在将数据插入表格之前，如何限制数据的字符数？

Question

I want to restrict the number of character before inserting it to the table. For example, I retrieved the value of the column "Address" whose data length is of 44 characters. But when I need to insert this value to another table, I want to restrict only 40 characters in the column "Address2" of another table as its data type is of 40 in length. Please help

Answer 1

Try this:

If (sAddress != null && sAddress.Length > 40) {
    sAddress = sAddress.SubString(0, 40)
}

Answer 2

Put some validation on text box which is present on your form/page to accept only 40 characters . You can use following regular expression which will validate the input text for max 40 characters -

^.{1,40}$

Answer 3

You can check the strings length simply and make some action if it is greater that the allowed length.

For example, You can truncate the string with a function like this:

string truncate(string s, int length)
{        
 return ( s.Length > length ) ?  s.Substring(0, length) : s;
}

so truncate(Address,40) will give You a shorter string and You can use it every time with this short form with any length.

Answer 4

string YourVar = YourTextBox.text;
string VarToInsert = YourVar.Substring(0,40);

Answer 5

For MVVM in WPF you can use DataAnnotations

    [Range(1,40)]
    public string Name
    {
        get { return _name; }
        set
        {
            _name = value;
            RaisePropertyChanged("Name"));
        }
    }

XAML

<TextBox  Text="{Binding Name, ValidatesOnDataErrors=True}">