302

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?

Onik
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Fahad Ali
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5 Answers5

667

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
Rich Schuler
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15

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).

shoe
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13
  1. you need to create and id for the buttons you need to refference: btn1.setId(1);
  2. 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 this LayoutParams object.
camelCaseCoder
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codeScriber
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  • I would highly appreciate any piece of code. I dont find any method in button. – Fahad Ali Jan 09 '11 at 11:30
  • Setting id doesn't help since it's expecting a real resource id instead of just a number since setId is being annotated with @IdRes. – Kevin Tan May 20 '15 at 06:45
  • that's new then, in the past you could take a resource number from layouts for example and use it as a base for resource id that will not collide.i guess google must have blocked that/ – codeScriber Jun 25 '15 at 19:41
2

Kotlin version:

Use these extensions with infix functions that simplify later calls

infix fun View.below(view: View) {
    (this.layoutParams as? RelativeLayout.LayoutParams)?.addRule(RelativeLayout.BELOW, view.id)
}

infix fun View.leftOf(view: View) {
    (this.layoutParams as? RelativeLayout.LayoutParams)?.addRule(RelativeLayout.LEFT_OF, view.id)
}

infix fun View.alightParentRightIs(aligned: Boolean) {
    val layoutParams = this.layoutParams as? RelativeLayout.LayoutParams
    if (aligned) {
        (this.layoutParams as? RelativeLayout.LayoutParams)?.addRule(RelativeLayout.ALIGN_PARENT_RIGHT)
    } else {
        (this.layoutParams as? RelativeLayout.LayoutParams)?.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, 0)
    }
    this.layoutParams = layoutParams
}

Then use them as infix functions calls:

view1 below view2
view1 leftOf view2
view1 alightParentRightIs true

Or you can use them as normal functions:

view1.below(view2)
view1.leftOf(view2)
view1.alightParentRightIs(true)
Mahmoud
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1

In Kotlin:

val params = mBinding.tvTotalAmount.layoutParams as RelativeLayout.LayoutParams

params.addRule(RelativeLayout.ALIGN_PARENT_END)

mBinding.tvTotalAmount.layoutParams = params

Ashraf Amin
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