Button被选择之后，背景颜色的变化

int mstate=-1;

@Override
public void onClick(View v) {
    switch (v.getId()){
        case R.id.btn01_dengji:
                switchState(0);
                FragmentUtil.replaceFragment(manager,new DengJiFragment(),R.id.framelayout01);
            break;
        case R.id.btn01_caiji:
            switchState(1);
            FragmentUtil.replaceFragment(manager,new CaijiFragment(),R.id.framelayout01);
            break;
        case R.id.btn01_jianji:
            switchState(2);
            FragmentUtil.replaceFragment(manager,new JianJiFragment(),R.id.framelayout01);
            break;
        case R.id.btn01_zhenduan:
            switchState(3);
            FragmentUtil.replaceFragment(manager,new ZhenDuanFragment(),R.id.framelayout01);
            break;

        case R.id.btn_right:
                  getPopupMenu(this,btn_rigth);

            break;

        default:break;

    }

}

 //判断选择了哪个按钮     private void switchState(int state){        if (mstate==state){  //如果重复点击当前的按钮，那么界面就不需要变化了            Toast.makeText(this, "不需要重新重建Fragment", Toast.LENGTH_SHORT).show();            return;        }        mstate=state;        btn_dengji.setSelected(false);        btn_caiji.setSelected(false);        btn_jianji.setSelected(false);        btn_zhenduan.setSelected(false);//        Object tag=null;        switch (mstate){            case 0:                btn_dengji.setSelected(true);//                tag=mStateButton1.getTag();                break;            case 1:                btn_caiji.setSelected(true);//                tag=mStateButton1.getTag();                break;            case 2:                btn_jianji.setSelected(true);//                tag=mStateButton1.getTag();                break;            case 3:                btn_zhenduan.setSelected(true);//                tag=mStateButton1.getTag();                break;            default:                break;        }

//按钮选择之后，背景的颜色的变化 text_server_select.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true" android:drawable="@color/main_color"></item>
<item android:state_selected="true" android:drawable="@color/main_color"></item>

</selector>