C# 创建新图片框时出现问题!
首先,我很抱歉我的英语不好。现在我的C#项目(ms paint)遇到了问题。当我在图片框中打开新图片时,我绘制的最后一个形状仍然保留,直到我在此图像上绘制另一条线。这是我的代码:C# 创建新图片框时出现问题!,c#,image,bitmap,gdi+,C#,Image,Bitmap,Gdi+,首先,我很抱歉我的英语不好。现在我的C#项目(ms paint)遇到了问题。当我在图片框中打开新图片时,我绘制的最后一个形状仍然保留,直到我在此图像上绘制另一条线。这是我的代码: -划线: public Form1() { InitializeComponent(); snapshot = new Bitmap(pictureBox1.Width, pictureBox1.Height); } if (tempDraw != null)
-划线:
public Form1()
{
InitializeComponent();
snapshot = new Bitmap(pictureBox1.Width, pictureBox1.Height);
}
if (tempDraw != null)
{
tempDraw = (Bitmap)snapshot.Clone();
Graphics g = Graphics.FromImage(tempDraw);
Pen myPen = new Pen(colorPickerDropDown1.SelectedColor, 5);
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
myPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot;
g.DrawLine(myPen, pDau, pHientai);
myPen.Dispose();
e.Graphics.DrawImageUnscaled(tempDraw, 0, 0);
g.Dispose();
}
-鼠标事件:
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
paint = false;
snapshot = (Bitmap)tempDraw.Clone();
}
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
paint = true;
saved = false;
pDau = e.Location;
tempDraw = (Bitmap)snapshot.Clone();
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (paint)
{
pHientai = e.Location;
pictureBox1.Invalidate();
saved = false;
}
}
-创建新图片框:
public void New()
{
pictureBox1.Image =null;
snapshot = null;
tempDraw = null;
snapshot= new Bitmap(pictureBox1.Width, pictureBox1.Height);
}
-打开图像:
New();
snapshot = new Bitmap(openFileDialog1.FileName);
tempDraw = (Bitmap)snapshot.Clone();
pictureBox1.Image = new Bitmap(openFileDialog1.FileName);
strPath = openFileDialog1.FileName;
this.Text = strPath + " - Paint";
你能告诉我出了什么事吗?太谢谢你了 在您的第一个代码示例中,我假设整个
if
语句实际上在表单的Paint
事件中,是否正确?像这样:
private void Form_Paint(object sender, PaintEventArgs e)
{
if (tempDraw != null)
{
tempDraw = (Bitmap)snapshot.Clone();
Graphics g = Graphics.FromImage(tempDraw);
Pen myPen = new Pen(colorPickerDropDown1.SelectedColor, 5);
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
myPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot;
g.DrawLine(myPen, pDau, pHientai);
myPen.Dispose();
e.Graphics.DrawImageUnscaled(tempDraw, 0, 0);
g.Dispose();
}
}
如果是这样,请考虑调用<代码> E.Case.清除(这个.BuffCor)< /C> >以其自己的背景颜色清除窗体。这将有效地删除您绘制的任何内容。此外,如果创建任何一个方法抛出异常,请考虑使用< <代码>使用“<代码>语句”来保护您。我会重写你的
如果声明如下:
if (tempDraw != null)
{
tempDraw = (Bitmap)snapshot.Clone();
using (Graphics g = Graphics.FromImage(tempDraw))
using (Pen myPen = new Pen(colorPickerDropDown1.SelectedColor, 5))
{
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
myPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot;
g.DrawLine(myPen, pDau, pHientai);
e.Graphics.Clear(this.BackColor); // clear any drawing on the form
e.Graphics.DrawImageUnscaled(tempDraw, 0, 0);
}
}
首先,感谢您的回复。但这个“如果”的说法实际上是在picturebox_paint事件中出现的。我在Form1中添加了一个图片框,并在上面绘制。然后,您的代码只需将我的picturebox颜色更改为与表单背景相同的颜色。我的问题是,当我在picturebox上画了一些东西后,我从电脑上打开了新的图像,我画的最后一个形状没有消失,直到我在picturebox上画了其他东西,它才消失。picturebox
不是用来画画的。它用于显示图像,通常来自文件。直接在表格
或面板
上绘制。