How to set layout_weight attribute dynamically from code?

Question

How can I set the value for the attribute layout_weight for button in android dynamically from java code ?

It'll be very similar to this question/answer: http://stackoverflow.com/questions/4638832/how-to-programmatically-set-the-layout-align-parent-right-attribute-of-a-button-i/4639012#4639012 and this one: http://stackoverflow.com/questions/4637233/how-to-set-layout-span-through-code/4637266#4637266 — Rich Schuler, Jan 09 '11 at 19:07
If you have already defined view in layout(xml) file, then creating new LayoutParams overwrites other params defined in xml file. So first you should use "getLayoutParams". See full answer http://stackoverflow.com/questions/4641072/how-to-set-layout-weight-attribute-dynamically-from-code/38011495#38011495 — Shirish Herwade, Jun 24 '16 at 10:44

score 551 · Accepted Answer · edited Feb 27 '17 at 13:08

551

You can pass it in as part of the LinearLayout.LayoutParams constructor:

LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(
    LayoutParams.MATCH_PARENT,
    LayoutParams.MATCH_PARENT,
    1.0f
);
YOUR_VIEW.setLayoutParams(param);

The last parameter is the weight.

edited Feb 27 '17 at 13:08

David

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answered Jan 09 '11 at 19:05

Erich Douglass

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It should be `param = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT, (float) 1.0);` – Mithun Sreedharan Sep 01 '11 at 12:55
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If you don't want to cast from a double to a float just put 1.0f – Xample Jun 21 '12 at 14:58
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Or even simpler put `1f` if there are no decimal places – sandalone Aug 27 '13 at 18:48
5

what to do if parent layout is `Relative` – Pratik Butani May 13 '14 at 06:54
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@pratik if parent layout is relative you don't use weights – invertigo Oct 20 '14 at 16:01
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I think, one of two parameters LayoutParams.MATCH_PARENT should be changed to 0. – CoolMind Dec 15 '15 at 10:24
@Erich Douglass: Thanks. Working properly for me. I have used same as you mentioned above. I am using this to divide screen in 2 parts horizontally. – BK19 Oct 07 '16 at 07:18
@Erich what if i want to set 52% of weight, i have tried 0.52f, but it's not working – TapanHP Dec 29 '16 at 11:47
If all you want to do is change the weight of an existing view use parameters: view.getLayoutParams().width, view.getLayoutParams().height, – jwehrle Jun 04 '17 at 20:04

Kevin Coppock · Answer 2 · 2014-02-24T21:24:35.850

131

Use LinearLayout.LayoutParams:

LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
    LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
params.weight = 1.0f;
Button button = new Button(this);
button.setLayoutParams(params);

EDIT: Ah, Erich's answer is easier!

edited Feb 24 '14 at 21:24

answered Jan 09 '11 at 19:07

Kevin Coppock

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Erich's anser may be easier to write, but yours is easier to read. Since it says which attribute the 1.0f is used for. – Johan Apr 02 '12 at 13:28
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yours established that you can modify weight on the fly by calling 'view.getLayoutParams()' then modify the value. – RobGThai Apr 23 '13 at 07:58
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`FILL_PARENT` has been deprecated and `MATCH_PARENT` should be used instead. – Simon Forsberg Nov 01 '13 at 21:45
@SimonAndréForsberg Unfortunately many of us need to use `FILL_PARENT` still to support older versions of Android, and in the end, they both defined as the constant -1 for use in the layout. Since `MATCH_PARENT` can cause errors in older Android, in many cases it is easier to just continue to use `FILL_PARENT` – LocalPCGuy Feb 24 '14 at 21:20
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@LocalPCGuy Not true. As long as you're *targeting* SDK >= 8 (which you absolutely should be), `MATCH_PARENT` can be used instead of `FILL_PARENT` even on older devices. – Kevin Coppock Feb 24 '14 at 21:24
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@LocalPCGuy [No one uses API 7 or less anymore](http://developer.android.com/about/dashboards/index.html). If you're trying to make your app compatible with APIs 7 or less, you'd probably run into a whole lot of other problems before worrying about `FILL_PARENT` vs. `MATCH_PARENT`. – Simon Forsberg Feb 24 '14 at 21:26
Good point. I actually ran into it on an app that was originally designed to be compatible with those versions, and so had to maintain that compatibility. Guess I just never looked at exactly where the cutoff was. – LocalPCGuy Feb 24 '14 at 22:22

score 94 · Answer 3 · edited Jul 29 '16 at 17:47

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If you already define your view in your layout(xml) file, only want to change the weight programmatically, this way is better

LinearLayout.LayoutParams params = (LinearLayout.LayoutParams)   
mButton.getLayoutParams();
params.weight = 1.0f;
mButton.setLayoutParams(params);

new a LayoutParams overwrites other params defined in you xml file like margins, or you need to specify all of them in LayoutParams.

edited Jul 29 '16 at 17:47

Evin1_

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answered Jun 02 '14 at 13:50

pkliang

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With "params.weight = 1f;" you're already setting the weight on the LayoutParams object. There's no need to call "mButton.setLayoutParams(params);". – MrMaffen Mar 28 '15 at 20:32
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No, you have to call setLayoutParams – SIr Codealot Jul 10 '15 at 01:30
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This is actually the most elegant answer and it directly changes a specific UI object. The best answer is good too and older than this post. So it deserves as the best answer. I upvoted this post though. – The Original Android Jul 28 '15 at 01:51
Great and simple solution! – Jeremy Nov 25 '16 at 21:55
Works like a charm! Thanks a lot :) – Vinay Vissh Mar 01 '17 at 12:44
You don't have to call setLayoutParams. I've just tried it out. – Mitulát báti May 21 '18 at 00:14
You can actually just call `mButton.requestLayout()` instead `setLayoutParams` since you're just changing a value. `setLayoutParams` calls `requestLayout` internally. – JohnnyLambada Aug 01 '18 at 16:42

score 32 · Answer 4 · edited Mar 19 '19 at 19:51

If the constructor with width, height and weight is not working, try using the constructor with width and height. And then manually set the weight.

And if you want the width to be set according to the weight, set width as 0 in the constructor. Same applies for height. Below code works for me.

LinearLayout.LayoutParams childParam1 = new LinearLayout.LayoutParams(0,LinearLayout.LayoutParams.MATCH_PARENT);
childParam1.weight = 0.3f;
child1.setLayoutParams(childParam1);

LinearLayout.LayoutParams childParam2 = new LinearLayout.LayoutParams(0,LinearLayout.LayoutParams.MATCH_PARENT);
childParam2.weight = 0.7f;
child2.setLayoutParams(childParam2);

parent.setWeightSum(1f);
parent.addView(child1);
parent.addView(child2);

Just what I needed! Every one is talking about setting weights here, no one displayed what happens when those weighed Children are added to the Parent View! I was actually looking for how to add weightSum on the ParentView! Thanks! — sud007, Mar 17 '16 at 07:12

score 19 · Answer 5 · answered Mar 26 '18 at 06:03

19

If layoutparams is already defined (in XML or dynamically), Here's a one liner:

((LinearLayout.LayoutParams) mView.getLayoutParams()).weight = 1;

answered Mar 26 '18 at 06:03

Desolator

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Underrated answer – Adam Higgins Jan 21 '20 at 12:09

score 15 · Answer 6 · answered Nov 20 '14 at 13:14

15

If I someone looking for answer, use this:

LinearLayout.LayoutParams lay = (LinearLayout.LayoutParams) myLayout.getLayoutParams();
lay.weight = 0.5;

If you are initializing your layout from xml file, this will be much more convenient than providing new layout parameters for Linear Layout.

answered Nov 20 '14 at 13:14

Coder

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This should be the accepted answer as it doesn't modify any previously set variables like width/height/margin/padding etc. Everything is being kept and re-used while the weight is changed. – MrMaffen Mar 28 '15 at 20:34
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If the view to set `layout_weight` has already been laid out, you need to call `View.requestLayout()` to update. – Attacktive Sep 21 '15 at 06:03

score 8 · Answer 7 · edited Feb 24 '14 at 22:25

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Any of LinearLayout.LayoutParams and TableLayout.LayoutParams worked for me, for buttons the right one is TableRow.LayoutParams. That is:

