ViewGroup的方法addView的使用

一、前导

ViewGroup是View的子类，ViewGroup通过addView()向自己的容器中添加View。而添加的这个View也可以是一个ViewGroup，这样，添加的这个ViewGroup又可以addView(),理论上可以一直这样一层一层的添加。

二、使用举例

注意：先addView()，然后才能调用view.findViewById()。

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/add"
        android:clickable="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <LinearLayout
            android:id="@+id/container"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

            <Button
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Button" />

            <Button
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Button" />

            <LinearLayout
                  android:id="@+id/container2"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical" >
            </LinearLayout>
        </LinearLayout>
    </ScrollView>

</LinearLayout>

add_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/container3"
    android:orientation="vertical" >

    <Button
        android:id="@+id/add_btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="add button" />

</LinearLayout>

add_view2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <Button
        android:id="@+id/add_btn2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="add button2" />

</LinearLayout>

MainActivity

package com.example.testaddview;

import android.app.Activity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.LinearLayout;
import android.widget.Toast;

public class MainActivity extends Activity {
	private LinearLayout container, container2;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		container = (LinearLayout) this.findViewById(R.id.container);
		container2 = (LinearLayout) this.findViewById(R.id.container2);

		this.findViewById(R.id.add).setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				View view = LayoutInflater.from(MainActivity.this).inflate(R.layout.add_view, null);
//				container2.addView(view);
				container.addView(view);//2 methods are all useful.

				final LinearLayout container3 = (LinearLayout) view.findViewById(R.id.container3);
				view.findViewById(R.id.add_btn).setOnClickListener(new OnClickListener() {
					
					@Override
					public void onClick(View v) {
						View view2 = LayoutInflater.from(MainActivity.this).inflate(R.layout.add_view2, null);
						container3.addView(view2);
						
						view2.findViewById(R.id.add_btn2).setOnClickListener(new OnClickListener() {
							
							@Override
							public void onClick(View v) {
							Toast.makeText(getApplicationContext(), "click the button", 0).show();
							}
						});
					}
				});
			}
		});
	}

}