我正在使用ASP.NET。我有一个动态构建的Dropdownlist。现在，当您点击提交按钮时，我只会在您从下拉列表中选择某些内容时尝试执行某些操作（如果值不是0＆＃39;则为＆＃39;）。但不知何故，我的值总是返回0（默认值），当选择了某些内容并且值应为1或2时。
这里有谁知道可能出现什么问题？
在这里，我循环遍历我的所有下拉列表，每个下拉列表都有一个电子邮件输入（这两个属于一起）
For i As Integer = 0 To allDropDownLists.Count - 1
If allDropDownLists(i).SelectedValue = "0" Then
Else
If allEmailInputs(i).Text IsNot "" Then
final &= saveEventUser(myID, allDropDownLists(i).SelectedValue, allEmailInputs(i).Text)
Else
error.InnerHtml = "error!!"
End If
End If
Next
这就是动态构建所有内容的方式：
Dim div71 As New Panel
div71.CssClass = "border"
Dim ddl As New DropDownList
ddl.ID = "select" & panel & "_" & counter
ddl.Items.Clear()
ddl.Items.Add(New ListItem("Select something", "0"))
ddl.Items.Add(New ListItem("Select 1", "1"))
ddl.Items.Add(New ListItem("Select 2", "2"))
ddl.CssClass = "form_txt2 colegas"
答案 0 :(得分：0)
使用visibile =＆＃34; false＆＃34;以标准ASP.NET方式创建下拉列表，然后填充时将其可见性设置为true。
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="BatchID" OnSelectedIndexChanged="GridView1_SelectedIndexChanged">
<Columns>
<asp:BoundField DataField="Column1" HeaderText="Column1" SortExpression="Column1" />
<asp:BoundField DataField="Column2" HeaderText="Column2" SortExpression="Column2" />
<asp:TemplateField>
<ItemTemplate>
<asp:DropDownList ID="DropDownList1" runat="server">
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
否则，您可以构建一个GridView，其中每行都有一个DropDownList，因此您可以控制要显示的行数（因此 - > DropDownLists） - 如果将此GridView绑定到具有5条记录的数据集，您将有5个DropDownLists。
public class OptionMenuFragment extends Fragment implements View.OnClickListener{
private String phoneNumber, email;
public OptionMenuFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.option_main_fragment, container, false);
Button myColleagues=(Button) view.findViewById(R.id.myColleagues);
myColleagues.setOnClickListener(this);
......
return view;
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.myColleagues:
Intent intent = new Intent(getActivity(), MyColleaguesPage.class);
startActivity(intent);
break;
case R.id.news:
......
break;
}
}
private void showFirstDialog() {
//Create a new builder and get the layout.
final AlertDialog.Builder builder = new AlertDialog.Builder(this.getActivity());
......
alertButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
alert.dismiss();
}
});
alertListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// ListView Clicked item index
int itemPosition = position;
if (itemPosition == 0) {
alert.dismiss();
showSecondDialog(0);
}
.......
else if (itemPosition == 5) {
alert.dismiss();
showSecondDialog(5);
}
}
});
}
private void showSecondDialog(int position) {
alertTitle.setText("What do you want to do");
// Defined Array values to show in ListView
String[] values = getResources().getStringArray(R.array.contact_way);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this.getActivity(),
R.layout.first_alertlist_textstyle, android.R.id.text1, values);
alertListView.setAdapter(adapter);
alertButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
alert.dismiss();
}
});
switch (position) {
case 0:
phoneNumber = "123456";
email="mail.com";
break;
......
case 5:
phoneNumber = "+1233";
email="mail.com";
}
alertListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// ListView Clicked item index
int itemPosition = position;
if (itemPosition == 0) {
alert.dismiss();
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("calling to " + phoneNumber);
//builder.setMessage("Are you sure you want to log out?");
builder.setPositiveButton("Call", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// close the dialog, go to login page
if (isPermissionGranted()) {
call_action(); //here I am calling call method
}
}
});
builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// Do nothing
dialog.dismiss();
}
});
AlertDialog alert = builder.create();
alert.show();
}
if (itemPosition == 1) {
..
}
if (itemPosition == 2) {
....
}
//This code I want to implement into seperate class
public void call_action(){
Intent callIntent = new Intent(Intent.ACTION_CALL);
callIntent.setData(Uri.parse("tel:" + phoneNumber));
startActivity(callIntent);
}
public boolean isPermissionGranted() {
if (Build.VERSION.SDK_INT >= 23) {
if (getActivity().checkSelfPermission(android.Manifest.permission.CALL_PHONE)
== PackageManager.PERMISSION_GRANTED) {
Log.v("TAG","Permission is granted");
return true;
} else {
Log.v("TAG","Permission is revoked");
ActivityCompat.requestPermissions(this.getActivity(), new String[]{Manifest.permission.CALL_PHONE}, 1);
return false;
}
}
else { //permission is automatically granted on sdk<23 upon installation
Log.v("TAG","Permission is granted");
return true;
}
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case 1: {
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(getActivity().getApplicationContext(), "Permission granted", Toast.LENGTH_SHORT).show();
call_action();
} else {
Toast.makeText(getActivity().getApplicationContext(), "Permission denied", Toast.LENGTH_SHORT).show();
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
您将在GridView RowDataBound事件上填充这些DropDownLists