relativelayout.layoutparams not being applied to view

[john bean]

cant figure why these params are not being applied buttonp works and the view is in the right place but letp dont seem to do anything the view is small and placed i the top left of the screen not the center and stretched to matchparent cant figure it out anyway here is the code any help would be great thanks..

 protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        rel=new RelativeLayout(this);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
        Resources res = getResources();

        //return button#####################################
        RelativeLayout.LayoutParams buttonp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
        buttonp.addRule(RelativeLayout.ALIGN_PARENT_TOP);
        buttonp.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
        Button returnbut=new Button(this);
        Drawable drawablemenu = res.getDrawable(R.drawable.backicon);
        returnbut.setBackground(drawablemenu);
        returnbut.setLayoutParams(buttonp);//this works fine
        returnbut.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent myIntent = new Intent(Letter.this, MainActivity.class);
                Letter.this.startActivity(myIntent);
            }
        });
        //###################################################


        TextView let=new TextView(this);
        let.setText(lether);
        let.setTextColor(Color.BLACK);
        RelativeLayout.LayoutParams letP = new RelativeLayout.LayoutParams
                (RelativeLayout.LayoutParams.FILL_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
        letP.addRule(RelativeLayout.CENTER_IN_PARENT);

        let.setLayoutParams(letP);//this seems to do nothing the text is small and in top left of relativelayout

        rel.addView(let);
        rel.addView(returnbut);
        setContentView(rel);

[Giovanni Montano]

why are you pinpointing your button with this?

Button returnbut=new Button(this);

It is not java, if you pass this will be called I am afraid an instance of the Activity!
you need to refer your button with  

findViewById(R.id.NameOfYourButton)

this is how android coders do, also notice that in real life you will see this referenced by mean of  a library called Butterknife