2011.06.03（2）——— android 1.6 launcher研究之自定义ViewGroup

2011.06.03（2）——— android 1.6 launcher研究之自定义ViewGroup


1、用xml来作为ViewGroup里面的View
参考：[url]http://www.eoeandroid.com/thread-30888-1-1.html[/url]

MyViewGroup.java

package com.lp;

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class MyViewGroup extends ViewGroup {   
    public MyViewGroup(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public MyViewGroup(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public MyViewGroup(Context context) {
        super(context);
        initializeView(context);
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        System.out.println(getChildCount());
        for(int i=0;i<getChildCount();i++){
            View view = getChildAt(i);
            view.setVisibility(View.VISIBLE);

            view.measure(r - l, b - t);
            view.layout(l, t, r, b);
        }
    }

    private void initializeView(Context context) {
        //LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        LayoutInflater inflater = LayoutInflater.from(context);
        View mycontrol = inflater.inflate(R.layout.myview, null);
        addView(mycontrol);
    }

}

myviewgroup.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="800px"
	android:layout_height="600px" 
	android:background="#F33603" 
	android:orientation="vertical">
	<Button 
		android:text="my button1" 
		android:layout_width="wrap_content" 
		android:layout_height="wrap_content" 
		/>
	<Button 
		android:text="my button2" 
		android:layout_width="wrap_content" 
		android:layout_height="wrap_content" 
		/>
	<Button 
		android:text="my button3" 
		android:layout_width="wrap_content" 
		android:layout_height="wrap_content" 
		/>
</LinearLayout>

MainActivity.java

package com.lp;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyViewGroup(this));
    }
}

针对那个网址里面的错误 只要加上view.measure(r - l, b - t);就可以里了


2、自己些子view
参考：[url]http://soft-app.iteye.com/blog/924757[/url]


MyViewGroup2.java

package com.lp;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

public class MyViewGroup2 extends ViewGroup {


    public MyViewGroup2(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public MyViewGroup2(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public MyViewGroup2(Context context) {
        super(context);
        initializeView(context);
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        System.out.println(getChildCount());
        for(int i=0;i<getChildCount();i++){
            View view = getChildAt(i);
            view.setVisibility(View.VISIBLE);

            view.measure(r - l, b - t);
            view.layout(10+i*5, 20+i*10, view.getMeasuredWidth(), view  
                    .getMeasuredHeight());
        }
    }

    private void initializeView(Context context) {
        Button btn1 = new Button(context);
        btn1.setText("按钮1");
        addView(btn1);
        Button btn2 = new Button(context);
        btn2.setText("按钮2");
        addView(btn2);
    }

}

MainActivity.java

package com.lp;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyViewGroup2(this));
    }
}

注意：
1、两者的initializeView()方法不同 前者是从xml中获取view；后者是自己编写view
[color=red]2、注意onLayout()方法
xml时
view.layout(l, t, r, b);
自己写时：
view.layout(10+i*50, 20+i*50, view.getMeasuredWidth(), view
.getMeasuredHeight());
也就是说 xml时 布局已经在xml里面说明了[/color]


另： 自定义ViewGroup的使用

1、如上面的
MainActivity.java

package com.lp;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyViewGroup2(this));
    }
}

2、layout的方式

<?xml version="1.0" encoding="utf-8"?>
<com.lp.MyViewGroup2 
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="fill_parent"  
  	android:layout_height="fill_parent">
  	<Button
  		android:text="aaa"
  		android:layout_width="wrap_content"  
  		android:layout_height="wrap_content"
  		/>
  	<Button
  		android:text="bbb"
  		android:layout_width="wrap_content"  
  		android:layout_height="60dip"
  		/>
</com.lp.MyViewGroup2>

然后 MainActivity.java

package com.lp;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}