Question

我正在使用以下代码制作可调节高度且可垂直对齐的文本框。我应该这样做的原因是因为虽然我可以使winform文本框高度可调，但我仍然无法垂直对齐文本框中的文本。所以我决定要绘制文本OnPaint事件。文本框现在显示正确的对齐方式，但光标仍位于文本框的顶部。有没有办法控制这个位置？

public class TextBoxHeightAdjustable : System.Windows.Forms.TextBox
{

    public TextBoxHeightAdjustable()
    {
        this.AutoSize = false;
        this.TextAlign = System.Windows.Forms.HorizontalAlignment.Center;
        this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.OptimizedDoubleBuffer | ControlStyles.ResizeRedraw, true);
    }
    protected override void OnPaint(PaintEventArgs e)
    {
        // This never runs no matter what I try!
        base.OnPaint(e);
        // Create a StringFormat object with the each line of text, and the block 
        // of text centered on the page.
        StringFormat stringFormat = new StringFormat();
        stringFormat.Alignment = StringAlignment.Center;
        stringFormat.LineAlignment = StringAlignment.Center;

        e.Graphics.DrawString(Text, Font, new SolidBrush(ForeColor), ClientRectangle, stringFormat);
    }
}

Answer 1

尽管Hans的建议，我继续说，因为文本框将包含简单的类似数字的文本。正如汉斯所说，我们没有太多选择来处理原始光标和生动的显示文本。因此，我使用以下扩展方法并禁用双击和按键更新来隐藏它们。

    [DllImport("user32.dll")]
    static extern bool HideCaret(IntPtr hWnd);
    public static void HideCaret(this TextBox textBox)
    {
        HideCaret(textBox.Handle);
    }

所以最终跟随代码的目的是为了我的目的，但我不能说它是完整的。我仍然可以弄清楚如何绘制自己的光标。希望这有助于其他类似问题。

public class TextBoxHeightAdjustable : System.Windows.Forms.TextBox
{
    const int WM_DBLCLICK = 0xA3;
    const int WM_LBUTTONDBLCLK = 0x203;


    public TextBoxHeightAdjustable() : base()
    {
        this.AutoSize = false;
        this.TextAlign = System.Windows.Forms.HorizontalAlignment.Center;
        this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.OptimizedDoubleBuffer | ControlStyles.ResizeRedraw, true);
    }
    protected override void OnKeyPress(KeyPressEventArgs e)
    {
        //base.OnKeyPress(e);
        if (e.KeyChar == (char)Keys.Back)
        {
            Text = Text.Remove(Text.Length-1);
        } 
        else
        {
            Text += e.KeyChar;
        }
        e.Handled = true;
    }
    protected override void WndProc(ref Message m)
    {
        if ((m.Msg == WM_DBLCLICK) || (m.Msg == WM_LBUTTONDBLCLK))
        {
        }
        else
        {
            base.WndProc(ref m);
        }
    }
    protected override void OnTextChanged(System.EventArgs args)
    {
        //KeyEventArgs kpe = (KeyEventArgs) args;
        //this.Font = new Font(this.Font.FontFamily, 0);
        using (Graphics g = this.CreateGraphics())
        {
            g.FillRectangle(Brushes.White, ClientRectangle);
            StringFormat stringFormat = new StringFormat();
            stringFormat.Alignment = StringAlignment.Center;
            stringFormat.LineAlignment = StringAlignment.Center;
            g.DrawString(Text, Font, new SolidBrush(ForeColor), ClientRectangle, stringFormat);

        }
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        this.HideCaret();
        e.Graphics.FillRectangle(Brushes.White, ClientRectangle);
        // This never runs no matter what I try!
        //base.OnPaint(e);
        // Create a StringFormat object with the each line of text, and the block 
        // of text centered on the page.
        StringFormat stringFormat = new StringFormat();
        stringFormat.Alignment = StringAlignment.Center;
        stringFormat.LineAlignment = StringAlignment.Center;

        e.Graphics.DrawString(Text, Font, new SolidBrush(ForeColor), ClientRectangle, stringFormat);
    }
}

如何在文本框中设置光标的位置

1 个答案: