由于以上user45678的回答,我写了这个
public class SpinnerNoDefault extends Spinner {
public void initialize(List<String> items) {
initialize(items, android.R.layout.simple_spinner_item, android.R.layout.simple_spinner_dropdown_item);
}
public void initialize(List<String> items, @LayoutRes int mItemResId, @LayoutRes int dropdownResId) {
List<String> itemsWithEmpty = new ArrayList<>(items);
itemsWithEmpty.add("");
String[] choicesArray = itemsWithEmpty.toArray(new String[itemsWithEmpty.size()]);
ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(getContext(), mItemResId, choicesArray) {
@NonNull
@Override
public View getView(int position, View convertView, @NonNull ViewGroup parent) {
View v = super.getView(position, convertView, parent);
if (position == getCount()) {
((TextView)v.findViewById(android.R.id.text1)).setText(null);
((TextView)v.findViewById(android.R.id.text1)).setHint(parent.getContext().getString(R.string.spinner_no_default_hint));
}
return v;
}
@Override
public int getCount() {
// Don't display last item. It is used as hint.
return super.getCount()-1;
}
};
spinnerArrayAdapter.setDropDownViewResource(dropdownResId);
setAdapter(spinnerArrayAdapter);
setSelection(itemsWithEmpty.size()-1);
}
}
空的意思你要设置 – Pavya
@ user3676184 - 空意味着“空”值或“无”字符串 – user45678
没有鲁斯塔姆,我不想清除我的名单,我只是想微调的默认值是空的,意味着价值将只一旦用户选择显示,直到这时微调将没有任何价值 – user45678