Android:用编程的方式开发UI组件

package com.example.codeview;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup;import android.widget.Button;import android.widget.LinearLayout;import android.widget.TextView;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);// 创建一个线性布局管理器LinearLayout layout = new LinearLayout(this);// 设置Activity显示Layoutsuper.setContentView(layout);// 设置垂直布局方向layout.setOrientation(LinearLayout.VERTICAL);// 创建一个TextViewfinal TextView show = new TextView(this);// 创建一个按钮Button btn = new Button(this);btn.setText(R.string.ok);btn.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT));// 向Layout容器中添加TextViewlayout.addView(show);// 向Layout容器中添加按钮layout.addView(btn);// 为按钮绑定一个事件监听器btn.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubshow.setText("Hello,Android," + new java.util.Date());}});}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}