using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace textbox
{
/// <summary>
/// MainWindow.xaml 的交互逻辑
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
textarea.TextChanged += textarea_TextChanged;
textarea.MaxWidth = 157;
}
private void textarea_TextChanged(object sender, TextChangedEventArgs e)
{
//textarea.TextChanged -= textarea_TextChanged;
int pos = textarea.SelectionStart;
string text = textarea.Text;
string modifyTxt = getTextWithNewLine(text);
if(text.Length != modifyTxt.Length)
{
int pos_x = lenb(modifyTxt) - lenb(text);
textarea.Text = modifyTxt;
if(pos%20 == pos/20)
{
int val = pos + pos_x;
if(val < 0)
{
val = 0;
}
textarea.SelectionStart = val;
}
else
{
textarea.SelectionStart = pos;
}
}
//Console.WriteLine(modifyTxt);
//textarea.TextChanged += textarea_TextChanged;
}
int lenb(string c)
{
int lens = Encoding.GetEncoding("Shift_Jis").GetByteCount(c);
return lens;
}
string getTextWithNewLine(string text)
{
char[] array = text.ToCharArray();
StringBuilder sb = new StringBuilder();
bool autoNewLine = true;
int index = 0;
int rowcont = 0;
for(int i=0;i<array.Length;i++)
{
char c = array[i];
if(c == '\r')
{
autoNewLine = false;
continue;
}
else if (c == '\n')
{
if (autoNewLine)
{
if(index < 19)
{
continue;
}
}else
{
sb.Append("\r\n");
index = 0;
rowcont++;
autoNewLine = true;
}
}
else
{
if (index > 19)
{
sb.Append('\n');
index = 0;
rowcont++;
}
sb.Append(c);
index += lenb(c + "");
}
}
return sb.ToString();
}
}
}
<TextBox x:Name="textarea" AcceptsReturn="True" Width="157" Height="200" VerticalScrollBarVisibility="Visible" BorderThickness="1">12345678901234567890</TextBox>
