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
Spinner spnLocale = (Spinner)findViewById(R.id.spnLocale);
spnLocale.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
// Your code here
}
public void onNothingSelected(AdapterView<?> adapterView) {
return;
}
});
注意:记住一件事。
OnItemSelectedListener事件将执行两次:
旋转器初始化 手动选择的用户
试着用标志变量来区分这两者。
其他回答
Spinner spnLocale = (Spinner)findViewById(R.id.spnLocale);
spnLocale.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
// Your code here
}
public void onNothingSelected(AdapterView<?> adapterView) {
return;
}
});
注意:记住一件事。
OnItemSelectedListener事件将执行两次:
旋转器初始化 手动选择的用户
试着用标志变量来区分这两者。
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。
spinner1.setOnItemSelectedListener(
new AdapterView.OnItemSelectedListener() {
//add some code here
}
);
您可以实现AdapterView。Activity中的OnItemSelectedListener类。
然后在onCreate()中使用下面的行
Spinner spin = (Spinner) findViewById(R.id.spinner);
spin.setOnItemSelectedListener(this);
然后重写这两个方法:
public void onItemSelected(AdapterView<?> parent, View v, int position, long id) {
selection.setText(items[position]);
}
public void onNothingSelected(AdapterView<?> parent) {
selection.setText("");
}
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