获取相对于根布局的View坐标

Question

我可以获取相对于Android中我的Activity的根布局的View的x和y位置吗？

Answer 1

这是一种解决方案,但由于API会随着时间的推移而发生变化,并且可能还有其他方法,因此请务必查看其他答案.一个声称更快,另一个声称更容易.

private int getRelativeLeft(View myView) {
    if (myView.getParent() == myView.getRootView())
        return myView.getLeft();
    else
        return myView.getLeft() + getRelativeLeft((View) myView.getParent());
}

private int getRelativeTop(View myView) {
    if (myView.getParent() == myView.getRootView())
        return myView.getTop();
    else
        return myView.getTop() + getRelativeTop((View) myView.getParent());
}

如果有效,请告诉我.

它应该递归地添加每个父容器的顶部和左侧位置.您也可以使用Pointif 实现它.

Answer 2

Android API已经提供了实现这一目标的方法.试试这个:

Rect offsetViewBounds = new Rect();
//returns the visible bounds
childView.getDrawingRect(offsetViewBounds);
// calculates the relative coordinates to the parent
parentViewGroup.offsetDescendantRectToMyCoords(childView, offsetViewBounds); 

int relativeTop = offsetViewBounds.top;
int relativeLeft = offsetViewBounds.left;

这是文档

Answer 3

请使用view.getLocationOnScreen(int[] location);(参见Javadocs).答案是整数数组(x = location[0]和y = location[1]).

Answer 4

无需手动计算.

只需像这样使用getGlobalVisibleRect:

Rect myViewRect = new Rect();
myView.getGlobalVisibleRect(myViewRect);
float x = myViewRect.left;
float y = myViewRect.top;

另请注意,对于中心坐标,而不是:

...
float two = (float) 2
float cx = myViewRect.left + myView.getWidth() / two;
float cy = myViewRect.top + myView.getHeight() / two;

你可以这样做:

float cx = myViewRect.exactCenterX();
float cy = myViewRect.exactCenterY();

Answer 5

View rootLayout = view.getRootView().findViewById(android.R.id.content);

int[] viewLocation = new int[2]; 
view.getLocationInWindow(viewLocation);

int[] rootLocation = new int[2];
rootLayout.getLocationInWindow(rootLocation);

int relativeLeft = viewLocation[0] - rootLocation[0];
int relativeTop  = viewLocation[1] - rootLocation[1];

首先,我获得根布局,然后计算与视图的坐标差异.
您也可以使用getLocationOnScreen()而不是getLocationInWindow().

Answer 6

你可以用`

view.getLocationOnScreen(int [] location)

;`正确获取视图的位置.

但有一个捕获如果你使用它之前的布局已经膨胀,你会得到错误的位置.

解决这个问题的方法是这样添加ViewTreeObserver: -

全局声明数组以存储视图的xy位置

 int[] img_coordinates = new int[2];

然后添加ViewTreeObserver你的父布局来获得布局膨胀的回调,然后才获取视图的位置,否则你会得到错误的xy坐标

  // set a global layout listener which will be called when the layout pass is completed and the view is drawn
            parentViewGroup.getViewTreeObserver().addOnGlobalLayoutListener(
                    new ViewTreeObserver.OnGlobalLayoutListener() {
                        public void onGlobalLayout() {
                            //Remove the listener before proceeding
                            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                                parentViewGroup.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                            } else {
                                parentViewGroup.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                            }

                            // measure your views here
                            fab.getLocationOnScreen(img_coordinates);
                        }
                    }
            );

然后像这样使用它

xposition = img_coordinates[0];
yposition =  img_coordinates[1];