Question

如何以编程方式创建NSView以便用户可以使用鼠标移动其位置？我需要为视图分配哪些属性？谢谢！

    newView = [helpWindow contentView];
    [contentView addSubview:newView];
    //add properties of newView to be able to respond to touch and can be draggable

Answer 1

不幸的是，没有像setMoveByWindowBackground那样的简单方法：你可以用窗口做。您必须覆盖mouseDown：，mouseDragged：和mouseUp：并使用setFrameOrigin：基于鼠标指针的位置。为了在第一次单击内部时没有视图跳转，您还需要考虑视图的原点与第一次单击时moue指针在视图中的位置之间的偏移。这是我在一个项目中制作的一个例子，用于在父视图中移动“图块”（这是用于游戏“Upwords”的计算机版本，就像3d拼字游戏一样）。

-(void)mouseDown:(NSEvent *) theEvent{
    self.mouseLoc = [theEvent locationInWindow];
    self.movingTile = [self hitTest:self.mouseLoc]; //returns the object clicked on
    int tagID = self.movingTile.tag;
    if (tagID > 0 && tagID < 8) {
        [self.viewsList exchangeObjectAtIndex:[self.viewsList indexOfObject:self.movingTile] withObjectAtIndex: 20]; // 20 is the highest index in the array in this case
        [self setSubviews:self.viewsList]; //Reorder's the subviews so the picked up tile always appears on top
        self.hit = 1;
        NSPoint cLoc = [self.movingTile convertPoint:self.mouseLoc fromView:nil];
        NSPoint loc = NSMakePoint(self.mouseLoc.x - cLoc.x, self.mouseLoc.y - cLoc.y);
        [self.movingTile setFrameOrigin:loc];
        self.kX = cLoc.x;  //this is the x offset between where the mouse was clicked and "movingTile's" x origin
        self.kY = cLoc.y;  //this is the y offset between where the mouse was clicked and "movingTile's" y origin
    }
}

-(void)mouseDragged:(NSEvent *)theEvent {
    if (self.hit == 1) {
        self.mouseLoc = [theEvent locationInWindow];
        NSPoint newLoc = NSMakePoint(self.mouseLoc.x - self.kX, self.mouseLoc.y - self.kY);
        [self.movingTile setFrameOrigin:newLoc];
    }
}

这个例子指出了另一种可能的并发症。当你移动一个视图时，它可能看起来在其他视图下移动，所以我注意到我将移动视图作为父视图子视图的最顶层视图（viewsList是从self.subviews获取的数组）

可拖动的NSView

1 个答案: