使用图形对象的图片框缩放模式效果

Question

当您将图片加载到图片框中时，图片放置位置会缩放，如何使用图形对象实现同样的效果？

Answer 1

我想你的意思是你想一些Image自己绘制在一个Rectangle和使用一些Graphics对象等，作为PictureBox呈现其形象Zoom模式。尝试下面的代码。我想你想画的Image表格，绘图代码应该在你的形式的Paint事件处理程序被添加在：

//The Rectangle (corresponds to the PictureBox.ClientRectangle) 
//we use here is the Form.ClientRectangle 
//Here is the Paint event handler of your Form1 
private void Form1_Paint(object sender, EventArgs e){ 
    ZoomDrawImage(e.Graphics, yourImage, ClientRectangle); 
} 
//use this method to draw the image like as the zooming feature of PictureBox 
private void ZoomDrawImage(Graphics g, Image img, Rectangle bounds){ 
    decimal r1 = (decimal) img.Width/img.Height; 
    decimal r2 = (decimal) bounds.Width/bounds.Height; 
    int w = bounds.Width; 
    int h = bounds.Height; 
    if(r1 > r2){ 
    w = bounds.Width; 
    h = (int) (w/r1); 
    } else if(r1 < r2){ 
    h = bounds.Height; 
    w = (int) (r1 * h); 
    } 
    int x = (bounds.Width - w)/2; 
    int y = (bounds.Height - h)/2; 
    g.DrawImage(img, new Rectangle(x,y,w,h)); 
} 

要测试表单上的完美，你也应该有设置ResizeRedraw = true和启用DoubleBuffered：

public Form1(){ 
    InitializeComponent(); 
    ResizeRedraw = true; 
    DoubleBuffered = true; 
}