Android - Use of view.setX() and setY in api 8

问题:

i am working on android api8. i want to position/place a view on screen dynamically. but to use setX and setY we need API level 11 and above. how can we use it in API 8 or is there any alternative for this? need help

回答1:

You can do this by using the LayoutParams. These can be added to components of the android interface to set their bounds and position.

An example (setting the LayoutParams on a child view of a RelativeLayout)

RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT); //The WRAP_CONTENT parameters can be replaced by an absolute width and height or the FILL_PARENT option)
params.leftMargin = 50; //Your X coordinate
params.topMargin = 60; //Your Y coordinate
childView.setLayoutParams(params);

Take note that the type of the LayoutParams must be equal to the parent of the childview you want to add them to. (LinearLayout.LayoutParams for a LinearLayout , RelativeLayout.LayoutParams for a RelativeLayout etc.).

Also, instead of childView.setLayoutParams(params); you can also use parentView.addView(childView,params); to set the Layoutparams when the item is added to the parent container.

NOTE! The values for the coordinates are in pixels. Since it's best practice to use DP values to define your interface sizes you could use this piece of code to convert dp to pixels:

private int getPixels(int dipValue){ 
     Resources r = getResources();
     int px = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dipValue,   r.getDisplayMetrics());
     return px; 
}

回答2:

aditionally to above(Leon Lucardie's answer)if the view is a GroupView and when its being supposed the view edges to go outside the screen , you also have to put :

params.rightMargin=currentRightMargin -yourX;
params.bottomMargin=currentBottomMargin -yourY;

to avoid distortions within view's inner layout

回答3:

You can use http://nineoldandroids.com/ and have API support from level 1, in this way:

ViewPropertyAnimator.animate(view).translationYBy(-yourY).setDuration(0);