通过编码方式实现软件的布局
程序运行结果图示：
需要注意的是：
1)一个控件只能有一个父元素，如果多次添加
09-02 11:01:34.785: E/AndroidRuntime(23954):
java.lang.RuntimeException: Unable to start activity ComponentInfo{cn.itcast.codeui/cn.itcast.codeui.MainActivity}: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
1、把新建项目时的main.xml文件删除
2、MainActivity
package com.njupt.codeui;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.view.ViewGroup.LayoutParams;import android.widget.Button;import android.widget.EditText;import android.widget.LinearLayout;import android.widget.TextView;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);LayoutParams params = new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT); LayoutParams params1 = new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT);LayoutParams params2 = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);LinearLayout linearLayout = new LinearLayout(this);linearLayout.setOrientation(LinearLayout.VERTICAL);TextView tv = new TextView(this);tv.setText("请输入你的老婆的姓名");linearLayout.addView(tv,params1);EditText et = new EditText(this);et.setText("章泽天");linearLayout.addView(et,params1);Button bt = new Button(this);bt.setText("确定");linearLayout.addView(bt,params2);setContentView(linearLayout,params);}@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;}}