Develop Reference

Issue with layout weight in Android LinearLayout

The way my program works is that I take user input for 3 items, create a horizontal LinearLayout programmatically with those three items. Then place that LinearLayout inside a RelativeLayout that is defined in XML.
User can keep adding these 3-item horizontal LLs to the bottom of the RelativeLayout, which acts as a list in this case.
I am specifying a weight in the setLayoutParams method for each TextView object
TextView quantityText = new TextView(MainActivity.this);
quantityText.setLayoutParams(new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT, 1f));
quantityText.setText("" + currentIngredientMeasurementQuantity);
TextView typeText = new TextView(MainActivity.this);
typeText.setLayoutParams(new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT, 1f));
typeText.setText(currentIngredientMeasurementType);
TextView nameText = new TextView(MainActivity.this);
nameText.setLayoutParams(new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT, 4f));
nameText.setText(currentIngredientName);
LinearLayout ll = new LinearLayout(MainActivity.this);
ll.setId(View.generateViewId());
RelativeLayout relativeLayout = (RelativeLayout) findViewById(R.id.ingredient_list_relativelayout);
RelativeLayout.LayoutParams relativeParams = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
//Find last member of RelativeLayout
View lastIngredient = (View) relativeLayout.getChildAt(totalIngredientQuantity - 1);
relativeParams.addRule(RelativeLayout.BELOW, lastIngredient.getId());
relativeParams.setMargins(0, 0, 0, 0);
ll.addView(quantityText);
ll.addView(typeText);
ll.addView(nameText);
relativeLayout.addView(ll, relativeParams);
The problem is, the TextViews aren't being displayed the way I'd like them to. I'd like each of the three items to line up vertically, like a proper list.
Instead, I get something like this. You can see that the length of the strings is somehow affecting the way the layout is stored/displayed.
I know it's a big block of code, but any help would be appreciated!

Try this:-
Create a custom layout insteadof creating controls as dynamically
custom.xml
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="90">
<TextView
android:id="#+id/textview1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="30"
android:gravity="center"
android:text="text1"/>
<TextView
android:id="#+id/textview2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:gravity="center"
android:layout_weight="30"
android:text="text2"/>
<TextView
android:id="#+id/textview3"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:gravity="center"
android:layout_weight="30"
android:text="text3"/>
</LinearLayout>
Add this view in RelativeLayout
View view = factory.inflate(R.layout.custom, null);
relativeLayout.addView(view);

You need to set the layout_width property to 0 for layout weight property to work well. I made a couple to changes to your code to make it work well for me.
Try this,
private void addNewRow(float currentIngredientMeasurementQuantity, String currentIngredientMeasurementType, String currentIngredientName) {
TextView quantityText = new TextView(MainActivity.this);
quantityText.setLayoutParams(new LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.WRAP_CONTENT, 1f));
quantityText.setText("" + currentIngredientMeasurementQuantity);
TextView typeText = new TextView(MainActivity.this);
typeText.setLayoutParams(new LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.WRAP_CONTENT, 1f));
typeText.setText(currentIngredientMeasurementType);
TextView nameText = new TextView(MainActivity.this);
nameText.setLayoutParams(new LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.WRAP_CONTENT, 4f));
nameText.setText(currentIngredientName);
LinearLayout ll = new LinearLayout(MainActivity.this);
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN) {
ll.setId(View.generateViewId());
} else {
ll.setId(totalIngredientQuantity);
}
RelativeLayout relativeLayout = (RelativeLayout) findViewById(R.id.ingredient_list_relativelayout);
RelativeLayout.LayoutParams relativeParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
//Find last member of RelativeLayout
View lastIngredient = (View) relativeLayout.getChildAt(totalIngredientQuantity - 1);
if (lastIngredient != null) {
relativeParams.addRule(RelativeLayout.BELOW, lastIngredient.getId());
relativeParams.setMargins(0, 0, 0, 0);
}
ll.addView(quantityText);
ll.addView(typeText);
ll.addView(nameText);
relativeLayout.addView(ll, relativeParams);
}

You have to set the Gravity to Left (or Start) on your TextViews before adding them to the LinearLayout, just like this:
LinearLayout.LayoutParams name_lp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT
);
name_lp.gravity = Gravity.LEFT;
nameText.setLayoutParams(name_lp);

Try to tell your your Textviews to use all the available space they can get. So they will fill the whole LinearLayout.
Instead of WRAP_CONTENT use MATCH_PARENT or FILL_PARENT
In XML you could use 0dip like described here: In android layouts what is the effect/meaning of layout_height="0dip"
Another idea would be to use TableLayout or GridLayout http://developer.android.com/reference/android/widget/GridLayout.html
http://developer.android.com/reference/android/widget/TableLayout.html
Have Fun

Adding a view between 2 views when one view is aligned to the bottom programmatically

I have a relative layout that contains a scrollview that I want to place between 2 other relative layouts. One of these layouts is aligned to parent bottom. I would like for it to stay at the bottom.
Here's my code:
RelativeLayout.LayoutParams formRenderParams = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
mainLayout.setLayoutParams(formRenderParams);
formRenderParams.addRule(RelativeLayout.BELOW, pageButtons.getId());
//relative is the relative layout that has been aligned to bottom in previous code
RelativeLayout.LayoutParams p = (RelativeLayout.LayoutParams) relative.getLayoutParams();
p.addRule(RelativeLayout.BELOW, r_scroll.getId());
relative.setLayoutParams(p);
mainLayout.addView(r_scroll, formRenderParams);
pageButtons is Layout A, r_scroll is Layout B, and relative is Layout C.
The problem is that C disappears. It either disappears with this code, or B overlaps it. What I want is for B to take up the remaining space, but with no overlapping.
Also here's a picture to show the problem visually:
Any ideas on what's going on? Any help would be appreciated. Thank you.

Try this
RelativeLayout rlmain= (RelativeLayout) findViewById(R.id.rlMain);
RelativeLayout rA=new RelativeLayout(MainActivity.this);
RelativeLayout.LayoutParams layoutA = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
rA.setId(1);
rA.setBackgroundColor(getResources().getColor(R.color.blue));
layoutA.addRule(RelativeLayout.ALIGN_PARENT_TOP, rlmain.getId());
rA.setLayoutParams(layoutA);
TextView tvA=new TextView(MainActivity.this);
RelativeLayout.LayoutParams tvParamA = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
tvA.setText("This is Layout 1");
tvA.setLayoutParams(tvParamA);
rA.addView(tvA);
RelativeLayout rC=new RelativeLayout(MainActivity.this);
RelativeLayout.LayoutParams layoutC = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
layoutC.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM,rlmain.getId());
rC.setId(3);
rC.setLayoutParams(layoutC);
rC.setBackgroundColor(getResources().getColor(R.color.gray));
TextView tvC=new TextView(MainActivity.this);
RelativeLayout.LayoutParams tvParamC = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
tvC.setText("This is Layout 3");
tvC.setLayoutParams(tvParamC);
rC.addView(tvC);
RelativeLayout rB=new RelativeLayout(MainActivity.this);
RelativeLayout.LayoutParams layoutB = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
layoutB.addRule(RelativeLayout.BELOW, rA.getId());
layoutB.addRule(RelativeLayout.ABOVE, rC.getId());
rB.setId(2);
rB.setLayoutParams(layoutB);
rB.setBackgroundColor(getResources().getColor(R.color.orange));
ScrollView scroll=new ScrollView(MainActivity.this);
RelativeLayout.LayoutParams scrollB = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
scroll.setLayoutParams(scrollB);
rB.addView(scroll);
rlmain.addView(rA);
rlmain.addView(rB);
rlmain.addView(rC);
rlMain in above code is the RelativeLayout declared in xml file.
Hope this may help you!

just follow the pattern of this layout
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:id="#+id/a"
android:layout_alignParentTop="true"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<RelativeLayout
android:id="#+id/b"
android:layout_below="#+id/a"
android:layout_above="#+id/c"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
</ScrollView>
</RelativeLayout>
<RelativeLayout
android:id="#+id/c"
android:layout_alignParentBottom="true"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</RelativeLayout>

