前段时间学习了android,了解到android主要是使用xml布局文件进行布局的,但是对于一些动态的界面,就需要使用代码动态生成布局。
Android 除了可以加载xml文件,显示布局外,也可以代码生成布局,并通过setContentView(View view)方法显示布局。单独的一层布局,如一个主布局加一个控件(如Button\imageView等)动态生成代码比较简单,下面只给出示例代码:
- package com.example.android_dongtaishengcheng;
- import android.os.Bundle;
- import android.app.Activity;
- import android.content.Intent;
- import android.view.Menu;
- import android.view.View;
- import android.widget.Button;
- import android.widget.RelativeLayout;
- import android.widget.Toast;
- import android.widget.RelativeLayout.LayoutParams;
- public class MainActivity extends Activity
- {
- RelativeLayout relativeLayout = null;
- private Button button;
- @Override
- protected void onCreate(Bundle savedInstanceState)
- {
- super.onCreate(savedInstanceState);
- relativeLayout = new RelativeLayout(this);
- LayoutParams params = new LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT,
- RelativeLayout.LayoutParams.MATCH_PARENT);
- relativeLayout.setLayoutParams(params);
- relativeLayout.setBackgroundResource(R.color.back);
- setContentView(relativeLayout);
- button = new Button(this);
- LayoutParams params2 = new LayoutParams(300, 300);
- button.setLayoutParams(params2);
- params2.addRule(RelativeLayout.CENTER_IN_PARENT);
- button.setText("hello");
- relativeLayout.addView(button);
- button.setOnClickListener(new View.OnClickListener()
- {
- @Override
- public void onClick(View v)
- {
- // TODO Auto-generated method stub
- startActivity(new Intent(MainActivity.this,SecondActivity.class));
- }
- });
- }
- }
情景描述:父布局是一个线性布局,其子布局按竖直方向排列,子布局的子布局也是一个线性布局,按水平方向排列。
其实很简单,关键点在于,如何控制主布局的子布局换行显示,即实现Orientation = "vertical"。可以在子布局外在加一层布局,即下面的drawParent()方法,该方法用来生成父布局的直接子布局,drawView()方法用来生成直接子布局的子布局(该布局也是多层嵌套)。可以实现如下图效果:
贴出代码如下:
- /**
- *
- */
- package com.example.android_dongtaishengcheng;
- import android.R.integer;
- import android.app.Activity;
- import android.content.Context;
- import android.os.Bundle;
- import android.view.Gravity;
- import android.view.View;
- import android.widget.Button;
- import android.widget.LinearLayout;
- import android.widget.RelativeLayout;
- import android.widget.LinearLayout.LayoutParams;
- /**
- * @author zhiyuan
- *
- * 2014-5-29 上午10:44:44
- *
- */
- public class SecondActivity extends Activity
- {
- LinearLayout layout = null;
- LinearLayout line2 = null;
- LinearLayout line3 = null;
- LinearLayout line4 = null;
- @Override
- protected void onCreate(Bundle savedInstanceState)
- {
- // TODO Auto-generated method stub
- super.onCreate(savedInstanceState);
- layout = new LinearLayout(this);
- LayoutParams params = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
- layout.setLayoutParams(params);
- layout.setOrientation(LinearLayout.VERTICAL);
- setContentView(layout);
- // layout.addView(drawView(this));
- line2 = (LinearLayout) drawParent(this);
- line3 = (LinearLayout) drawParent(this);
- line4 = (LinearLayout) drawParent(this);
- for (int i = 0; i < 2; i++)
- {
- line2.addView(drawView(SecondActivity.this, i));
- }
- for (int i = 0; i < 4; i++)
- {
- line3.addView(drawView(SecondActivity.this, i));
- }
- for(int i = 0; i < 5; i++){
- line4.addView(drawView(SecondActivity.this, i));
- }
- layout.addView(line2);
- layout.addView(line3);
- layout.addView(line4);
- }
- //生成子布局的子布局
- public View drawView(Context context, int count)
- {
- LinearLayout layout = new LinearLayout(context);
- LayoutParams params = new LayoutParams(LayoutParams.MATCH_PARENT,
- LayoutParams.WRAP_CONTENT, 1);
- params.gravity = Gravity.CENTER;
- layout.setOrientation(LinearLayout.HORIZONTAL);
- layout.setLayoutParams(params);
- if (count == 1)
- {
- layout.setBackgroundResource(R.color.back);
- }
- RelativeLayout relativeLayout = new RelativeLayout(context);
- android.widget.RelativeLayout.LayoutParams params3 = new android.widget.RelativeLayout.LayoutParams(
- android.widget.RelativeLayout.LayoutParams.MATCH_PARENT,
- android.widget.RelativeLayout.LayoutParams.WRAP_CONTENT);
- relativeLayout.setLayoutParams(params3);
- /*
- * ImageView imageView = new ImageView(context); LayoutParams params2 = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
- */
- Button imageView = new Button(context);
- android.widget.RelativeLayout.LayoutParams params2 = new android.widget.RelativeLayout.LayoutParams(android.widget.RelativeLayout.LayoutParams.WRAP_CONTENT,
- android.widget.RelativeLayout.LayoutParams.WRAP_CONTENT);
- //imageView.setGravity(RelativeLayout.CENTER_IN_PARENT);
- imageView.setText("测试");
- params2.addRule(RelativeLayout.CENTER_IN_PARENT);
- // imageView.setBackgroundResource(R.drawable.ic_launcher);
- imageView.setLayoutParams(params2);
- /*
- * TextView textView = new TextView(context); LayoutParams params3 = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); textView.setText("测试专用");
- * textView.setLayoutParams(params3);
- */
- relativeLayout.addView(imageView);
- // layout.addView(textView);
- layout.addView(relativeLayout);
- return layout;
- }
- //生成主布局的子布局
- public View drawParent(Context context)
- {
- LinearLayout layout = new LinearLayout(context);
- LayoutParams params = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
- // params.gravity = Gravity.CENTER_HORIZONTAL;
- layout.setOrientation(LinearLayout.HORIZONTAL);
- layout.setLayoutParams(params);
- return layout;
- }
- }
附Demo下载地址: http://download.youkuaiyun.com/detail/laoziyueguo3/7423939