java代码添加view

package com.example.demo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Gravity;
import android.widget.Button;
import android.widget.LinearLayout;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

///使用java代码动态添加子view
oneWay();
}

private void oneWay(){
Button button  = new Button(this);
button.setText("One");
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
//此处相当于布局文件中的Android:layout_gravity属性
lp.gravity = Gravity.RIGHT;
button.setLayoutParams(lp);
//此处相当于布局文件中的Android：gravity属性
button.setGravity(Gravity.CENTER);

LinearLayout linear = new LinearLayout(this);
//注意，对于LinearLayout布局来说，设置横向还是纵向是必须的！否则就看不到效果了。
linear.setOrientation(LinearLayout.VERTICAL);
linear.addView(button);
linear.setBackgroundColor(0x30ffffff);
setContentView(linear);
}

private void anotherWay(){
Button button  = new Button(this);
button.setText("One");
//此处相当于布局文件中的Android：gravity属性
button.setGravity(Gravity.CENTER);

LinearLayout linear = new LinearLayout(this);
//注意，对于LinearLayout布局来说，设置横向还是纵向是必须的！否则就看不到效果了。
linear.setOrientation(LinearLayout.VERTICAL);

LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
//此处相当于布局文件中的Android:layout_gravity属性
lp.gravity = Gravity.RIGHT;

linear.addView(button, lp);
setContentView(linear);
}

}