当所选项目发生变化时,如何为微调器设置事件侦听器?
基本上我想做的是类似这样的事情:
spinner1.onSelectionChange = handleSelectionChange;
void handleSelectionChange(Object sender){
//handle event
}
当所选项目发生变化时,如何为微调器设置事件侦听器?
基本上我想做的是类似这样的事情:
spinner1.onSelectionChange = handleSelectionChange;
void handleSelectionChange(Object sender){
//handle event
}
当前回答
对于kotlin,您可以使用:
spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
}
override fun onNothingSelected(p0: AdapterView<*>?) {
}
}
注意:对于onItemSelected方法的参数,我使用自定义变量名
其他回答
我知道这个问题解决了很长时间,但我有一个“请选择”字符串在我的字符串数组的顶部。然后,当您编写侦听器时
yourspinner.onItemSelectedListener = object : OnItemSelectedListener {
override fun onItemSelected(adapterView: AdapterView<*>?, view: View, i: Int, l: Long) {
yourvalue = yourspinner.getSelectedItem().toString()
when(yourvalue){
"Please Select" -> // DO nothing
else -> // Do something
}
}
override fun onNothingSelected(adapterView: AdapterView<*>?) {
return
}
}
当然,您可以扩展when语句以拥有不同的响应或操作。
为当前旋转器的选择取一个全局变量:
int currentItem = 0;
spinner_counter = (Spinner)findViewById(R.id.spinner_counter);
String[] value={"20","40","60","80","100","All"};
aa=new ArrayAdapter<String>(this,R.layout.spinner_item_profile,value);
aa.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner_counter.setAdapter(aa);
spinner_counter.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
if(currentItem == position){
return; //do nothing
}
else
{
TextView spinner_item_text = (TextView) view;
//write your code here
}
currentItem = position;
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
//R.layout.spinner_item_profile
<?xml version="1.0" encoding="utf-8"?>
<TextView android:id="@+id/spinner_item_text"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/border_close_profile"
android:gravity="start"
android:textColor="@color/black"
android:paddingLeft="5dip"
android:paddingStart="5dip"
android:paddingTop="12dip"
android:paddingBottom="12dip"
/>
//drawable/border_close_profile
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape android:shape="rectangle">
<solid android:color="#e2e3d7" />
</shape>
</item>
<item android:left="1dp"
android:right="1dp"
android:top="1dp"
android:bottom="1dp">
<shape android:shape="rectangle">
<solid android:color="@color/white_text" />
</shape>
</item>
</layer-list>
spinner1.setOnItemSelectedListener(
new AdapterView.OnItemSelectedListener() {
//add some code here
}
);
对于kotlin,您可以使用:
spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
}
override fun onNothingSelected(p0: AdapterView<*>?) {
}
}
注意:对于onItemSelected方法的参数,我使用自定义变量名
spinner-widget的文档说
旋转器不支持项目单击事件。
您应该使用setOnItemSelectedListener来处理您的问题。