使用圖形對象的圖片框縮放模式效果

Question

當您將圖片加載到圖片框中時，圖片放置位置會縮放，如何使用圖形對象實現同樣的效果？

Answer 1

我想你的意思是你想一些Image自己繪製在一個Rectangle和使用一些Graphics對象等，作爲PictureBox呈現其形象Zoom模式。嘗試下面的代碼。我想你想畫的Image表格，繪圖代碼應該在你的形式的Paint事件處理程序被添加在：

//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)); 
} 

要測試表單上的完美，你也應該有設置ResizeRedraw = true和啓用DoubleBuffered：

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