Just add to RelativeLayout.LayoutParams of formRenderParams this rule:
formRenderParams.addRule(RelativeLayout.ABOVE, relative .getId());
and change
p.addRule(RelativeLayout.BELOW, r_scroll.getId());
to
p.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
to avoid circular dependencies in layout.
Edit
RelativeLayout.LayoutParams formRenderParams = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
r_scroll.setBackgroundColor(getResources().getColor(android.R.color.black)); // this is just to test the guess

Android LinearLayout in ScrollView

I tryning to get a LinearLayout in a ScrollView like this:
The greenspace should be wrap_content and the red one should take the remaining space.
But this is my Result:
This is my Code:
foreach(Ele el : elements) {}
LinearLayout layout = new LinearLayout(getActivity());
LayoutParams layout_parm = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
layout.setOrientation(LinearLayout.HORIZONTAL);
layout.setLayoutParams(layout_parm);
TextView tv = new TextView(getActivity());
tv.setLayoutParams( new LayoutParams(0, LayoutParams.WRAP_CONTENT, 1) );
tv.setBackgroundColor(getActivity().getResources().getColor((R.color.red)));
tv.setTextSize(TypedValue.COMPLEX_UNIT_SP, 16);
tv.setText("Name...");
tv.setPadding(0, 0, 0, getDP(5));
layout.addView(tv);
TextView iView = new TextView(getActivity());
iView.setText("OTO");
iView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 16);
iView.setBackgroundColor(getActivity().getResources().getColor((R.color.green)));
iView.setLayoutParams( new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, 0) );
layout.addView(iView);
frg_layout.addView(layout);
}
I am so confused! Maybe you can help me to find out my fail...
Thank you!
The Parent-ViewGroup:
<LinearLayout
android:id="#+id/frg_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top"
android:gravity="top"
android:orientation="vertical" />

you change the layout orientation
LinearLayout layout = new LinearLayout(getActivity());
LayoutParams layout_parm = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
layout.setOrientation(LinearLayout.VERTICAL);
layout.setLayoutParams(layout_parm);
uset this type in xml
<LinearLayout
android:id="#+id/frg_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/TextView1"
android:layout_width="250dp"
android:layout_height="60dp"/>
<TextView
android:id="#+id/textview2"
android:layout_width="250dp"
android:layout_height="60dp"
/>
</linearlayout>

I think you've mostly got it right, just need a few minor tweaks:
for each(Ele el:elements){
LinearLayout layout = new LinearLayout(getActivity());
LayoutParams layout_parm = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
layout.setOrientation(LinearLayout.HORIZONTAL);
layout.setLayoutParams(layout_parm);
TextView tv = new TextView(getActivity());
//adjust the last number here to make the first block wider or larger as you want
tv.setLayoutParams(new LayoutParams(0, LayoutParams.WRAP_CONTENT, 2));
tv.setBackgroundColor(getActivity().getResources().getColor((R.color.red)));
tv.setTextSize(TypedValue.COMPLEX_UNIT_SP, 16);
tv.setText("Name...");
tv.setPadding(0, 0, 0, getDP(5));
layout.addView(tv);
TextView iView = new TextView(getActivity());
iView.setText("OTO");
iView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 16);
iView.setBackgroundColor(getActivity().getResources().getColor((R.color.green)));
//adjust your layout param to be a weight instead of wrap_content
iView.setLayoutParams(new LayoutParams(0, LayoutParams.WRAP_CONTENT, 1));
layout.addView(iView);
frg_layout.addView(layout);
}
See if that works! An alternative would be to build an xml layout which I think is generally cleaner, but programatically it should work roughly the same way.

Using LayoutInflater with xml will bring the solutuion!
Thank you!

How to create Hierarchical RelativeLayouts programmatically in android?

I am new in android and I have done so much googling for this issue. Actually I want to create below UI in Code of android:
<RelativeLayout
android:id="#+id/relativeLayout2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:background="#drawable/tab_background">
<RelativeLayout
android:id="#+id/event_1"
android:layout_width="40dp"
android:layout_height="40dp"
android:background="#drawable/color_001">
<TextView
android:id="#+id/txt_event_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:layout_margin="1dp"
android:gravity="center"
android:text="j1"
android:textStyle="bold"
android:textColor="#ffffff" />
</RelativeLayout>
</RelativeLayout>
Can anybody help me, please?

