我需要在 Spinner
中选择第二个项目时显示 AlertDialog
。我知道使用 onItemSelected
我们可以收听微调器选择并显示弹出窗口。问题是当我选择第二个项目时,对话框出现,但在关闭对话框然后我们再次选择相同的项目后,它不会显示对话框,因为 onItemSelected
不会被调用。有什么解决方法吗?不使用自定义 Spinner
实现。
最佳答案
创建自定义微调器
import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Spinner;
public class CustomSpinner extends Spinner {
OnItemSelectedListener listener;
private AdapterView<?> lastParent;
private View lastView;
private long lastId;
public CustomSpinner(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
initlistner();
}
@Override
public void setSelection(int position) {
if (position == getSelectedItemPosition() && listener != null) {
listener.onItemSelected(lastParent, lastView, position, lastId);
} else {
super.setSelection(position);
}
}
private void initlistner() {
// TODO Auto-generated method stub
super.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
lastParent = parent;
lastView = view;
lastId = id;
if (listener != null) {
listener.onItemSelected(parent, view, position, id);
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
// TODO Auto-generated method stub
if (listener != null) {
listener.onNothingSelected(parent);
}
}
});
}
public void setOnItemSelectedEvenIfUnchangedListener(
OnItemSelectedListener listener) {
this.listener = listener;
}
}
设置监听器
private OnItemSelectedListener listener;
listener = new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
};
将监听器对象传递给自定义监听器
cusSpinner.setOnItemSelectedEvenIfUnchangedListener(listener);
关于安卓微调器 : onItemSelected listener is not called when selecting the same item,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/31742895/