在richTextBox C#中为特定的文本行着色[重复]

Question

我是新来的，也是 C# 的新手。我基本上只想在我的报告中为最高温度（单行）上色，但我已经尝试了这里的所有编码，但没有任何效果。有人可以帮帮我吗？这是我的编码，比较两个城市的预测。如果有其他更简单的方法可以使用 listBox 等其他功能，请告诉我。

如果你看到图片，我现在基本上只是用星号来表示更高的温度。

输出：

New output

我的代码：

private void getComparison()
{

    this.richTextBox1.Text = ("Start Date:  " + dateTimePicker3.Value.ToString());
    this.richTextBox1.Text = ("COMPARE MULTIPLE CITIES FOR THE WEEK" + Environment.NewLine + "\n\n");

    for (int j = 0; j < 7; j++)
    {
        tempCity1 = Convert.ToInt32(a.getMaxi()[comboBox2.SelectedIndex, j].ToString());
        tempCity2 = Convert.ToInt32(a.getMaxi()[comboBox1.SelectedIndex, j].ToString());

        //City 1
        this.richTextBox1.Text = ("------------------------------------------");
        this.richTextBox1.Text = ("Day:  " + a.getDate(j).ToString());
        this.richTextBox1.Text = ("------------------------------------------");
        this.richTextBox1.Text = ("City:  " + arrCities[comboBox2.SelectedIndex]);
        this.richTextBox1.Text = ("Minimum Temperature:  " + a.getMini()[comboBox2.SelectedIndex, j].ToString() + "°C");
        
        
        
        if (tempCity1 < tempCity2)
        {
            this.richTextBox1.Text =("Maximum Temperature: " + a.getMaxi()[comboBox2.SelectedIndex, j].ToString() + "°C");
            //richTextBox1.SelectionColor = Color.Red;
        }
        else
        {
            this.richTextBox1.Text = ("***Maximum Temperature: " + a.getMaxi()[comboBox2.SelectedIndex, j].ToString() + "°C");
            //richTextBox1.SelectionBackColor = Color.Blue;
        }

        this.richTextBox1.Text = ("Precipitation:  " + a.getPrecip()[comboBox2.SelectedIndex, j].ToString() + "%");
        this.richTextBox1.Text = ("Humidity:  " + a.getHumid()[comboBox2.SelectedIndex, j].ToString() + "%");
        this.richTextBox1.Text = ("Wind speed:  " + a.getWindspeed()[comboBox2.SelectedIndex, j].ToString() + "km / h");
        this.richTextBox1.Text = ("" + Environment.NewLine + "\n\n");

        //City 2
        this.richTextBox1.Text = ("City:  " + arrCities[comboBox1.SelectedIndex]);
        this.richTextBox1.Text = ("Minimum Temperature:  " + a.getMini()[comboBox1.SelectedIndex, j].ToString() + "°C");

        if (tempCity1 > tempCity2)
        {
            this.richTextBox1.Text=("Maximum Temperature: " +  a.getMaxi()[comboBox1.SelectedIndex, j].ToString() + "°C");
            //richTextBox1.SelectionColor = Color.Red;
        }
        else
        {
            this.richTextBox1.Text = ("**Maximum Temperature:" + a.getMaxi()[comboBox1.SelectedIndex, j].ToString() + "°C");
            //richTextBox1.SelectionColor = Color.Blue;
        }


        //("Maximum Temperature:  " + a.getMaxi()[comboBox1.SelectedIndex, j].ToString() + "°C");
        this.richTextBox1.Text = ("Precipitation:  " + a.getPrecip()[comboBox1.SelectedIndex, j].ToString() + "%");
        this.richTextBox1.Text = ("Humidity:  " + a.getHumid()[comboBox1.SelectedIndex, j].ToString() + "%");
        this.richTextBox1.Text = ("Wind speed:  " + a.getWindspeed()[comboBox1.SelectedIndex, j].ToString() + "km / h");

    }

谢谢你:)

Answer 1

要为列表框中的项目着色，您需要重写“ListBox.DrawItem”事件。

只需将其复制到您的课程中即可：

private readonly List<Color> colors = new List<Color>();
private readonly List<string> texts = new List<string>();
private void ListBox_Draw(object sender, DrawItemEventArgs e)
{
    if (e.Index == -1) return;
    e.DrawBackground();
    Graphics g = e.Graphics;
    //if the item is the maximum temperature item, draw with your color
    g.FillRectangle(new SolidBrush(colors[e.Index]), e.Bounds);
    g.DrawString(texts[e.Index], e.Font, new SolidBrush(e.ForeColor), e.Bounds);
    e.DrawFocusRectangle();
}

private void AddItem(string text, Color color)
{
    colors.Add(color);
    texts.Add(text);
    listBox1.Items.Add("");
}

并将其复制到 Form_Load 函数中：

listBox1.DrawMode = DrawMode.OwnerDrawVariable;//draw items manually
listBox1.DrawItem += ListBox_Draw;//subscribe to draw event

使用方法：

您只需使用 AddItem(your_text, the_color_of_this_item)，而不是使用 listBox1.Items.Add()

例子：

AddItem("Item 1", Color.Red);
AddItem("This is item 2", Color.White);
AddItem("Hello from item 3", Color.Blue);
AddItem("I am item 4", Color.Purple);
AddItem("is it item 5?", Color.Yellow);
AddItem("Im the last item :(", Color.Green);

这就是示例的样子：

希望这会有所帮助！