问题
How can I set the value for the attribute layout_weight
for button in android dynamically from java code ?
回答1:
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.
回答2:
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!
回答3:
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.
回答4:
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);
回答5:
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.
回答6:
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.
回答7:
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);
回答8:
If layoutparams
is already defined (in XML or dynamically), Here's a one liner:
((LinearLayout.LayoutParams) mView.getLayoutParams()).weight = 1;
回答9:
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)
}
}
来源:https://stackoverflow.com/questions/4641072/how-to-set-layout-weight-attribute-dynamically-from-code