c＃ - 在RichTextBox中插入表情符号会插入一些并忽略其他内容

Question

我有一个代码将richtextbox中的符号替换为表情符号，这是代码：

private void add_smileys(RichTextBox addin)
        {
            try
            {
                while (addin.Text.Contains(":)"))
                {
                    addin.SelectionStart = addin.Find(":)", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 2;

                    Image img = Resources.in_smile;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains(">:("))
                {
                    addin.SelectionStart = addin.Find(">:(", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 3;

                    Image img = Resources.in_angry;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains(":D"))
                {
                    addin.SelectionStart = addin.Find(":D", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 2;

                    Image img = Resources.in_lol;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains(":'("))
                {
                    addin.SelectionStart = addin.Find(":'(", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 3;

                    Image img = Resources.in_cry;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains(":("))
                {
                    addin.SelectionStart = addin.Find(":(", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 2;

                    Image img = Resources.in_sad;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains(";)"))
                {
                    addin.SelectionStart = addin.Find(";)", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 2;

                    Image img = Resources.in_wink;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains("xD"))
                {
                    addin.SelectionStart = addin.Find("xD", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 2;

                    Image img = Resources.in_laugh;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains(":P"))
                {
                    addin.SelectionStart = addin.Find(":P", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 2;

                    Image img = Resources.in_tongue;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains(":|"))
                {
                    addin.SelectionStart = addin.Find(":|", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 2;

                    Image img = Resources.in_neutral;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains("^^"))
                {
                    addin.SelectionStart = addin.Find("^^", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 2;

                    Image img = Resources.in_happy;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains("o.O"))
                {
                    addin.SelectionStart = addin.Find("o.O", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 3;

                    Image img = Resources.in_dizzy;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains(":S"))
                {
                    addin.SelectionStart = addin.Find(":S", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 2;

                    Image img = Resources.in_confused;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
                while (addin.Text.Contains(":O"))
                {
                    addin.SelectionStart = addin.Find(":O", RichTextBoxFinds.WholeWord);
                    addin.SelectionLength = 2;

                    Image img = Resources.in_omg;
                    Clipboard.SetImage(img);
                    addin.Paste();
                }
            }
            catch (Exception e)
            {
              MessageBox.Show(e.Message);
            }
        }

这是输出：

如你所见，有些符号被笑脸取代而有些符号则没有。而且，我得到了这个例外：

此错误的原因是什么？我该如何解决？

Answer 1

  

我收到此例外：在此处输入图片说明

  

此错误的原因是什么？以及如何修复它？

当Find方法查找的字符串不存在时，-1方法返回addin.SelectionStart。此值对Find无效。

在尝试使用该值之前，您应首先检查以确保-1的结果大于var selectionStart = addin.Find(":)", RichTextBoxFinds.WholeWord); if (selectionStart > -1) { addin.SelectionStart = selectionStart; addin.SelectionLength = 2; } 方法。

Find

您的包含和查找检查是多余的。出于某种原因，当你到达＆＃34; ^^＆＃34;他们返回不同的结果，这就是你得到错误的原因。但要删除冗余，您应该在循环中使用Contains方法而不是while (true) { var selectionStart = addin.Find(":)", RichTextBoxFinds.WholeWord); if (selectionStart > -1) { addin.SelectionStart = selectionStart; addin.SelectionLength = 2; } else { break; } } 。

Dictionary<string, Image>

我也认为你的方法不是很干净。您可以使用@以更简单，更易于维护的方式完成所有替换。您还应该使用private void add_smileys(RichTextBox addin) { var smileys = new Dictionary<string, Image>() { { @":)", Resources.in_smile }, { @">:(", Resources.in_angry }, { @":D", Resources.in_lol }, { @":'(", Resources.in_cry }, { @":(", Resources.in_sad }, { @";)", Resources.in_wink }, { @"xD", Resources.in_laugh }, { @":P", Resources.in_tongue }, { @":|", Resources.in_neutral }, { @"^^", Resources.in_happy }, { @"o.O", Resources.in_dizzy }, { @":S", Resources.in_confused }, { @":O", Resources.in_omg }, }; foreach (var smiley in smileys) { add_smiley(addin, smiley.Key, smiley.Value); } } private void add_smiley(RichTextBox addin, string token, Image smiley) { while (true) { var selectionStart = addin.Find(token, RichTextBoxFinds.WholeWord); if (selectionStart < 0) break; try { addin.SelectionStart = selectionStart; addin.SelectionLength = token.Length; Clipboard.SetImage(smiley); addin.Paste(); } catch (Exception ex) { MessageBox.Show(e.Message); break; } } } 符号来逃避字符串。

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