Question

How to change the button text color and button shape(rectangle) dynamically/programmatically?

Answer 1

If you have a button in your main.xml with id=button1 then you can use it as follows:

setContentView(R.layout.main);

Button mButton=(Button)findViewById(R.id.button1);
mButton.setTextColor(Color.parseColor("#FF0000")); // custom color
//mButton.setTextColor(Color.RED); // use default color
mButton.setBackgroundResource(R.drawable.button_shape);

R.drawable.button_shape(button_shape.xml):

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
  <gradient
      android:startColor="#70ffffff"
      android:centerColor="#70ffffff"
      android:endColor="#70ffffff"
      android:angle="270" />
  <corners 
        android:bottomRightRadius="8dp"
        android:bottomLeftRadius="8dp"
        android:topLeftRadius="8dp"
        android:topRightRadius="8dp"/>  
</shape>

You can have your own shape file.change it according to your need.