I have written a quick example code based on your xml layout. I tried make it clear by using comments but if you don't understand something, I can try to explain it a little more.
// Creating the outer RelativeLayout which has id "relativeLayout2" in your xml layout.
RelativeLayout outerRelativeLayout = new RelativeLayout(context);
// ------------------------------------------------------------------
// Creating the inner RelativeLayout which has id "event_1" in your xml layout.
RelativeLayout innerRelativeLayout = new RelativeLayout(context);
// Creating the TextView which has id "txt_event_1" in your xml layout.
TextView textView = new TextView(context);
textView.setGravity(Gravity.CENTER);
textView.setText("j1");
// Defining the layout parameters of the TextView
RelativeLayout.LayoutParams textViewParams = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
textViewParams.addRule(RelativeLayout.CENTER_HORIZONTAL, RelativeLayout.TRUE);
textViewParams.addRule(RelativeLayout.CENTER_VERTICAL, RelativeLayout.TRUE);
// Adding the TextView to the inner RelativeLayout as a child
innerRelativeLayout.addView(textView, new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
// ------------------------------------------------------------------
// Adding the inner RelativeLayout to the outer RelativeLayout as a child
outerRelativeLayout.addView(innerRelativeLayout, new RelativeLayout.LayoutParams(convertDptoPx(40), convertDptoPx(40)));
// ------------------------------------------------------------------
// Defining the layout parameters of the outer RelativeLayout
RelativeLayout.LayoutParams rootParams = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
rootParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, RelativeLayout.TRUE);
// Set the layout parameters associated with the outer RelativeLayout.
outerRelativeLayout.setLayoutParams(rootParams);
Although this code snippet doesn't include some of the xml attributes defined in your xml layout, you can find the related methods in the documentation of the view.
For instance, if you look at the TextView documentation (http://developer.android.com/reference/android/widget/TextView.html), you can see the "XML Attributes" table which shows the attribute name and related method.

use this code.
RelativeLayout layout1= new RelativeLayout(this);
LayoutParams param1= new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT);
RelativeLayout layout2= new RelativeLayout(this);
LayoutParams param2= new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
TextView text= new TextView(this);
text.setText("your text");
layout2.addView(text, param2);
layout1.addView(layout2, param1);
setContentView(layout1);

RelativeLayout.LayoutParams childVw = new RelativeLayout.LayoutParams(40, 40);
TextView textVw = new TextView(this);
textVw.setLayoutParams(childVw);
Then add this to your main relative layout

setContentView(R.layout.layoutfilename);
RelativeLayout layout1= (RelativeLayout)findViewById(R.id.yourlayoutid);
LayoutParams param1= new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT);
RelativeLayout layout2= new RelativeLayout(this);
LayoutParams param2= new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
TextView text= new TextView(this);
text.setText("your text");
layout2.addView(text, param2);
layout1.addView(layout2);

android Layout weight programmatically

i have hard-coded the layout_weight on layout xml.but now i want to give the layout_weight and weightSum from java code.
How we do that from our class?
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="25" >
<TextView
android:id="#+id/textView1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="5"
android:background="#F51215"
android:paddingLeft="5dip"
android:text="5" />
<TextView
android:id="#+id/textView2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="20"
android:background="#1AC92B"
android:paddingLeft="5dip"
android:text="20" />
</LinearLayout>

Something like this:
......
LinearLayout layout = (LinearLayout)findViewById(YOUR_LAYOT_ID);
layout.setWeightSum(25f);
LinearLayout.LayoutParams lParams = (LinearLayout.LayoutParams) layout.getLayoutParams(); //or create new LayoutParams...
lParams.weight = 0.5f;
.......
someView.setLayoutParams(lParams);
.......

