c# 将 .docx 文件加载到 richtextbox 中花费的时间太长

Question

我打算将 word 文档加载到 richtextbox 中。

我有以下代码。是的，它正在工作，但它需要很长时间才能加载。

OpenFileDialog ofd = new OpenFileDialog();
ofd.Filter = "Word Documents|*.doc; *.docx";

if (ofd.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
    Microsoft.Office.Interop.Word.Application word = new Microsoft.Office.Interop.Word.Application();
    object miss = System.Reflection.Missing.Value;
    object path = ofd.FileName;
    object readOnly = true;
    Microsoft.Office.Interop.Word.Document docs = word.Documents.Open(ref path, ref miss, ref readOnly,
        ref miss, ref miss, ref miss, ref miss, ref miss, ref miss, ref miss, ref miss, ref miss,
        ref miss, ref miss, ref miss, ref miss);
    string totaltext = "";


    for (int i = 0; i < docs.Paragraphs.Count; i++)
    {
        totaltext += "\t " + docs.Paragraphs[i + 1].Range.Text.ToString();
    }

    richTextBox1.Text = totaltext;
}

加载一个 3 页的测试文档大约需要 2 分钟，而加载一个 60 多页的文档则需要大约 2 分钟。

可能与for循环有关。请帮助我提高速度。

Answer 1

代替

string totaltext = "";

for (int i = 0; i < docs.Paragraphs.Count; i++)
{
    totaltext += "\t " + docs.Paragraphs[i + 1].Range.Text.ToString();
}

richTextBox1.Text = totaltext;

使用这个:

var totaltextBuilder = new StringBuilder();

for (int i = 0; i < docs.Paragraphs.Count; i++)
{
    totaltextBuilder.Append("\t " + docs.Paragraphs[i + 1].Range.Text.ToString());
}

richTextBox1.Text = totaltextBuilder.ToString();

来自 MSDN :

For routines that perform extensive string manipulation (such as apps that modify a string numerous times in a loop), modifying a string repeatedly can exact a significant performance penalty. The alternative is to use StringBuilder, which is a mutable string class. Mutability means that once an instance of the class has been created, it can be modified by appending, removing, replacing, or inserting characters. A StringBuilder object maintains a buffer to accommodate expansions to the string. New data is appended to the buffer if room is available; otherwise, a new, larger buffer is allocated, data from the original buffer is copied to the new buffer, and the new data is then appended to the new buffer.