[英]Show check mark in selected item of ListView
我正在嘗試創建一個語言選擇屏幕。 我有一個 ListView 並且我正在使用自定義適配器類。 選擇一個項目后,我想在項目中顯示一個勾號。 我的 ListView 有一個 TextView` 和一個 ImageView。 如何實現?
這是我已經嘗試過的。
任何答案和建議表示贊賞,提前致謝
public class customAdapter extends BaseAdapter {
String[] languages ;
Context mContext;
boolean isChecked = false;
public customAdapter(String[] languages, Context
mContext){
this.languages = languages;
this.mContext = mContext;
}
@Override
public int getCount() {
return languages.length;
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView,
ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater)
mContext.getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
View rowView=
inflater.inflate(
R.layout.content_lang_list,parent,false);
TextView lang_text = (TextView)
rowView.findViewById(R.id.text_select_lang);
final ImageView image_tick = (ImageView)
rowView.findViewById(R.id.image_tick);
lang_text.setText(languages[position]);
image_tick.setImageResource(R.drawable.ic_checked);
return rowView;
}
public class ChangeLang extends AppCompatActivity {
private ListView languageList;
String[] languages = {"English","Portuguese","Arabic"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cahnge_lang);
languageList = (ListView)
findViewById(R.id.language_list);
final customAdapter mAdapter = new customAdapter(
languages,this);
languageList.setAdapter(mAdapter);
languageList.setOnItemClickListener(
new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent,
View view, int position, long id) {
String selected = ((TextView)
view.findViewById(R.id.text_select_lang))
.getText().toString();
Object itemObject =parent.getAdapter()
.getItem(position);
LanguageSelect selectedLang =
(LanguageSelect)itemObject;
}
});
}
}
作為語言選擇屏幕,我假設您一次只需要選擇一項。 您已經添加了一個布爾成員isChecked;
但似乎沒有在任何地方使用。
您在這里需要的是一個 int 成員 - 例如selectedItemPosition
其初始值設置為 -1。
換句話說,替換
boolean isChecked = false;
和
int selectedItemPosition = -1;
將此添加到onItemClick()
selectedItemPosition = ((selectedItemPosition!=position)?position:-1);
notifyDataSetChanged();
將此添加到您的getView()
image_tick.setVisibility((selectedItemPosition=position)?View.VISIBLE:View.GONE);
ListViews
, 遵循視圖持有者模式來優化性能。convertView
來回收視圖。image_tick.setImageResource(R.drawable.ic_checked);
android:src="R.drawable.ic_checked"
在 XML 中。使用setVisibility(View.VISIBLE);
在被點擊的圖像項目中! IE:
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View rowView= inflater.inflate(R.layout.content_lang_list,parent,false);
TextView lang_text = (TextView) rowView.findViewById(R.id.text_select_lang);
final ImageView image_tick = (ImageView) rowView.findViewById(R.id.image_tick);
lang_text.setText(languages[position]);
image_tick.setImageResource(R.drawable.ic_checked);
image_tick.setVisibility(View.VISIBLE); //Show image
return rowView;
}
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