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
你在onCreate或onStart中设置OnItemSelectedListener并不重要——它仍然会在活动创建或启动期间被调用(分别)。 所以我们可以在onCreate中设置它(而不是在onStart中!) 只需添加一个标志来计算第一次初始化:
private Spinner mSpinner;
private boolean mSpinnerInitialized;
然后在onCreate(或onCreateView)中只需:
mSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
if (!mSpinnerInitialized) {
mSpinnerInitialized = true;
return;
}
// do stuff
}
public void onNothingSelected(AdapterView<?> adapterView) {
return;
}
});
其他回答
找到你的微调器名称和id,然后实现这个方法。
spinnername.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
// your code here
}
@Override
public void onNothingSelected(AdapterView<?> parentView) {
// your 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("");
}
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。
你在onCreate或onStart中设置OnItemSelectedListener并不重要——它仍然会在活动创建或启动期间被调用(分别)。 所以我们可以在onCreate中设置它(而不是在onStart中!) 只需添加一个标志来计算第一次初始化:
private Spinner mSpinner;
private boolean mSpinnerInitialized;
然后在onCreate(或onCreateView)中只需:
mSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
if (!mSpinnerInitialized) {
mSpinnerInitialized = true;
return;
}
// do stuff
}
public void onNothingSelected(AdapterView<?> adapterView) {
return;
}
});
这是可行的 初始化旋转器和findviewbyid并使用它将工作
Spinner schemeStatusSpinner;
schemeStatusSpinner = (Spinner) dialog.findViewById(R.id.spinner);
schemeStatusSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
// your code here
if(schemeStatusSpinner.getSelectedItemId()==4){
reasonll.setVisibility(View.VISIBLE);
}
else {
reasonll.setVisibility(View.GONE);
}
}
@Override
public void onNothingSelected(AdapterView<?> parentView) {
// your code here
}
});