从 C# 中的 Richtextbox 中选择文本 [英] Select text from a Richtextbox in C#

问题描述

我想选择富文本框文本最后一个{"和}"之间的文本.我有下一个代码，但我在LastIndexOf"函数上有错误，我不知道如何修复它.有人可以帮我吗?

I want to select the text that is between the last '{' and '}' of a richtextbox text. I have the next code, but I have an error on the "LastIndexOf" function and I don't know how to fix it. Can someone give me some help?

    private void highlightText()
    {
        mRtbxOperations.SelectionStart = mRtbxOperations.Text.LastIndexOf(@"{", 1, mRtbxOperations.SelectionStart);
        mRtbxOperations.SelectionLength = mRtbxOperations.Text.IndexOf(@"}", mRtbxOperations.SelectionStart, mRtbxOperations.Text.Length - 1);
        mRtbxOperations.SelectionBackColor = Color.LightBlue;
        mRtbxOperations.SelectionFont = new Font(mRtbxOperations.SelectionFont, FontStyle.Underline);
        mRtbxOperations.SelectionLength = 0;
    }

LastIndexOf 错误:

LastIndexOf Error:

计数必须为正，并且必须引用字符串、数组或集合.参数名称:计数

The count must be positive and must refer to a location within the string, array or collection. Parameter name: count

推荐答案

你的LastIndexOf参数搞乱了，还有选择的Length，需要减去起点才能得到合适的长度.

You LastIndexOf parameters are messed up, as well as the Length of the selection, where you need to substract the starting point in order to get the proper length.

尝试更简单的版本:

int textStart = mRtbxOperations.Text.LastIndexOf(@"{",
                                                 mRtbxOperations.SelectionStart);
if (textStart > -1) {
  int textEnd = mRtbxOperations.Text.IndexOf(@"}", textStart);
  if (textEnd > -1) {
    mRtbxOperations.Select(textStart, textEnd - textStart + 1);
    mRtbxOperations.SelectionBackColor = Color.LightBlue;
  }
}

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