Android 修改AlertDialog原生setPositiveButton的字体颜色背景颜色大小边距位置

 看效果图：

  public void lanyaClick(View v) {
        //点击确定之后转向登陆框
        LayoutInflater factory = LayoutInflater.from(Beforestart.this);
        //得到自定义对话框
        final View DialogView = factory.inflate(R.layout.item_alert_dialog, null);
        //创建对话框
        android.app.AlertDialog dlg = new AlertDialog.Builder(Beforestart.this)
                .setTitle("")
                .setView(DialogView)
                .setPositiveButton("登录", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int whichButton) {
                            Button Button1 = (Button) findViewById(R.id.blechongdian);
                            //添加按钮点击事件的监听器
                            Button1.setOnClickListener(new View.OnClickListener() {
                                @Override
                                public void onClick(View view) {
                                    binder.setData("Loginpassword", 
                                    //实现界面跳转
                                    Intent intent = new Intent();
                                    intent.setClass(Beforestart.this, BluetoothCharging.class);
                                    startActivity(intent);
                                }
                            });
                    }
                  }).create();
        dlg.getWindow().setBackgroundDrawableResource(R.drawable.yuanjiao5); //设置对话框的样式
        dlg.show();
        Button button = dlg.getButton(AlertDialog.BUTTON_POSITIVE);
        LinearLayout.LayoutParams cancelBtnPara = (LinearLayout.LayoutParams) button.getLayoutParams();
        //设置按钮的大小
        cancelBtnPara.height = LinearLayout.LayoutParams.WRAP_CONTENT;
        cancelBtnPara.width = LinearLayout.LayoutParams.MATCH_PARENT;
        //设置文字居中
        cancelBtnPara.gravity = Gravity.CENTER;
        //设置按钮左上右下的距离
        cancelBtnPara.setMargins(100, 50, 100, 30);
        button.setLayoutParams(cancelBtnPara);
        button.setBackground(ContextCompat.getDrawable(this, R.drawable.bg_yuanjiao));
        button.setTextColor(ContextCompat.getColor(this, R.color.white));
        button.setTextSize(16);
    }

 主要的代码是show下面的：