//1.
using System.Runtime.InteropServices;

?//2.
import kernel32.dll

[DllImport("kernel32.dll",EntryPoint = "LCMapStringA")]?
　　??? public static extern int LCMapString(int Locale,int dwMapFlags,byte[] lpSrcStr,int cchSrc,byte[] lpDestStr,int cchDest);?
　　??? const int LCMAP_SIMPLIFIED_CHINESE = 0x02000000;?
　　??? const int LCMAP_TRADITIONAL_CHINESE = 0x04000000;
?//3.轉簡體

private void btnCHS_Click(object sender, EventArgs e)?
??????? {?
??????????? string src = txtSrcText.Text.Trim();?
??????????? byte[] srcByte = Encoding.Default.GetBytes(src);?
??????????? byte[] desByte = new byte[srcByte.Length];?
??????????? LCMapString(2052, LCMAP_SIMPLIFIED_CHINESE, srcByte, -1, desByte, srcByte.Length);?
??????????? string des = Encoding.Default.GetString(desByte);?
??????????? txtDesText.Text = des;?
??????? }
?//4.轉繁體

private void btnCHT_Click(object sender, EventArgs e)?
??????? {?
??????????? string src = txtSrcText.Text.Trim();?
??????????? byte[] srcByte = Encoding.Default.GetBytes(src);?
??????????? byte[] desByte = new byte[srcByte.Length];?
?????????????
??????????? LCMapString(2052, LCMAP_TRADITIONAL_CHINESE, srcByte, -1, desByte, srcByte.Length);?
??????????? string des = Encoding.Default.GetString(desByte);?
??????????? txtDesText.Text = des;?
??????? }
===============第二種=====================
//1. 參考Microsoft.VisualBasic.dll

//2. 轉簡體代碼

private void btnCHS_Click(object sender, EventArgs e)?
??????? {?
??????????? string src = txtSrcText.Text.Trim();?
??????????? string des = Microsoft.VisualBasic.Strings.StrConv(src, Microsoft.VisualBasic.VbStrConv.SimplifiedChinese, 0);?
??????????? txtDesText.Text = des;?
??????? }
//3. 轉繁體代碼

private void btnCHT_Click(object sender, EventArgs e)?
??????? {?
??????????? string src = txtSrcText.Text.Trim();?
??????????? string des = Microsoft.VisualBasic.Strings.StrConv(src, Microsoft.VisualBasic.VbStrConv.TraditionalChinese, 0);?
??????????? txtDesText.Text = des;?
??????? }