C# 數字轉字串補0 & 字串補0

01.數字轉字串補0:

this.f1_textBox2.Text = String.Format("{0:0000000000000000}",(Convert.ToInt16(this.f1_textBox2.Text) + 1));

 

02.字串補0:

string str = "9";
str.PadLeft(4, '0');//-->0009
str.PadRight(4, '0');//-->9000