android - setting LayoutParams programmatically

Question

I putting an in-game chat module into an app. I am adding text messages as they are received into a LinearLayout view. I want to set the layout params to the TextView but the following code is crashing and the error messages befuddle me.

private void addChat(String chat, String when,  Boolean mine) {
    int leftMargin;

    TextView tv = new TextView(this);
    llview.addView(tv);
    tv.setTextColor(Color.WHITE);
    tv.setTextSize(2,25);
    tv.setText(chat);
    if (mine) {
        leftMargin = 5;
        tv.setBackgroundColor(0x7C5B77);
    }
    else {
        leftMargin = 50;
        tv.setBackgroundColor(0x778F6E);
    }
    final ViewGroup.MarginLayoutParams lpt =(MarginLayoutParams)tv.getLayoutParams();
    lpt.setMargins(leftMargin,lpt.topMargin,lpt.rightMargin,lpt.bottomMargin);

    tv.setLayoutParams(new ViewGroup.LayoutParams(
            ViewGroup.LayoutParams.WRAP_CONTENT,
            ViewGroup.LayoutParams.WRAP_CONTENT));

}

when it runs, all of the above code executes but it crashes in android runtime as:

03-13 14:15:38.513: E/AndroidRuntime(12985): java.lang.ClassCastException:      android.view.ViewGroup$LayoutParams

and stepping through with the debugger, it actually processes all of these lines

but then barfs when trying to render with an equally cryptic exception detailed message:

android.view.ViewGroup$LayoutParams

So, what have done to get to this state? What should I be doing to have alternating left/right indented messages ?

score 135 · Accepted Answer · edited Oct 13 '15 at 11:49

135

Just replace from bottom and add this

tv.setLayoutParams(new ViewGroup.LayoutParams(
    ViewGroup.LayoutParams.WRAP_CONTENT,
    ViewGroup.LayoutParams.WRAP_CONTENT));

before

llview.addView(tv);

edited Oct 13 '15 at 11:49

Ziem

6,351
7
51
85

answered Mar 13 '12 at 05:50

Khan

7,545
3
26
43

1

How to setLayoutParams in `dp` values rather than `wrap_content` or `match_parent`. I want to set it to `100dp` each. – Sagar Balyan Aug 28 '17 at 06:56
I have exactly the same question and can't find the solution. – Prabhakar Feb 18 '18 at 16:10
@SagarBalyan see https://stackoverflow.com/a/58154612/11675817 – M Karimi Nov 09 '19 at 09:15
@Prabhakar look at this: https://stackoverflow.com/a/58154612/11675817 – M Karimi Nov 09 '19 at 09:15
/*in DP */ ViewGroup.LayoutParams prm = new ViewGroup.LayoutParams( ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT); prm.height=200; prm.width=200; pieChart.setLayoutParams(prm); – garish Nov 03 '20 at 10:16
Why are we using `ViewGroup` for `TextView`? – Rawnak Yazdani Oct 02 '21 at 18:17

score 32 · Answer 2 · answered Mar 13 '12 at 05:40

32

after creating the view we have to add layout parameters .

change like this

TextView tv = new TextView(this);
tv.setLayoutParams(new ViewGroup.LayoutParams(
        ViewGroup.LayoutParams.WRAP_CONTENT,
        ViewGroup.LayoutParams.WRAP_CONTENT));

llview.addView(tv);
tv.setTextColor(Color.WHITE);
tv.setTextSize(2,25);
tv.setText(chat);
if (mine) {
    leftMargin = 5;
    tv.setBackgroundColor(0x7C5B77);
}
else {
    leftMargin = 50;
    tv.setBackgroundColor(0x778F6E);
}
final ViewGroup.MarginLayoutParams lpt =(MarginLayoutParams)tv.getLayoutParams();
lpt.setMargins(leftMargin,lpt.topMargin,lpt.rightMargin,lpt.bottomMargin);

answered Mar 13 '12 at 05:40

RajaReddy PolamReddy

22,160
18
112
166

5

`lpt.setMargins(..)` does not seem to have any effect. Whether i set it to 2 or 20, it looks exactly the same. I see no space created for the margins at all. I tried it for a `LinearLayout`, not `TextView`. – faizal Nov 09 '14 at 06:38
4

^ tv.setLayoutParams(lpt) after the lpt.setMargins() request – worked Mar 30 '16 at 13:04
How to setLayoutParams in `dp` values rather than `wrap_content` or `match_parent`. I want to set it to `100dp` each. – Sagar Balyan Aug 28 '17 at 06:56
You can try like this : float width = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, {widthInDp}, r.getDisplayMetrics()); float height = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, {heightInDp}, r.getDisplayMetrics()); mChart.setLayoutParams(new ViewGroup.LayoutParams( width, height)); – RajaReddy PolamReddy Aug 29 '17 at 06:29
Pretty sure that cast will throw an exception – Barry Fruitman Oct 31 '21 at 22:40

M Karimi · Answer 3 · 2019-11-09T09:10:29.027

5

int dp1 = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 1,
            context.getResources().getDisplayMetrics());

tv.setLayoutParams(new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
dp1 * 100)); // if you want to set layout height to 100dp

llview.addView(tv);

edited Nov 09 '19 at 09:10

answered Sep 29 '19 at 11:08

M Karimi

927
7
19

score 4 · Answer 4 · answered Jan 22 '18 at 11:16

4

  LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(
                   /*width*/ ViewGroup.LayoutParams.MATCH_PARENT,
                   /*height*/ ViewGroup.LayoutParams.MATCH_PARENT,
                   /*weight*/ 1.0f
            );
            YOUR_VIEW.setLayoutParams(param);

answered Jan 22 '18 at 11:16

Kapil Parmar

816
7
18

Why did you use `LinearLayout` and `ViewGroup`? – Rawnak Yazdani Oct 02 '21 at 18:18

score 0 · Answer 5 · answered Jul 29 '20 at 04:48

For Xamarin Android align to the left of an object

int dp24 = (int)TypedValue.ApplyDimension( ComplexUnitType.Dip, 24, Resources.System.DisplayMetrics );
            RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams( dp24, dp24 );
            lp.AddRule( LayoutRules.CenterInParent, 1 );
            lp.AddRule( LayoutRules.LeftOf, //Id of the field Eg m_Button.Id ); 
            m_Button.LayoutParameters = lp;

android - setting LayoutParams programmatically

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