根據(jù)需求,要實(shí)現(xiàn)NumberPicker的items動(dòng)態(tài)數(shù)量、內(nèi)容動(dòng)態(tài)變化。所以需要執(zhí)行以下代碼
mNumberPicker.setMaxValue(maxValue);
mNumberPicker.setDisplayedValues(displayedValues);
這里要需要注意的是setMaxValue进统。如果mNumberPicker對(duì)象原本的displayedValues數(shù)組lengths小于即將設(shè)置的maxValue助币。那么,執(zhí)行setMaxValue就會(huì)跑出數(shù)組下表越界( java.lang.ArrayIndexOutOfBoundsException)
相反麻昼,如果代碼順序?yàn)?
mNumberPicker.setDisplayedValues(displayedValues);
mNumberPicker.setMaxValue(maxValue);
那么奠支,這里需要注意setDisplayedValues。如果mNumberPicker對(duì)象原本的maxValue大于即將甚至的displayedValues數(shù)組的lengths,那么抚芦,執(zhí)行setDisplayedValues就會(huì)跑出數(shù)組下表越界( java.lang.ArrayIndexOutOfBoundsException)
避免java.lang.ArrayIndexOutOfBoundsException寫法示例:
mNp1.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
@Override
public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
List<String> cityList = initCity(mProvinceList.get(newVal).getP_code());
String[] cities = new String[cityList.size()];
for (int i = 0; i < cityList.size(); i++) {
cities[i] = cityList.get(i);
}
//重點(diǎn)這里
if (cities.length > mOldSize) {
mNp2.setDisplayedValues(cities);
mNp2.setMinValue(0);
mNp2.setMaxValue(cities.length - 1);
}else {
mNp2.setMinValue(0);
mNp2.setMaxValue(cities.length - 1);
mNp2.setDisplayedValues(cities);
}
mOldSize = cities.length;
}
});