如何在Java中捕获材料下拉菜单选择的值？

huangapple
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英文:

How do I capture the value of a Material drop down menu selection in Java?

问题

我正在使用Material在Android Studio中使用Java设计一个带有下拉列表的表单。

我想要将用户从下拉列表中选择的内容保存到一个字符串中，以便我可以将其保存到Firebase，但是当我尝试记录结果时，它说选择为空。

有人知道我如何捕获用户从这种类型的下拉菜单中选择的内容吗？我之前有一个Spinner，它起作用，但是似乎不以相同的方式工作。

我的XML代码如下：

  1. <com.google.android.material.textfield.TextInputLayout
  2.     android:id="@+id/cpdTypeLayout"
  3.     style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox.ExposedDropdownMenu"
  4.     android:layout_width="match_parent"
  5.     android:layout_height="wrap_content"
  6.     android:layout_marginStart="16dp"
  7.     android:layout_marginEnd="16dp"
  8.     android:hint="Activity Type">
  10.     <AutoCompleteTextView
  11.         android:id="@+id/cpdType"
  12.         android:layout_width="match_parent"
  13.         android:layout_height="wrap_content"
  14.         android:inputType="none" />
  15. </com.google.android.material.textfield.TextInputLayout>

我的AddAdactivity.java代码如下：

  1. // CPD TYPE DROPDOWN MENU
  2. cpdTypeLayout = findViewById(R.id.cpdTypeLayout);
  3. cpdType = findViewById(R.id.cpdType);
  5. String[] type = new String[]{
  6.     "Formal Education Completed", "Other Completed", "Professional Activities", "Self-Directed Learning", "Work-Based Learning"
  7. };
  9. ArrayAdapter<String> adapterType = new ArrayAdapter<>(
  10.     AddActivity.this,
  11.     R.layout.dropdown_item,
  12.     type
  13. );
  15. cpdType.setAdapter(adapterType);
  17. cpdType.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
  18.     @Override
  19.     public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
  20.         selectedTypeResult = parent.getItemAtPosition(position).toString();
  21.     }
  23.     @Override
  24.     public void onNothingSelected(AdapterView<?> parent) {
  26.     }
  27. });
  29. Log.d("TAG", "You have selected " + selectedTypeResult);

编辑：之后尝试了以下方法，但没有成功。

  1. ((AutoCompleteTextView) cpdTypeLayout.getEditText()).setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
  2.     @Override
  3.     public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
  4.         adapterType.getItem(position);
  5.         String typeItem = ((AutoCompleteTextView) cpdTypeLayout.getEditText()).getText().toString();
  6.         Log.d("TAG", "selected type is:" + typeItem);
  7.     }
  9.     @Override
  10.     public void onNothingSelected(AdapterView<?> parent) {
  12.     }
  13. });

请注意，这些代码块是用于处理下拉列表选择的，您可以根据需要进行调整。

英文:

I am using Material to design a form with drop down lists in android studio using Java.

I want to save the selection the user makes from the drop down list to a string so I can save this to Firebase, but when I try and log the result, it says the selection is null.

Does anyone know how I can capture what the user selects from this type of drop down menu? I did previously have a Spinner which worked but this doesn't seem to work in the same manner.

My XML code is as follows

  1.  &lt;com.google.android.material.textfield.TextInputLayout
  2.             android:id=&quot;@+id/cpdTypeLayout&quot;
  3.             style=&quot;@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox.ExposedDropdownMenu&quot;
  4.             android:layout_width=&quot;match_parent&quot;
  5.             android:layout_height=&quot;wrap_content&quot;
  6.             android:layout_marginStart=&quot;16dp&quot;
  7.             android:layout_marginEnd=&quot;16dp&quot;
  8.             android:hint=&quot;Activity Type&quot;&gt;
  10.             &lt;AutoCompleteTextView
  11.                 android:id=&quot;@+id/cpdType&quot;
  12.                 android:layout_width=&quot;match_parent&quot;
  13.                 android:layout_height=&quot;wrap_content&quot;
  14.                 android:inputType=&quot;none&quot; /&gt;
  15.         &lt;/com.google.android.material.textfield.TextInputLayout&gt;

My AddAdactivity.java code is

  1. //CPD TYPE DROPDOWN MENU
  2.     cpdTypeLayout = findViewById(R.id.cpdTypeLayout);
  3.     cpdType = findViewById(R.id.cpdType);
  5.     String[] type = new String[]{
  6.             &quot;Formal Education Completed&quot;, &quot;Other Completed&quot;, &quot;Professional Activities&quot;, &quot;Self-Directed Learning&quot;, &quot;Work-Based Learning&quot;
  7.     };
  9.     ArrayAdapter&lt;String&gt; adapterType = new ArrayAdapter&lt;&gt;(
  10.             AddActivity.this,
  11.             R.layout.dropdown_item,
  12.             type
  13.     );
  15.     cpdType.setAdapter(adapterType);
  17.     cpdType.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
  18.         @Override
  19.         public void onItemSelected(AdapterView&lt;?&gt; parent, View view, int position, long id) {
  20.             selectedTypeResult = parent.getItemAtPosition(position).toString();
  21.         }
  23.         @Override
  24.         public void onNothingSelected(AdapterView&lt;?&gt; parent) {
  26.         }
  27.     });
  29.     Log.d(&quot;TAG&quot;, &quot;You have selected &quot; + selectedTypeResult);

EDIT: have since tried this but with no luck.

  1. ((AutoCompleteTextView)cpdTypeLayout.getEditText()).setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
  2.         @Override
  3.         public void onItemSelected(AdapterView&lt;?&gt; parent, View view, int position, long id) {
  4.             adapterType.getItem(position);
  5.             String typeItem = ((AutoCompleteTextView)cpdTypeLayout.getEditText()).getText().toString();
  6.             Log.d(&quot;TAG&quot;, &quot;selected type is:&quot; + typeItem);
  8.         }
  10.         @Override
  11.         public void onNothingSelected(AdapterView&lt;?&gt; parent) {
  13.         }
  14.     });

答案1

得分: 16

获取String只需使用以下代码：

  1. String selectedValue = ((AutoCompleteTextView) textInputLayout.getEditText()).getText();

如果你想使用监听器，可以使用类似以下代码：

  1. ((AutoCompleteTextView) textInputLayout.getEditText()).setOnItemClickListener(new AdapterView.OnItemClickListener() {
  2.     @Override
  3.     public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
  4.         String selectedValue = arrayAdapter.getItem(position);
  5.     }
  6. });
英文:

To get the String you can just use:

  1. String selectedValue =((AutoCompleteTextView)textInputLayout.getEditText()).getText();

Otherwise if you want to use a listener you can use something like:

  1.     ((AutoCompleteTextView)textInputLayout.getEditText()).setOnItemClickListener(new AdapterView.OnItemClickListener() {
  2.         @Override
  3.         public void onItemClick(AdapterView&lt;?&gt; adapterView, View view, int position, long id) {
  4.             String selectedValue = arrayAdapter.getItem(position);
  5.         }
  6.     });

huangapple
  • 本文由 发表于 2020年7月23日 00:52:00
  • 转载请务必保留本文链接：https://go.coder-hub.com/63039340.html
  • android
  • android-spinner
  • android-textinputlayout
  • java
  • material-components-android
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