Android LayoutInflater.inflate(int resource, ViewGroup root, boolean attachToRoot)的参数理解
方法inflate(int resource, ViewGroup root, boolean attachToRoot) 中
第一个参数传入布局的资源ID，生成fragment视图，第二个参数是视图的父视图，通常我们需要父
视图来正确配置组件。第三个参数告知布局生成器是否将生成的视图添加给父视图。
我们新建一个项目测试一下：
activity_main.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="match_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="helloworld" />
<FrameLayout
android:id="@+id/framelayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</FrameLayout>
</LinearLayout>
fragment_main.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="match_parent"
android:orientation="vertical" >
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
MainActivity.java：第一种情况没有attachToRoot参数，默认告知布局生成器将生成的视图添加给父视图，
1 public class MainActivity extends Activity { 2 3 @Override 4 protected void onCreate(Bundle savedInstanceState) { 5 super.onCreate(savedInstanceState); 6 setContentView(R.layout.activity_main); 7 ViewGroup vg = (ViewGroup) findViewById(R.id.framelayout); 8 View v = LayoutInflater.from(this).inflate(R.layout.fragment_main, vg); 9 // View v = LayoutInflater.from(this).inflate(R.layout.fragment_main, vg, false); 10 // View v = LayoutInflater.from(this).inflate(R.layout.fragment_main, vg, true); 11 12 13 } 14 15 16 }
第二种情况：参数attachToRoot设为false，不将生成的视图（fragmnt_main）添加给父视图(activity_main)，
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewGroup vg = (ViewGroup) findViewById(R.id.framelayout);
// View v = LayoutInflater.from(this).inflate(R.layout.fragment_main, vg);
View v = LayoutInflater.from(this).inflate(R.layout.fragment_main, vg, false);
// View v = LayoutInflater.from(this).inflate(R.layout.fragment_main, vg, true);
}
}
第三种情况：参数attachToRoot设为true，将生成的视图（fragmnt_main）添加给父视图(activity_main)，
public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ViewGroup vg = (ViewGroup) findViewById(R.id.framelayout); // View v = LayoutInflater.from(this).inflate(R.layout.fragment_main, vg); // View v = LayoutInflater.from(this).inflate(R.layout.fragment_main, vg, false); View v = LayoutInflater.from(this).inflate(R.layout.fragment_main, vg, true); } }