            TableRow.LayoutParams buttonParams = new TableRow.LayoutParams(
                    TableRow.LayoutParams.MATCH_PARENT,
                    TableRow.LayoutParams.WRAP_CONTENT, 1f);

About using MATCH_PARENT or WRAP_CONTENT be the same.

edited Feb 24 '14 at 22:25

LocalPCGuy

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answered Dec 18 '12 at 23:41

Andres Felipe

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`FILL_PARENT` has been deprecated and `MATCH_PARENT` should be used instead. – Simon Forsberg Nov 01 '13 at 21:44
I think LayoutParams.MATCH_PARENT should be changed to 0. – CoolMind Dec 15 '15 at 10:25
You call the `LayoutParams` of the direct parent. I assume you had a crash attempting to use `LinearLayout.LayoutParams` without the parent `LinearLayout`. – Abandoned Cart Feb 24 '20 at 05:03

score 4 · Answer 8 · answered Jun 24 '16 at 10:43

If you have already defined your view in layout(xml) file and only want to change the weight pro grammatically, then then creating new LayoutParams overwrites other params defined in you xml file.

So first you should use "getLayoutParams" and then setLayoutParams

LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) mButton.getLayoutParams(); params.weight = 4f; mButton.setLayoutParams(params);

score 3 · Answer 9 · answered Nov 06 '21 at 07:03

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I have done my task by adding this line of code!

LinearLayout.LayoutParams mylayout = (LinearLayout.LayoutParams)   
myview.getLayoutParams();
mylayout.weight = 2;
myview.setLayoutParams(mylayout);

answered Nov 06 '21 at 07:03

Ali Raza Khan

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score 0 · Answer 10 · answered Apr 20 '18 at 19:03

Using Kotlin you can do something like:

import android.content.Context
import android.support.v4.content.ContextCompat
import android.support.v7.widget.CardView
import android.widget.*

import android.widget.LinearLayout

class RespondTo : CardView {
    constructor(context: Context) : super(context) {
        init(context)
    }

    private fun init(context: Context) {


        val parent = LinearLayout(context)

        parent.apply {
            layoutParams = LinearLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT,
                    FrameLayout.LayoutParams.WRAP_CONTENT, 1.0f).apply {
                orientation = LinearLayout.HORIZONTAL

                addView(EditText(context).apply {
                    id = generateViewId()
                    layoutParams = LinearLayout.LayoutParams(0,
                            LinearLayout.LayoutParams.WRAP_CONTENT, 0.9f).apply {
                    }
                })
                addView(ImageButton(context).apply({
                    layoutParams = LinearLayout.LayoutParams(0,
                            LinearLayout.LayoutParams.WRAP_CONTENT, 0.1f)
                    background = null
                    setImageDrawable(ContextCompat.getDrawable(context, R.drawable.ic_save_black_24px))
                    id = generateViewId()
                    layoutParams = RelativeLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,
                            LinearLayout.LayoutParams.WRAP_CONTENT).apply {
                        addRule(RelativeLayout.ALIGN_PARENT_RIGHT)
                        // addRule(RelativeLayout.LEFT_OF, myImageButton.id)
                    }
                }))
            }
        }
        this.addView(parent)
    }
}

score 0 · Answer 11 · answered Jan 02 '23 at 07:44

if you want to set weight to LinearLayout then use code mentioned below or set weight to Relative Layout then replace it with Relative Layout

LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(
LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT,
1.0f

); YOUR_VIEW.setLayoutParams(param);

score 0 · Answer 12 · answered Jan 04 '23 at 19:50

You can try this approach. First, you get the LayoutParams associated with this Button. Perform a type conversion.

LinearLayout.LayoutParams linearLayoutParams = (LinearLayout.LayoutParams) button.getLayoutParams();

Then assign the required value of the "weight" parameter.

linearLayoutParams.weight = 5;

Redraw the layout.

button.requestLayout();

score 0 · Answer 13 · answered Mar 17 '23 at 16:21

0

This is how you do it in Kotlin:

val params = mButton.layoutParams as LinearLayout.LayoutParams
params.weight = 1.0f
mButton.layoutParams = params

answered Mar 17 '23 at 16:21

Houman

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How to set layout_weight attribute dynamically from code?

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