"HOW TO: Create a Smooth Progress Bar in Visual C# .NET"的学习笔记

王朝c#·作者佚名  2006-01-09
窄屏简体版  字體: |||超大  

现在使用.net老是感觉.net自带的控件的很多的功能不尽人意,所以参考微软的学习资料,感觉自己编一个符合自己要求的Control还是很简单的

HOW TO: Create a Smooth Progress Bar in Visual C# .NET就是叫我们怎么样做自己的控件的

其实做好其中的几个重要函数的重写工作就可以了

例如OnResize(),OnPaint()

protected override void OnPaint(PaintEventArgs e)

{

Graphics g = e.Graphics;

SolidBrush brush = new SolidBrush(BarColor);

float percent = (float)(val - min) / (float)(max - min);

Rectangle rect = this.ClientRectangle;

// Calculate area for drawing the progress.

rect.Width = (int)((float)rect.Width * percent);

// Draw the progress meter.

g.FillRectangle(brush, rect);

// Draw a three-dimensional border around the control.

Draw3DBorder(g);

// Clean up.

brush.Dispose();

g.Dispose();

}

private void Draw3DBorder(Graphics g)

{

int PenWidth = (int)Pens.White.Width;

g.DrawLine(Pens.DarkGray,

new Point(this.ClientRectangle.Left, this.ClientRectangle.Top),

new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Top));

g.DrawLine(Pens.DarkGray,

new Point(this.ClientRectangle.Left, this.ClientRectangle.Top),

new Point(this.ClientRectangle.Left, this.ClientRectangle.Height - PenWidth));

g.DrawLine(Pens.White,

new Point(this.ClientRectangle.Left, this.ClientRectangle.Height - PenWidth),

new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Height - PenWidth));

g.DrawLine(Pens.White,

new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Top),

new Point(this.ClientRectangle.Width - PenWidth, this.ClientRectangle.Height - PenWidth));

}

这一段程序就是自己绘制控件外观的,很简单吧

可以自己添加控件的事件,特性(property),方法

public int Minimum

{

get

{

return min;

}

set

{

// Prevent a negative value.

if (value < 0)

{

min = 0;

}

// Make sure that the minimum value is never set higher than the maximum value.

if (value > max)

{

min = value;

min = value;

}

// Ensure value is still in range

if (val < min)

{

val = min;

}

// Invalidate the control to get a repaint.

this.Invalidate();

}

}

public int Maximum

{

get

{

return max;

}

set

{

// Make sure that the maximum value is never set lower than the minimum value.

if (value < min)

{

min = value;

}

max = value;

// Make sure that value is still in range.

if (val > max)

{

val = max;

}

// Invalidate the control to get a repaint.

this.Invalidate();

}

}

public int Value

{

get

{

return val;

}

set

{

int oldValue = val;

// Make sure that the value does not stray outside the valid range.

if (value < min)

{

val = min;

}

else if (value > max)

{

val = max;

}

else

{

val = value;

}

// Invalidate only the changed area.

float percent;

Rectangle newValueRect = this.ClientRectangle;

Rectangle oldValueRect = this.ClientRectangle;

// Use a new value to calculate the rectangle for progress.

percent = (float)(val - min) / (float)(max - min);

newValueRect.Width = (int)((float)newValueRect.Width * percent);

// Use an old value to calculate the rectangle for progress.

percent = (float)(oldValue - min) / (float)(max - min);

oldValueRect.Width = (int)((float)oldValueRect.Width * percent);

Rectangle updateRect = new Rectangle();

// Find only the part of the screen that must be updated.

if (newValueRect.Width > oldValueRect.Width)

{

updateRect.X = oldValueRect.Size.Width;

updateRect.Width = newValueRect.Width - oldValueRect.Width;

}

else

{

updateRect.X = newValueRect.Size.Width;

updateRect.Width = oldValueRect.Width - newValueRect.Width;

}

updateRect.Height = this.Height;

// Invalidate the intersection region only.

this.Invalidate(updateRect);//注意这是强制重绘的,一定要有,不然图形不会改变的^_^

}

}

public Color ProgressBarColor//控制颜色的

{

get

{

return BarColor;

}

set

{

BarColor = value;

// Invalidate the control to get a repaint.

this.Invalidate();

}

}

这是自己添加的特性(property)

虽然这是一个很小的示例,但是向我们这种菜鸟展示的.net的强大.通过这种方式我们完全可以做到开发符合自己要求的控件.

程序来自微软网站

 
 
 
免责声明:本文为网络用户发布,其观点仅代表作者个人观点,与本站无关,本站仅提供信息存储服务。文中陈述内容未经本站证实,其真实性、完整性、及时性本站不作任何保证或承诺,请读者仅作参考,并请自行核实相关内容。
 
 
© 2005- 王朝網路 版權所有 導航