBehavior.onMeasureChild(HeaderScrollingViewBehavior.java:90)
at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onMeasureChild(AppBarLayout.java:1367)
at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:768)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1435)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:721)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:612)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1435)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:721)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:612)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:3076)
at android.view.View.measure(View.java:18870)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2392)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1416)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1661)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1301)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7016)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:777)
at android.view.Choreographer.doCallbacks(Choreographer.java:590)
at android.view.Choreographer.doFrame(Choreographer.java:560)
at android.view.Choreographer$FrameDisplayEventRec
I/Process: Sending signal. PID: 1231 SIG: 9
Application terminated.
最佳答案
@z.al 我理解你的情况，但为了让你确定，SimpleAdapter 只是帮助将字符串类型值填充到 ID 指定的 TextView 中。
但在您的情况下，您应该实现自定义 ArrayAdapter 并在 getView() 方法中将图像图标设置为 imageView。
以下是让您清楚的简单 fragment :
public class Person {
public HashMap<String, String> contact;
void Person(HashMap<String, String> contact) {
this.contact = contact;
}
}
public class MyListAdapter extends ArrayAdapter<Person> {
private Context context;
private ArrayList<Person> contactList;
private LayoutInflater mInflater;
private boolean mNotifyOnChange = true;
public MyListAdapter(Context context, ArrayList<Person> contactList) {
super(context, R.layout.my_row_layout);
this.context = context;
this.contactList = new ArrayList<>(contactList);
this.mInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return contactList.size();
}
@Override
public Person getItem(int position) {
return contactList.get(position);
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
if (convertView == null) {
holder = new ViewHolder();
convertView = mInflater.inflate(R.layout.my_row_layout,parent, false);
holder.name = (TextView) convertView.findViewById(R.id.textview_name);
holder.description = (TextView) convertView.findViewById(R.id.textview_description);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
Person person = contactList.get(position);
holder.name.setText(person.get("name"));
holder.image.setImageResource(person.get("id"));
holder.pos = position;
return convertView;
}
//---------------static views for each row-----------//
static class ViewHolder {
TextView name;
TextView description;
ImageView image;
int pos; //to store the position of the item within the list
}
}
关于android - 图像图标未显示在 Listview Android 中？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41561087/