删除.NET RichTextBox中的特定行

Question

如何删除RichTextBox中的特定行文本？

Answer 1

我不知道是否有一个简单的方法来做到这一步。您可以使用.Split功能上的丰富文本框。文本属性来获取线

string[] lines = richTextBox1.Text.Split("\n".ToCharArray()) 

的数组，然后写的东西去掉，你行后，重新组装阵列成一个单一的文本字符串并将其复制回富文本框的.Text属性。

这里有一个简单的例子：如果您的富文本框将不得不超过10行左右，这将是使用StringBuilder而不是字符串来组成新的文本是一个好主意

 string[] lines = richTextBox1.Text.Split("\n".ToCharArray()); 


     int lineToDelete = 2;   //O-based line number 

     string richText = string.Empty; 

     for (int x = 0 ; x < lines.GetLength(0) ; x++) 
     { 
      if (x != lineToDelete) 
      { 
       richText += lines[ x ]; 
       richText += Environment.NewLine; 
      } 
     } 

     richTextBox1.Text = richText; 

用。

Answer 2

查找要在文本范围内删除的文本，找到here将文本设置为空，现在它从文档中消失。

Answer 3

另一种解决方案：

private void DeleteLine(int a_line) 
{ 
    int start_index = richTextBox.GetFirstCharIndexFromLine(a_line); 
    int count = richTextBox.Lines[a_line].Length; 

    // Eat new line chars 
    if (a_line < richTextBox.Lines.Length - 1) 
    { 
     count += richTextBox.GetFirstCharIndexFromLine(a_line + 1) - 
      ((start_index + count - 1) + 1); 
    } 

    richTextBox.Text = richTextBox.Text.Remove(start_index, count); 
} 

Answer 4

试试这个：基于tomanu的解决方案，但没有开销

int start_index = LogBox.GetFirstCharIndexFromLine(linescount); 
int count = LogBox.GetFirstCharIndexFromLine(linescount + 1) - start_index; 
LogBox.Text = LogBox.Text.Remove(start_index, count); 

注意m

Dim lst As New ListBox 
     Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click 
      Me.Controls.Add(lst) 
      For Each cosa As String In Me.RichTextBox1.Lines 
       lst.Items.Add(cosa) 
      Next 
      lst.Items.RemoveAt(2) 'the integer value must be the line that you want to remove -1 
      Me.RichTextBox1.Text = String.Empty 
      For i As Integer = 0 To lst.Items.Count - 1 
       If Me.RichTextBox1.Text = String.Empty Then 
        Me.RichTextBox1.Text = lst.Items.Item(i) 
       Else 
        MeMe.RichTextBox1.Text = Me.RichTextBox1.Text & Environment.NewLine & lst.Items.Item(i).ToString 
       End If 
      Next 
     End Sub 

http://social.msdn.microsoft.com/Forums/en-US/vbgeneral/thread/63647481-743d-4e55-9043-e0db5106a03a/

Answer 5

y linescount here is linescount - 2.

Answer 6

这也可以做到这一点（如果你可以在窗体代码中处理诸如++之类的东西）。保持文本格式。只记得您和用户的“只读”属性。

richTextBox.SelectionStart = richTextBox.GetFirstCharIndexFromLine(your_line); 
richTextBox.SelectionLength = this.richTextBox.Lines[your_line].Length+1; 
this.richTextBox.SelectedText = String.Empty; 

Answer 7

这是我的单元测试的实现。

public static void DeleteLine([NotNull] this RichTextBox pRichTextBox, int pLineIndex) { 
    if (pLineIndex < 0 || pLineIndex >= pRichTextBox.Lines.Length) 
     throw new InvalidOperationException("There is no such line."); 

    var start = pRichTextBox.GetFirstCharIndexFromLine(pLineIndex); 
    var isLastLine = pLineIndex == pRichTextBox.Lines.Length - 1; 
    var nextLineIndex = pLineIndex + 1; 

    var end = isLastLine 
     ? pRichTextBox.Text.Length - 1 
     : pRichTextBox.GetFirstCharIndexFromLine(nextLineIndex) - 1; 

    var length = end - start + 1; 
    pRichTextBox.Text = pRichTextBox.Text.Remove(start, length); 
} 