//set as like this below for different view set different float value.
myview.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT,5f));

I just wanted to add an example of how to use the weightsum with e.g a TableRow with TextViews inside:
TableRow row = new TableRow(this);
TableRow.LayoutParams params1 = new TableRow.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT, 10f);
row.setLayoutParams(params1);
row.setPadding(10, 10, 10, 10);
row.setBackgroundColor(R.color.black);
TextView tv = new TextView(this);
TableRow.LayoutParams params2 = new TableRow.LayoutParams(0, LayoutParams.WRAP_CONTENT, 6f);
tv.setLayoutParams(params2);
tv.setTextSize(30);
tv.setBackgroundResource(R.color.white);
TextView tv2 = new TextView(this);
TableRow.LayoutParams params3 = new TableRow.LayoutParams(0, LayoutParams.MATCH_PARENT, 2f);
tv2.setLayoutParams(params3);
tv2.setBackgroundResource(R.color.green);
TextView tv3 = new TextView(this);
TableRow.LayoutParams params4 = new TableRow.LayoutParams(0, LayoutParams.MATCH_PARENT, 2f);
tv3.setLayoutParams(params4);
tv3.setBackgroundResource(R.color.blue);
Produces the TableRow underneath. The parent whose weightsum is 10, and the children's widths are then equal to 60%, 20% and 20% of the width. The height is here determined by the TextView, tv, which has a height of 30. Hope it helps someone. :-)

If You want to change parent weight programmatically and it's child property as it is then use below
Here's how you set it.
LinearLayout yourLayout=(LinearLayout)findViewById(R.id.container);
yourLayout.setWeightSum(0.6f);

Dynamically Generate TextView with Weight using LinearLayout
LinearLayout lin_hoizontal = new LinearLayout(context);
lin_hoizontal.setOrientation(LinearLayout.HORIZONTAL);
lin_hoizontal.setLayoutParams(new android.widget.LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT, 10f));
lin_hoizontal.setPadding((int) context.getResources().getDimension(R.dimen.d_8), (int) context.getResources().getDimension(R.dimen.d_2), (int) context.getResources().getDimension(R.dimen.d_8), (int) context.getResources().getDimension(R.dimen.d_2));
android.widget.LinearLayout.LayoutParams params_label = new android.widget.LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.WRAP_CONTENT, 2.5f);
TextView txt_label = new TextView(context);
txt_label.setTextColor(context.getResources().getColor(R.color.listing_header_txt_color));//your text color
txt_label.setTextSize(TypedValue.COMPLEX_UNIT_PX, context.getResources().getDimension(R.dimen.d_13));
txt_label.setTypeface(Typeface.create("sans-serif-medium", Typeface.NORMAL));
txt_label.setLayoutParams(params_label);
txt_label.setPadding(0, 0, (int) context.getResources().getDimension(R.dimen.d_2), 0);
txt_label.setText("Label");
android.widget.LinearLayout.LayoutParams params_value = new android.widget.LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.WRAP_CONTENT, 7.5f);
TextView txt_value = new TextView(context);
txt_value.setTextColor(context.getResources().getColor(R.color.listing_header_txt_color));
txt_value.setTextSize(TypedValue.COMPLEX_UNIT_PX, context.getResources().getDimension(R.dimen.d_13));
txt_value.setTypeface(Typeface.create("sans-serif-light", Typeface.NORMAL));
txt_value.setLayoutParams(params_value);
txt_value.setPadding((int) context.getResources().getDimension(R.dimen.d_2), 0, 0, 0);
txt_value.setText("Value");
lin_hoizontal.addView(txt_label);
lin_hoizontal.addView(txt_value);
lin_hoizontal.addView(lin_main);

I like Ajii's answer or:
((LinearLayout)view).setWeightSum(n);
and for individual view weight:
((LinearLayout.LayoutParams)view.getLayoutParams()).weight = n;
of course you can do.. LinearLayout view = findViewById(R.id.view_name);
(and drop the dynamic casting (LinearLayout))
or substitute...……….. findViewById(R.id.view_name) for view above.
These both worked for me.
And if you want value in dimens file:
<item name="new_weight" format="float" type="dimen">(your number)</item>
and: float n = getResources().getFloat(R.dimen.new_weight);
I'm sure you already know most of this but... I was a newbie once and I always appreciated the extra descriptions.