在富文本框中搜索字符串

Question

这是我在我的 Richtextbox 中查找文本并突出显示它的代码：

        int start = 0;
        int indexOfSearchText = 0;

        private void button1_Click(object sender, EventArgs e)
        {
            int startindex = 0;

            if (textBox1.Text.Length > 0)
                startindex = FindMyText(textBox1.Text.Trim(), start, richTextBox1.Text.Length);

            // If string was found in the RichTextBox, highlight it
            if (startindex >= 0)
            {
                // Set the highlight color as red
                richTextBox1.SelectionBackColor = Color.Red;
                // Find the end index. End Index = number of characters in textbox
                int endindex = textBox1.Text.Length;
                // Highlight the search string
                richTextBox1.Select(startindex, endindex);
                richTextBox1.ScrollToCaret();
                // mark the start position after the position of
                // last search string
                start = startindex + endindex;
            }

            else
            {
                MessageBox.Show("0 occurence in richtextbox");
            }
        }

        public int FindMyText(string txtToSearch, int searchStart, int searchEnd)
        {
            // Unselect the previously searched string
            if (searchStart > 0 && searchEnd > 0 && indexOfSearchText >= 0)
            {
                richTextBox1.Undo();
            }

            // Set the return value to -1 by default.
            int retVal = -1;

            // A valid starting index should be specified.
            // if indexOfSearchText = -1, the end of search
            if (searchStart >= 0 && indexOfSearchText >= 0)
            {
                // A valid ending index
                if (searchEnd > searchStart || searchEnd == -1)
                {
                    // Find the position of search string in RichTextBox
                    indexOfSearchText = richTextBox1.Find(txtToSearch, searchStart, searchEnd, RichTextBoxFinds.None);
                    // Determine whether the text was found in richTextBox1.
                    if (indexOfSearchText != -1)
                    {
                        // Return the index to the specified search text.
                        retVal = indexOfSearchText;
                    }
                }
            }
            return retVal;
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            start = 0;
            indexOfSearchText = 0;
        }
    }
}

问题是，当它到达richtextBox1的末尾时，它并没有从头开始重新启动！我想在到达richtextBox1.text 的末尾后再次循环到开始。

Answer 1

这个怎么样？

if (textBox1.Text.Length > 0)
{
    startindex = FindMyText(textBox1.Text.Trim(), start, richTextBox1.Text.Length);
    if(startindex == -1 && start > 0) // Not found string and not searching from beginning
    {
        // Wrap search
        int oldStart = start;
        start = 0;
        startindex = FindMyText(textBox1.Text.Trim(), start, oldStart);
    }
}

Answer 2

下面的代码对于在richtextbox中搜索文本并以圆形方向突出显示文本很有用。我在richtextbox.i中使用文本框，我在文本框中输入搜索文本并按回车按钮查找下一个。最初我，m将 start 和 indexOfSearchText 的两个值声明为 0。

int 开始 = 0; int indexOfSearchText = 0;

private void textBox1_KeyDown(object sender, KeyEventArgs e)

     private void textBox1_KeyDown(object sender, KeyEventArgs e)   
        {
            if (e.KeyCode == Keys.Enter)


            {                   
                 int startindex = 0;

                if (textBox1.Text.Length > 0)
                {


                    startindex = FindMyText(textBox1.Text.Trim(), start, richTextBox1.Text.Length);

                    if (startindex == -1 && start >= 0) // Not found string and not searching from beginning
                    {
                        // Wrap search
                       // int oldStart = start;
                        start = 0;
                        startindex = FindMyText(textBox1.Text.Trim(), start, richTextBox1.Text.Length);
                    }


                }


                // If string was found in the RichTextBox, highlight it
                if (startindex >= 0)
                {
                    // Set the highlight color as red
                    richTextBox1.Select(startindex, textBox1.TextLength);
                    richTextBox1.SelectionBackColor = Color.Yellow;
                   // richTextBox1.SelectionColor = Color.Red;
                    // Find the end index. End Index = number of characters in textbox
                    int endindex = textBox1.Text.Length;
                    // Highlight the search string
                    richTextBox1.Select(startindex, endindex);
                    // mark the start position after the position of
                    // last search string
                    start = startindex + endindex;
                }

            }
        }



        public int FindMyText(string txtToSearch, int searchStart, int searchEnd)
        {
            // Unselect the previously searched string
            if (searchStart > 0 && searchEnd > 0 && indexOfSearchText >= 0)
            {
                richTextBox1.Undo();
            }

            // Set the return value to -1 by default.
            int retVal = -1;

            // A valid starting index should be specified.
            // if indexOfSearchText = -1, the end of search
            if (searchStart >= 0 && indexOfSearchText >= 0)
            {
                // A valid ending index
                if (searchEnd > searchStart || searchEnd == -1)
                {
                    // Find the position of search string in RichTextBox
                    indexOfSearchText = richTextBox1.Find(txtToSearch, searchStart, searchEnd, RichTextBoxFinds.None);
                    // Determine whether the text was found in richTextBox1.
                    if (indexOfSearchText != -1)
                    {
                        // Return the index to the specified search text.
                        retVal = indexOfSearchText;
                    }
                    else
                    {
                        start = 0;
                        indexOfSearchText = 0;
                        //return indexOfSearchText;
                    }
                }
            }
            return retVal;

        }

 private void textBox1_TextChanged(object sender, EventArgs e)
        {


            start = 0;
            indexOfSearchText = 0;
            string temp = richTextBox1.Text;
            richTextBox1.Text = string.Empty;
            richTextBox1.Text = temp;
            richTextBox1.SelectionBackColor = Color.White;
        }