问题描述
我试图在UserControl控件上用画笔绘制。我可以绘制线条,圆圈和矩形。我不完全明白为什么我不能用画笔画画。下面的代码让我只指向MouseDown,然后它移动到MouseUp中设置的位置。在MouseMove中没有绘制内容。我想这里我不明白一些基本规则。
这段代码适用于行:
public override void Draw(Graphics graphics){
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
graphics.DrawLine(new Pen(this.Color,this.PenSize),startPoint,endPoint);
}
这段代码是我试图适应刷子的:
public override void Draw(Graphics graphics){
if(this.bitmap!= null){
graphics = Graphics.FromImage (this.bitmap);
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
graphics.DrawEllipse(new Pen(this.Color,this.PenSize),startPoint.X,startPoint.Y,
this.PenSize,this.PenSize);
graphics.DrawImage(this.bitmap,0,0);
此代码重新绘制对象列表:
private void UserControl_Paint(object sender,PaintEventArgs e){
if(ObjectsList!= null){
ObjectsList.Draw (e.Graphics);
$ b $ p
$ b 由于代码提供了我想抓取位图图像点状线条画前后。我应该这样做吗?
解决方案我不太了解您的问题,但在您的第二个代码中,他们似乎是一个失误。也许你应该试试这个:
public override void Draw(Graphics graphics)
{
if( this.bitmap!= null)
{
Graphics g = Graphics.FromImage(this.bitmap);
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
g.DrawEllipse(new Pen(this.Color,this.PenSize),startPoint.X,startPoint.Y,this.PenSize,this.PenSize);
graphics.DrawImage(this.bitmap,0,0);
$ b 否则,你在位图本身上绘制位图。希望这有助于。
I am trying to draw with brush on UserControl control. I can draw lines, circles and rectangles. I don't exactly understand why I cannot draw with brush. The code below gives me just point on MouseDown and then it moves to the position set in MouseUp. There is no content drawn during MouseMove. I suppose that I do not understand some basic rule here.
This code works for lines:
public override void Draw(Graphics graphics) {
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
graphics.DrawLine(new Pen(this.Color, this.PenSize), startPoint, endPoint);
}
This code I am trygin to adapt for brush:
public override void Draw(Graphics graphics) {
if (this.bitmap != null) {
graphics = Graphics.FromImage(this.bitmap);
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
graphics.DrawEllipse(new Pen(this.Color, this.PenSize), startPoint.X, startPoint.Y,
this.PenSize, this.PenSize);
graphics.DrawImage(this.bitmap, 0, 0);
}
}
This code repaints list of objects:
private void UserControl_Paint(object sender, PaintEventArgs e) {
if (ObjectsList != null) {
ObjectsList.Draw(e.Graphics);
}
}
As the code presents I am trying to grab bitmap image before and after point-like line drawing. Should I do it other way?
解决方案 I don't really understand your question, but in your second code their seems to be a mistake. Maybe you should try this one:
public override void Draw(Graphics graphics)
{
if (this.bitmap != null)
{
Graphics g = Graphics.FromImage(this.bitmap);
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
g.DrawEllipse(new Pen(this.Color, this.PenSize), startPoint.X, startPoint.Y, this.PenSize, this.PenSize);
graphics.DrawImage(this.bitmap, 0, 0);
}
}
Otherwise, you are drawing the bitmap on the bitmap itself. Hope this helps.
这篇关于在UserControl上使用画笔绘图的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!