Question

我有一个包含类别列表的Spinner，它从JSON获取数据。我想，当选择 All Category 以外的项目时，另一个子类别的微调器变得可见，并根据其类别从JSON加载数据。

之前我设法做到了，但是在离开它几天并完成其他部分之后，它就不再有用了。

由于第一个加载到微调器中的是所有类别，因此它触发了setOnItemSelectedListener()并隐藏了subcategorySpinner。如果其他项目被选中，则subcategorySpinner仍未显示。

代码逻辑有问题吗？请帮忙。

categorySpinner = (Spinner) rootView.findViewById(R.id.categorySpinner);
ArrayAdapter<String> adapter2 = new ArrayAdapter<String>(getActivity().getApplicationContext(), R.layout.spinner_item, categoryList);
adapter2.setDropDownViewResource(R.layout.spinner_dropdown_item);
categorySpinner.setAdapter(adapter2);

categorySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
categoryString = categorySpinner.getSelectedItem().toString().replace(" ", "%20");
if (categorySpinner.getSelectedItem().toString().equals("All Category")) {
   Log.d("debug", "all category");
   subcategorySpinner.setVisibility(View.GONE);
} else {
   Log.d("debug", "other than all category");
   subcategorySpinner.setVisibility(View.VISIBLE);
   generateSubcategorySpinner(Config.GET_SUBCATEGORY_URL+"?category="+categoryString);
}
}


});

Answer 1

将您的代码更改为

categorySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {


// On selecting a spinner item
categoryString = parent.getItemAtPosition(position).toString();
Log.d("debug", categoryString+"..."+position);

if (categoryString.equals("All Category")) {
   Log.d("debug", "all category");
   subcategorySpinner.setVisibility(View.GONE);
} else {
   Log.d("debug", "other than all category");
   subcategorySpinner.setVisibility(View.VISIBLE);

   categoryString = categoryString.replace(" ", "%20")
   generateSubcategorySpinner(Config.GET_SUBCATEGORY_URL+"?category="+categoryString);
}
}

Answer 2

试试此代码段

Spinner dropdown = (Spinner) findViewById(R.id.type);
final String[] items = new String[]{"SELECT TYPE OF OFFER","PERCENTAGE", "AMOUNT", "ITEM"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,R.layout.spinner_item, items);
dropdown.setAdapter(adapter);
String selectedItem = dropdown.getSelectedItem().toString();

Answer 3

试试这个

categorySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {


// On selecting a spinner item
         categoryString = parent.getItemAtPosition(position).toString().replace(" ", "%20");



if (categoryString.equals("All Category")) {
   Log.d("debug", "all category");
   subcategorySpinner.setVisibility(View.GONE);
} else {
   Log.d("debug", "other than all category");
   subcategorySpinner.setVisibility(View.VISIBLE);
   generateSubcategorySpinner(Config.GET_SUBCATEGORY_URL+"?category="+categoryString);
}
}

Answer 4

你可以直接使用，参数（位置）

而不是， categoryString = parent.getItemAtPosition（position）.toString（）;

你可以使用， categoryString = position.toString（）;

Answer 5

嗯，我不能完全理解我在逻辑上所做的事情，因为它看起来没什么不同但是这解决了它。哦，好吧......不管怎么说，无论是漂浮在船上，我猜。

使用H Raval的建议，我将if else移动到一个方法中，现在它就像我想要的那样工作。

categorySpinner = (Spinner) rootView.findViewById(R.id.categorySpinner);
                ArrayAdapter<String> adapter2 = new ArrayAdapter<String>(getActivity().getApplicationContext(), R.layout.spinner_item, categoryList);
                adapter2.setDropDownViewResource(R.layout.spinner_dropdown_item);
                categorySpinner.setAdapter(adapter2);
                String str = categorySpinner.getSelectedItem().toString();
                Log.d("debug", "str "+str);

                categorySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                    @Override
                    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                        categoryString = parent.getItemAtPosition(position).toString();
                        Log.d("debug", categoryString+"..."+position);

                        subCategorySpinnerView(categoryString);
                    }
                });

private void subCategorySpinnerView(String categoryString) {

    if (categoryString.equals("All Category")) {
        Log.d("debug", "all category");
        subcategorySpinner.setVisibility(View.GONE);
    } else {
        Log.d("debug", "other than all category");
        subcategorySpinner.setVisibility(View.VISIBLE);

        categoryString = categoryString.replace(" ", "%20");
        generateSubcategorySpinner(Config.GET_SUBCATEGORY_URL+"?category="+categoryString);
    }

}

没有来自getSelectedItem Spinner的响应

5 个答案: