我想拖动一个视图。到目前为止,我尝试使用 LinearLayout 和边距以及 AbsoluteLayout。
绝对布局示例:
button.Touch = (clickedView, motionEvent) =>
{
Button b = (Button)clickedView;
if (motionEvent.Action == MotionEventActions.Move)
{
AbsoluteLayout.LayoutParams layoutParams = new AbsoluteLayout.LayoutParams(100, 35, (int)motionEvent.GetX(), (int)motionEvent.GetY());
b.LayoutParameters = layoutParams;
}
return true;
};
在我尝试的每一种情况下,我都有一种古玩行为。这就是为什么。我拖动的视图跟随我的手指,但总是在两个位置之间跳转。一个位置击中我的手指,另一个位置在我手指左上角的某个位置。如果我只是将当前位置写入文本视图(不移动视图),则坐标的行为符合预期。但是,如果我也在移动视图,它们会再次跳跃。我怎样才能避免这种情况?
编辑:我对我的问题使用了声音评论来实现对 monodroid 的有效拖动(它是为链接站点中的 Java/Android SDK 完成的)。也许有一天其他人有兴趣这样做,所以这是我的解决方案:
[Activity(Label = "Draging", MainLauncher = true, Icon = "@drawable/icon")]
public class Activity1 : Activity
{
private View selectedItem = null;
private int offset_x = 0;
private int offset_y = 0;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
SetContentView(Resource.Layout.Main);
ViewGroup vg = (ViewGroup)FindViewById(Resource.Id.vg);
vg.Touch = (element, motionEvent) =>
{
switch (motionEvent.Action)
{
case MotionEventActions.Move:
int x = (int)motionEvent.GetX() - offset_x;
int y = (int)motionEvent.GetY() - offset_y;
int w = WindowManager.DefaultDisplay.Width - 100;
int h = WindowManager.DefaultDisplay.Height - 100;
if (x > w)
x = w;
if (y > h)
y = h;
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
new ViewGroup.MarginLayoutParams(
LinearLayout.LayoutParams.WrapContent,
LinearLayout.LayoutParams.WrapContent));
lp.SetMargins(x, y, 0, 0);
selectedItem.LayoutParameters = lp;
break;
default:
break;
}
return true;
};
ImageView img = FindViewById<ImageView>(Resource.Id.img);
img.Touch = (element, motionEvent) =>
{
switch (motionEvent.Action)
{
case MotionEventActions.Down:
offset_x = (int)motionEvent.GetX();
offset_y = (int)motionEvent.GetY();
selectedItem = element;
break;
default:
break;
}
return false;
};
}
}