C# richTextBox如何控制行高的问题

C#设置richtextBox行高的方法

最新推荐文章于 2021-09-21 20:11:04 发布

原创最新推荐文章于 2021-09-21 20:11:04 发布 · 4k 阅读

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文章标签：

#c# #object #user #byte #测试 #struct

本文介绍了如何在C#中控制richtextBox控件的行高。通过使用WM_USER、EM_GETPARAFORMAT和EM_SETPARAFORMAT等消息，结合PARAFORMAT2结构体，可以设置dyLineSpacing属性来调整行间距，从而实现行高的控制。示例代码展示了具体的实现过程。

richTextBox控件是一个active的控件，却没有一个明显的控制文字行高的属性，于是在网上google了一下，果然网上高手众多，找到了示例代码，一测试，真管用，呵呵。下边是我的测试代码：

    public partial class Form1 : Form
    {
        public const int WM_USER = 0x0400;
        public const int EM_GETPARAFORMAT = WM_USER + 61;
        public const int EM_SETPARAFORMAT = WM_USER + 71;
        public const long MAX_TAB_STOPS = 32;
        public const uint PFM_LINESPACING = 0x00000100;
        [StructLayout(LayoutKind.Sequential)]
        private struct PARAFORMAT2
        {
            public int cbSize;
            public uint dwMask;
            public short wNumbering;
            public short wReserved;
            public int dxStartIndent;
            public int dxRightIndent;
            public int dxOffset;
            public short wAlignment;
            public short cTabCount;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
            public int[] rgxTabs;
            public int dySpaceBefore;
            public int dySpaceAfter;
            public int dyLineSpacing;
            public short sStyle;
            public byte bLineSpacingRule;
            public byte bOutlineLevel;
            public short wShadingWeight;
            public short wShadingStyle;
            public short wNumberingStart;
            public short wNumberingStyle;
            public short wNumberingTab;
            public short wBorderSpace;
            public short wBorderWidth;
            public short wBorders;
        }

        public Form1()
        {
            InitializeComponent();
        }

        private void MenuItemExit_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

        private void MenuItemOpen_Click(object sender, EventArgs e)
        {
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                richTextBox1.LoadFile(openFileDialog1.FileName, RichTextBoxStreamType.PlainText);
            }
        }

[DllImport("user32", CharSet = CharSet.Auto)]
private static extern IntPtr SendMessage(HandleRef hWnd, int msg, int wParam, ref PARAFORMAT2 lParam);

        private void Form1_Load(object sender, EventArgs e)
        {
            PARAFORMAT2 fmt = new PARAFORMAT2();
            fmt.cbSize = Marshal.SizeOf(fmt);
            fmt.bLineSpacingRule = 4;
            fmt.dyLineSpacing = 400;//可修改的行高数值。我使用的300，感觉较为合适，这个500有点宽了！
            fmt.dwMask = PFM_LINESPACING;
            SendMessage(new HandleRef(this.richTextBox1, richTextBox1.Handle), EM_SETPARAFORMAT, 4, ref fmt);

            richTextBox1.BackColor = Color.FromArgb(231, 244, 254);
        }
    }