根据另一个下拉菜单 Android 更改第二个下拉列表中的值

Question

我在Android中有2个下拉菜单。我想根据在第一个下拉列表中选择的值更改第二个下拉列表的内容。这是代码。

<string-array name="categoriesSpinner">
<item>ACCESS</item>
<item>AVAILABILITY - PERFORMANCE</item>
<item>FUNCTIONALITY</item>
<item>INQUIRY</item>
<item>DATA ERROR</item>
<item>ERROR MESSAGE</item>
</string-array>  

UI

<android.support.v7.widget.AppCompatSpinner
android:id="@+id/categorySpinner"
android:layout_width="match_parent"
android:layout_height="45sp"
android:hint="Category"
android:layout_marginTop="@dimen/margin_small"
android:background="@drawable/bg_drawable" />
<android.support.v7.widget.AppCompatSpinner
android:id="@+id/subcategorySpinner"
android:layout_width="match_parent"
android:layout_height="45sp"
android:hint="Sub-category"
android:layout_marginTop="@dimen/margin_small"
android:background="@drawable/bg_drawable" />  

Java:

public AppCompatSpinner mTextView, getmTextView;  
//AppCompatSpinner
mTextView = findViewById(R.id.categorySpinner);
String[] categories = getResources().getStringArray(R.array.categoriesSpinner);
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(mContext, R.layout.support_simple_spinner_dropdown_item, categories);
arrayAdapter.notifyDataSetChanged();
mTextView.setAdapter(arrayAdapter);
String option = String.valueOf(mTextView.getSelectedItem());
getmTextView = findViewById(R.id.subcategorySpinner);
if (option.contentEquals("ACCESS")) {
List<String> list = new ArrayList<>();
list.add("ACCOUNT LOCKED");
list.add("RESET PASSWORD");
ArrayAdapter<String> arrayAdapter1 = new ArrayAdapter<>(mContext, R.layout.support_simple_spinner_dropdown_item, list);
arrayAdapter1.notifyDataSetChanged();
getmTextView.setAdapter(arrayAdapter1);
}
if (option.contentEquals("AVAILABILITY - PERFORMANCE")) {
List<String> list = new ArrayList<>();
list.add("LIMITED - DEGRADED");
list.add("UNAVILABLE - DOWN");
ArrayAdapter<String> stringArrayAdapter = new ArrayAdapter<>(mContext, R.layout.support_simple_spinner_dropdown_item, list);
stringArrayAdapter.notifyDataSetChanged();
getmTextView.setAdapter(stringArrayAdapter);
}  

当我在我的 android 设备中运行代码时，单击第一个下拉列表中的第二个值时，第二个下拉列表的值不会改变。我该如何解决它？

Answer 1

将此代码移动到微调器的onItemSelected。

mTextView.setOnItemSelectedListener(//the remaining code
String option = String.valueOf(mTextView.getSelectedItem());  //Don't forget to move this here otherwise it won't be updated.
if (option.contentEquals("ACCESS")) {
List<String> list = new ArrayList<>();
list.add("ACCOUNT LOCKED");
list.add("RESET PASSWORD");
ArrayAdapter<String> arrayAdapter1 = new ArrayAdapter<>(mContext, R.layout.support_simple_spinner_dropdown_item, list);
arrayAdapter1.notifyDataSetChanged();
getmTextView.setAdapter(arrayAdapter1);
}
if (option.contentEquals("AVAILABILITY - PERFORMANCE")) {
List<String> list = new ArrayList<>();
list.add("LIMITED - DEGRADED");
list.add("UNAVILABLE - DOWN");
ArrayAdapter<String> stringArrayAdapter = new ArrayAdapter<>(mContext, R.layout.support_simple_spinner_dropdown_item, list);
stringArrayAdapter.notifyDataSetChanged();
getmTextView.setAdapter(stringArrayAdapter);
);