单元测试：

[TestMethod] 
public void TestDeleteLine_SingleLine() { 
    var rtb = new RichTextBox(); 
    rtb.Text = "This is line1.\n"; 
    rtb.DeleteLine(0); 
    var expected = ""; 
    Assert.AreEqual(expected, rtb.Text); 
} 

[TestMethod] 
public void TestDeleteLine_BlankLastLine() { 
    var rtb = new RichTextBox(); 
    rtb.Text = "\n"; 
    rtb.DeleteLine(1); 
    var expected = "\n"; 
    Assert.AreEqual(expected, rtb.Text); 
} 

[TestMethod] 
public void TestDeleteLine_SingleLineNoEOL() { 
    var rtb = new RichTextBox(); 
    rtb.Text = "This is line1."; 
    rtb.DeleteLine(0); 
    var expected = ""; 
    Assert.AreEqual(expected, rtb.Text); 
} 

[TestMethod] 
public void TestDeleteLine_FirstLine() { 
    var rtb = new RichTextBox(); 
    rtb.Text = "This is line1.\nThis is line2.\nThis is line3."; 
    rtb.DeleteLine(0); 
    var expected = "This is line2.\nThis is line3."; 
    Assert.AreEqual(expected, rtb.Text); 
} 

[TestMethod] 
public void TestDeleteLine_MiddleLine() { 
    var rtb = new RichTextBox(); 
    rtb.Text = "This is line1.\nThis is line2.\nThis is line3."; 
    rtb.DeleteLine(1); 
    var expected = "This is line1.\nThis is line3."; 
    Assert.AreEqual(expected, rtb.Text); 
} 

[TestMethod] 
public void TestDeleteLine_LastLine() { 
    var rtb = new RichTextBox(); 
    rtb.Text = "This is line1.\nThis is line2.\nThis is line3."; 
    rtb.DeleteLine(2); 
    var expected = "This is line1.\nThis is line2.\n"; 
    Assert.AreEqual(expected, rtb.Text); 
} 

[TestMethod] 
public void TestDeleteLine_OneBlankLine() { 
    var rtb = new RichTextBox(); 
    rtb.Text = "\n"; 
    rtb.DeleteLine(0); 
    var expected = ""; 
    Assert.AreEqual(expected, rtb.Text); 
} 

[TestMethod] 
public void TestDeleteLine_BlankLines() { 
    var rtb = new RichTextBox(); 
    rtb.Text = "\n\n\n\n\n"; 
    rtb.DeleteLine(2); 
    var expected = "\n\n\n\n"; 
    Assert.AreEqual(expected, rtb.Text); 
} 

[TestMethod, ExpectedException(typeof(InvalidOperationException))] 
public void TestDeleteLine_Exception_BeforeFront() { 
    var rtb = new RichTextBox(); 
    rtb.Text = "\n\n\n\n\n"; 
    rtb.DeleteLine(-1); 
} 

[TestMethod, ExpectedException(typeof(InvalidOperationException))] 
public void TestDeleteLine_Exception_AfterEnd() { 
    var rtb = new RichTextBox(); 
    rtb.Text = "\n\n"; 
    rtb.DeleteLine(3); 
} 

Answer 8

很多好的答案（因为至少使用\n代替Environment.NewLine我RTB自动与刚刚\n更换\r\n），但我发现很多很复杂。

string[] LinesArray = this.richTextBox1.Lines; 

this.richTextBox1.Clear(); 

for (int line = 0; line < LinesArray.Length; line++) 
{ 
if (!LinesArray[line].Contains("< Test Text To Remove >")) 
{ 
this.richTextBox1.AppendText(LinesArray[line] + Environment.NewLine); 
} 
} 

我希望这可以帮助别人一些; 0）