画板上 一边拖鼠标 一边画椭圆 的动态画圆是怎么实现的呢? 画板上 一边拖鼠标 一边画椭圆 的动态画圆是怎么实现的呢? 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 bool isStartToDraw = false; Point startPoint = new Point(); private void Form1_MouseDown(object sender, MouseEventArgs e) { isStartToDraw = true; startPoint = e.Location; } private void Form1_MouseMove(object sender, MouseEventArgs e) { if (isStartToDraw) { Graphics graphics = this.CreateGraphics(); graphics.DrawLine(Pens.Black, startPoint, e.Location); startPoint = e.Location; } } private void Form1_MouseUp(object sender, MouseEventArgs e) { isStartToDraw = false; } 2L正解,做标志量,在MOVE函数中不停画圆 Point startPoint = new Point(); private void Form1_MouseDown(object sender, MouseEventArgs e) { startPoint = e.Location; } private void Form1_MouseUp(object sender, MouseEventArgs e) { Graphics graphics = this.CreateGraphics(); graphics.DrawEllipse(Pens.Red, startPoint.X, startPoint.Y, e.X, e.Y); } dataset导出到excel,发布后没反应 关于C++垃圾处理机制的问题 关于C#高速处理的问题 如何实现将一个数据表的某一属性名的值添加到DropDownList中显示? listbox如何设置行高? 还有如何在每一行的文字前加一个图标? 怎样杀死这个线程? C#调用存储过程“必须声明标量变量@domain_no" 有关mysql参数化查询的问题 C# 滚屏问题 谁能帮我看下这个传真函数,是什么问题 后台往前台输出table 代替gridview 关于清楚控件值
Point startPoint = new Point(); private void Form1_MouseDown(object sender, MouseEventArgs e)
{
isStartToDraw = true;
startPoint = e.Location;
} private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (isStartToDraw)
{
Graphics graphics = this.CreateGraphics();
graphics.DrawLine(Pens.Black, startPoint, e.Location);
startPoint = e.Location;
}
} private void Form1_MouseUp(object sender, MouseEventArgs e)
{
isStartToDraw = false;
}
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
startPoint = e.Location;
} private void Form1_MouseUp(object sender, MouseEventArgs e)
{
Graphics graphics = this.CreateGraphics();
graphics.DrawEllipse(Pens.Red, startPoint.X, startPoint.Y, e.X, e.Y);
}