Winform procedure, have a little more, feel ifelse nested how ifelse nested by the state pattern, please advise, thank you,

 private void UploadBtn_Click (object sender, EventArgs e) {
If (string. IsNullOrWhiteSpace (ScanTbx. Text)) return; 
A string of text=ScanTbx. Text. The Trim (); 
Using (var connection=SqlCon TestDbConnection ()) {
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
if (! Next) {
If (LuhnAlgorithm IsValidNumber (text)) {
String imei=$" select * from Binding where imei='{text} "; 
Var imeiQuery=connection. Query (imei). ToList (); 
If ((imeiQuery. Count==0) | | cbxEdit865Code. Checked) {
LblIMEI. Text=Text; 
Next=! Next; 
Label1. Text="please scan small barcode"; 
} 
The else {
MessageBox. Show (" IMEI scanned ", "warning", MessageBoxButtons. OK, MessageBoxIcon. Error, MessageBoxDefaultButton. For the); 
} 
} 
The else {
IMEI MessageBox. Show (" Error ", "warning", MessageBoxButtons. OK, MessageBoxIcon. Error, MessageBoxDefaultButton. For the); 
} 
} 
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
The else {
If (cbxEditCode. Checked) {
String editSN=$" update Binding set SN='{text} where IMEI=' {lblIMEI. Text} "; 
Var sqlUpdateSN=connection. The Execute (editSN); 
If (sqlUpdateSN & gt; 0 {
Next=! Next; 
Label1. Text="please scan barcode I"; 
LblIMEI. Text=""; 
CbxEdit865Code. Checked=false; 
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
String query="select * from the Binding order by BindingDate desc"; 
Var this=connection. Query (query). ToList (); 
DataGridView1. The DataSource=this; 
} 
The else {
MessageBox. Show (" modify "failure," tip ", MessageBoxButtons. OK, 
MessageBoxIcon Error, MessageBoxDefaultButton. For); 
} 
} 
The else {
String of sn=$" select * from Binding where sn='{text} "; 
Var snQuery=connection. Query (sn). ToList (); 
If (snQuery. Count==0) {
String insert=$" insert into Binding (IMEI, SN) values (" + 
$" '{lblIMEI. Text}', '{Text}) "; 
Var sqlInsert=connection. The Execute (insert); 
If (sqlInsert & gt; 0 {
Next=! Next; 
Label1. Text="please scan barcode"; 
LblIMEI. Text=""; 
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
String query="select * from the Binding order by BindingDate desc"; 
Var this=connection. Query (query). ToList (); 
DataGridView1. The DataSource=this; 
} 
The else {
MessageBox. Show (" binding "failure," tip ", MessageBoxButtons. OK, 
MessageBoxIcon Error, MessageBoxDefaultButton. For); 
} 
} 
The else {
MessageBox. Show (" little barcode scanned ", "prompt", MessageBoxButtons. OK, 
MessageBoxIcon Error, MessageBoxDefaultButton. For); 
} 
} 
} 
} 
ScanTbx. The Clear (); 
ScanTbx. Focus (); 
return; 
}