c# - TextBox 行上的按钮 "clear"仅出现一次

Question

我设法用很少的代码在 TextBox 行上获得了一个清除按钮。这会在单击时删除相应的行及其本身。但是按钮只出现一次。它应该在每次单击每个附加行时生成。有人可以帮我吗？非常感谢。

是WinForm VS2010 C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Daten_zu_TextBox_Test
{
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        Button btn1 = new Button();
        btn1.Name = "btn";
        btn1.Click += new EventHandler(btn1_Click);
        btn1.Size = new Size(18, 18);
        btn1.Text = "X";
        btn1.ForeColor = Color.Red;
        textBox1.Controls.Add(btn1);

        string sent = ("\t" + "Testline1");

        textBox1.AppendText(sent);
        textBox1.AppendText(Environment.NewLine);
    }

    void btn1_Click(object sender, EventArgs e)
    {
        textBox1.Controls.Clear();
        textBox1.Text = textBox1.Text.Remove(1, textBox1.Lines[0].Length + 0 );
        textBox1.Text = textBox1.Text.Remove(0, textBox1.Lines[0].Length + 0);
    }

  }
}

private int ButtonCount2 = 0;
private int Btn2Y = 18;
private void button2_Click(object sender, EventArgs e)
{
    Button btn2 = new Button();
    btn2.Name = "btn2" + ButtonCount2;
    btn2.Click += new EventHandler(btn2_Click);
    btn2.Size = new Size(18, 18);
    btn2.Location = new Point(1, Btn2Y * ButtonCount2);

    ButtonCount2++;

    btn2.Text = "X";
    btn2.ForeColor = Color.Red;
    textBox2.Controls.Add(btn2);

    string sent = ("\t" + "Testline" + ButtonCount2);

    textBox2.AppendText(sent);
    textBox2.AppendText(Environment.NewLine);
}
void btn2_Click(object sender, EventArgs e)
{
    var bt2 = sender as Button;
    var bt2Id = textBox2.Controls.IndexOf(bt2);
    textBox2.Controls.Remove(bt2);
    var lines = textBox2.Text.Replace("\r\n", "\n").Split('\n').ToList();
    lines.RemoveAt(bt2Id);
    textBox2.Text = string.Join("\r\n", lines);

    foreach (Button btn2 in textBox2.Controls)
    {
        var Id2 = int.Parse(btn2.Name.Replace("btn2", ""));

        if (Id2 > bt2Id)
        {
            var b2 = textBox2.Controls.Find(btn2.Name, false)[0];
            var loc2 = btn2.Location;
            b2.Location = new Point(loc2.X, loc2.Y - Btn2Y);
         }
    }
    ButtonCount2--;
}

第二个按钮看起来像这样。

Answer 1

您将所有 X 按钮放在同一位置，在 textbox 之上。实现一些增加按钮 Y 位置的逻辑。可以是这样的:

//... your code here ...
btn1.ForeColor = Color.Red;
//increase Y
// for each control that is inside of textBox, 
// lower your newly created button by count * 18 
// so that btn1.Top will be 0, 18, 36 etc...
btn1.Top = textBox1.Controls.Count * 18; 
textBox1.Controls.Add(btn1); 

另外，正如 WPFUser 所注意到的，在单击 X 按钮时，您将删除所有 X 按钮。我猜你应该删除最后一个，最下面的一个

编辑 2. 每个按钮应该删除其对应的行，像这样(没有测试它:))

void btn1_Click(object sender, EventArgs e)
{
    //remove right line
    text1.Text = text1.Lines[text1.Controls.IndexOf((Control)sender)].Remove(0);
    //remove button
    text1.Controls.Remove(text1.Controls.OfType<Button>().Last());
}