只有在程序运行时调整表单大小时才会发生。
我单击“ - ”并将程序最小化到任务栏，然后我看到错误/异常消息。
protected override void OnLayout(LayoutEventArgs levent)
{
base.OnLayout(levent);
if (!_addingLines)
SplitText(this.Text);
if (_backBmpBU != null)
this._backBmp = MakeBackBmp(_backBmpBU);
if (this.BitmapModus)
{
UpdateBitmap();
}
}
private void UpdateBitmap()
{
if (_lines != null && _lines.Length > 0)
{
SizeF sz = new SizeF(0, 0);
float lineOrigHeight = sz.Height;
using (Graphics g = this.CreateGraphics())
{
sz = g.MeasureString("Teststring", this.Font);
if (this._additionalSpaceBetweenLines > 0)
sz = new SizeF(sz.Width, sz.Height + this._additionalSpaceBetweenLines);
}
this._textHeight = sz.Height * _lines.Length;
if (_bmp != null)
{
_bmp.Dispose();
_bmp = null;
}
try
{
if (this._textHeight > MAXHEIGHT)
throw new Exception("Text too long, for BitmapMode.");
_bmp = new Bitmap(this.ClientSize.Width, (int)Math.Ceiling(this._textHeight));
using (Graphics g = Graphics.FromImage(_bmp))
{
//set it to value you like...
g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
g.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.None;
using (SolidBrush b = new SolidBrush(this.ForeColor))
{
for (int i = 0; i < _lines.Length; i++)
{
SolidBrush bb = b;
if (TrimText)
_lines[i] = _lines[i].Trim();
sz = g.MeasureString(_lines[i], this.Font);
lineOrigHeight = sz.Height;
if (this._additionalSpaceBetweenLines > 0)
sz = new SizeF(sz.Width, sz.Height + this._additionalSpaceBetweenLines);
_posX = 0;
if (this.TextLayoutCentered)
_posX = (this.ClientSize.Width - sz.Width) / 2.0F;
bool drect = false;
bool colw = false;
int indx = -1;
int length = 0;
string textToFind = "";
Color fc = this.ForeColor;
Color bc = Color.Transparent;
Color rc = Color.Transparent;
if (Words != null && Words.Count > 0)
{
for (int ii = 0; ii < Words.Count; ii++)
{
if (_lines[i].Contains(Words[ii].WordOrText))
{
bb = new SolidBrush(Words[ii].ForeColor);
if (Words[ii].DrawRect)
drect = true;
if (Words[ii].ColorOnlyThisWord)
colw = true;
indx = _lines[i].IndexOf(Words[ii].WordOrText);
length = Words[ii].WordOrText.Length;
textToFind = Words[ii].WordOrText;
fc = Words[ii].ForeColor;
bc = Words[ii].BackColor;
rc = Words[ii].RectColor;
drect = Words[ii].DrawRect;
}
}
}
if (colw)
{
//reset b and create a new color brush
if (bb.Equals(b) == false)
bb.Dispose();
bb = b;
string ftext = _lines[i];
float cPosX = _posX;
using (SolidBrush bbb = new SolidBrush(fc))
{
while (indx > -1)
{
if (indx > 0)
g.DrawString(ftext.Substring(0, indx), this.Font, bb, new PointF(cPosX, sz.Height * i + _additionalSpaceBetweenLines / 2F));
cPosX += g.MeasureString(ftext.Substring(0, indx), this.Font).Width;
SizeF sfWord = g.MeasureString(ftext.Substring(indx, length), this.Font);
if (bc.ToArgb().Equals(Color.Transparent.ToArgb()) == false)
{
using (SolidBrush bbbb = new SolidBrush(bc))
g.FillRectangle(bbbb, cPosX, sz.Height * i + _additionalSpaceBetweenLines / 2F, sfWord.Width, sfWord.Height);
}
g.DrawString(ftext.Substring(indx, length), this.Font, bbb, new PointF(cPosX, sz.Height * i + _additionalSpaceBetweenLines / 2F));
cPosX += sfWord.Width;
ftext = ftext.Substring(indx + length);
if (textToFind.Length > 0)
indx = ftext.IndexOf(textToFind);
else
indx = -1;
}
if (ftext.Length > 0)
g.DrawString(ftext, this.Font, bb, new PointF(cPosX, sz.Height * i + _additionalSpaceBetweenLines / 2F));
}
}
else
{
if (bc.ToArgb().Equals(Color.Transparent.ToArgb()) == false)
{
using (SolidBrush bbbb = new SolidBrush(bc))
g.FillRectangle(bbbb, _posX, sz.Height * i + _additionalSpaceBetweenLines / 2F, sz.Width, lineOrigHeight);
}
g.DrawString(_lines[i], this.Font, bb, new PointF(_posX, sz.Height * i + _additionalSpaceBetweenLines / 2F));
}
if (drect)
{
if (rc.ToArgb().Equals(Color.Transparent.ToArgb()) == false)
using (Pen p = new Pen(rc))
g.DrawRectangle(p, _posX, sz.Height * i + _additionalSpaceBetweenLines / 2F, sz.Width, lineOrigHeight);
}
if (bb.Equals(b) == false)
bb.Dispose();
if (DrawRect)
{
using (Pen p = new Pen(this.ForeColor))
{
if (DrawRectAroundText)
g.DrawRectangle(p, _posX, sz.Height * i + _additionalSpaceBetweenLines / 2F, sz.Width, lineOrigHeight);
else
g.DrawRectangle(p, 0, sz.Height * i + _additionalSpaceBetweenLines / 2F, this.ClientSize.Width - 1, lineOrigHeight);
}
}
}
}
}
}
catch (Exception ex)
{
if (_bmp != null)
{
_bmp.Dispose();
_bmp = null;
}
this.BitmapModus = false;
//MessageBox.Show(ex.Message + " switching to Dynamic-Draw-Mode.");
OnSwitchModeOnError();
}
}
}
当程序运行时，我将表单最小化到任务栏即可获得异常：
参数无效
完整的异常消息：
System.ArgumentException was caught
HResult=-2147024809
Message=Parameter is not valid.
Source=System.Drawing
StackTrace:
at System.Drawing.Bitmap..ctor(Int32 width, Int32 height, PixelFormat format)
at System.Drawing.Bitmap..ctor(Int32 width, Int32 height)
at ScrollLabelTest.ScrollLabel.UpdateBitmap() in e:\scrolllabel\ScrollLabel\ScrollLabel\ScrollLabel.cs:line 601
InnerException:
答案 0 :(得分：0)
private void picMinimize_Click(object sender, EventArgs e)
{
try
{
panelUC.Visible = false; //change visible status of your form, etc.
this.WindowState = FormWindowState.Minimized; //minimize
minimizedFlag = true; //set a global flag
}
catch (Exception)
{
}
}
private void mainForm_Resize(object sender, EventArgs e)
{
//check if form is minimized, and you know that this method is only called if and only if the form get a change in size, meaning somebody clicked in the taskbar on your application
if (minimizedFlag == true)
{
panelUC.Visible = true; //make your panel visible again! thats it
minimizedFlag = false; //set flag back
}
}