android 使用代码实现 RelativeLayout布局

只需把代码copy进入oncreate方法即可运行

RelativeLayout rl = new RelativeLayout(this);

       Button btn1 = new Button(this);
       btn1.setText("----------------------");
       btn1.setId(1);

       RelativeLayout.LayoutParams lp1 = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
       lp1.addRule(RelativeLayout.ALIGN_PARENT_TOP);
       lp1.addRule(RelativeLayout.CENTER_HORIZONTAL, RelativeLayout.TRUE);
       // btn1 位于父 View 的顶部，在父 View 中水平居中
       rl.addView(btn1, lp1 );

       Button btn2 = new Button(this);
       btn2.setText("|\n|\n|\n|\n|\n|");
       btn2.setId(2);

       RelativeLayout.LayoutParams lp2 = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
       lp2.addRule(RelativeLayout.BELOW, 1);
       lp2.addRule(RelativeLayout.ALIGN_LEFT, 1);
       // btn2 位于 btn1 的下方、其左边和 btn1 的左边对齐
       rl.addView(btn2, lp2);

       Button btn3 = new Button(this);
       btn3.setText("|\n|\n|\n|\n|\n|");
       btn3.setId(3);

       RelativeLayout.LayoutParams lp3 = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
      lp3.addRule(RelativeLayout.BELOW, 1);
       lp3.addRule(RelativeLayout.RIGHT_OF, 2);
       lp3.addRule(RelativeLayout.ALIGN_RIGHT, 1);
       // btn3 位于 btn1 的下方、btn2 的右方且其右边和 btn1 的右边对齐（要扩充）
       rl.addView(btn3,lp3);

       Button btn4 = new Button(this);
       btn4.setText("--------------------------------------------");
       btn4.setId(4);

       RelativeLayout.LayoutParams lp4 = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
       lp4.addRule(RelativeLayout.BELOW, 2);
       lp4.addRule(RelativeLayout.CENTER_HORIZONTAL, RelativeLayout.TRUE);
       // btn4 位于 btn2 的下方，在父 Veiw 中水平居中
       rl.addView(btn4,lp4);


       setContentView(rl);