在NSScrollView中居中放置NSView

Question

如何在NSScrollView中像「預覽」一樣將NSView居中？

Answer 1

閱讀滾動到特定位置的Scroll View Programming Guide部分。這裏有頂部或底部的例子。您只需更改數學計算基於您的NSView中間的原點。例如：

-(void)scrollToCenter:(NSScrollView*)scrollView 
{ 
    const CGFloat midX = NSMidX([[scrollView documentView] bounds]); 
    const CGFloat midY = NSMidY([[scrollView documentView] bounds]); 

    const CGFloat halfWidth = NSWidth([[scrollView contentView] frame])/2.0; 
    const CGFloat halfHeight = NSHeight([[scrollView contentView] frame])/2.0; 

    NSPoint newOrigin; 
    if([[scrollView documentView] isFlipped]) 
    { 
     newOrigin = NSMakePoint(midX - halfWidth, midY + halfHeight); 
    } 
    else 
    { 
     newOrigin = NSMakePoint(midX - halfWidth, midY - halfHeight); 
    } 

    [[scrollView documentView] scrollPoint:newOrigin]; 
}