如何设置限制图像缩放wp8？

Question

I want to set limit on zoom so that after a certain level of zoom image should not zoomed further. Here is my code.

    private void OnPinchDelta(object sender, PinchGestureEventArgs e)
    {
        if (transform.ScaleX== 1)
        {
        }
        else
        {
            transform.Rotation = angle + e.TotalAngleDelta;
            transform.ScaleX = scale * e.DistanceRatio;
            transform.ScaleY = scale * e.DistanceRatio;
        }
    }

After a certain level of zoom the image is getting disabled. Can anyone suggest me how to limit this zoom. Thanks in advance.

Answer 1

Just declare maximum value and compare it with a new scale. Here's my example:

private readonly double maxScale = 5;

private void OnPinchDelta(object sender, PinchGestureEventArgs e)
{
    if (transform.ScaleX == 1)
    {
    }
    else
    {
        transform.Rotation = angle + e.TotalAngleDelta;
        double newScale = scale * e.DistanceRatio;
        if (newScale > maxScale)
            newScale = maxScale;
        transform.ScaleX = newScale;
        transform.ScaleY = newScale;
    }
}

Answer 2

最后，有效的代码在这里。

private double maxScale =10; private double minScale =0.2; private void OnPinchDelta(object sender, PinchGestureEventArgs e) { transform.Rotation = angle + e.TotalAngleDelta; double newScale = scale * e.DistanceRatio; if (newScale > maxScale) newScale = maxScale; if (newScale < minScale) newScale = minScale; transform.ScaleX = newScale; transform.ScaleY = newScale; }