问题
I have a relative layout which I am creating programmatically:
RelativeLayout layout = new RelativeLayout( this );
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT);
Now I have two buttons which I want to add in this relative layout. But the problem is both buttons are being shown on the left of the RelatiiveLayout overlapping on each other.
buttonContainer.addView(btn1);
buttonContainer.addView(btn2);
Now I want to know how can I programmatically set the the android:layout_alignParentRight=\"true
\"
or android:layout_toLeftOf=\"@id/btn\"
attribute of buttons as we do in the xml?
回答1:
You can access any LayoutParams
from code using View.getLayoutParams
. You just have to be very aware of what LayoutParams
your accessing. This is normally achieved by checking the containing ViewGroup
if it has a LayoutParams
inner child then that's the one you should use. In your case it's RelativeLayout.LayoutParams
. You'll be using RelativeLayout.LayoutParams#addRule(int verb) and RelativeLayout.LayoutParams#addRule(int verb, int anchor)
You can get to it via code:
RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams)button.getLayoutParams();
params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
params.addRule(RelativeLayout.LEFT_OF, R.id.id_to_be_left_of);
button.setLayoutParams(params); //causes layout update
回答2:
- you need to create and id for the
buttons you need to refference:
btn1.setId(1);
- you can use the params variable to
add parameters to your layout, i
think the method is
addRule()
, check out the android java docs for thisLayoutParams
object.
回答3:
For adding a RelativeLayout
attribute whose value is true or false use 0
for false and RelativeLayout.TRUE
for true:
RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) button.getLayoutParams()
params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, RelativeLayout.TRUE)
It doesn't matter whether or not the attribute was already added, you still use addRule(verb, subject)
to enable/disable it. However, post-API 17 you can use removeRule(verb)
which is just a shortcut for addRule(verb, 0)
.
来源:https://stackoverflow.com/questions/4638832/how-to-programmatically-set-the-layout-align-parent-right-attribute-of-a-button