Android中的Fragment使用详解之页面加载
静态加载
1、Fragment布局
<?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:id='@+id/textView1'
android:layout_width='wrap_content'
android:layout_height='wrap_content'
android:text='TextView' />
<Button
android:id='@+id/button1'
android:layout_width='wrap_content'
android:layout_height='wrap_content'
android:text='Button' />
</LinearLayout>
2、编写我的MyFragment
package com.cx.testdemo;
import android.annotation.SuppressLint;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
@SuppressLint('NewApi')
public class MyFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// layout文件转化为View对象(需要加载的布局文件,加载layout的父ViewGroup,是否返回父窗体ViewGroup)
View view = inflater.inflate(R.layout.fragment, container, false);
TextView textView = (TextView) view.findViewById(R.id.textView1);
textView.setText('静态加载');
return view;
}
}
注意:在引入jar包时要引入import android.app.Fragment;,不能引入import android.support.v4.app.Fragment;。引入后者时,代码不会报错,但运行时报错。
3、在Activity的布局中使用MyFragment
<?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' >
<fragment
android:id='@+id/fragment'
android:layout_width='wrap_content'
android:layout_height='wrap_content'
android:name='com.cx.testdemo.MyFragment'/>
</LinearLayout>
注意:一定要加id属性,虽然在其他地方用不到。
4、在Activity中使用
package com.cx.testdemo;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity2 extends Activity {
private TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.main2);
//直接使用fragment布局文件中的Button。静态加载特点,在Activity中对Fragment中的控件进行改变。
Button button = (Button) findViewById(R.id.button1);
textView = (TextView) findViewById(R.id.textView1);
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
textView.setText('改变');
}
});
}
}
动态加载
动态加载的前两步与静态加载相同,这里直接从第三步开始
3、Activity的布局文件中将上面3中布局的fragment换成LinearLayout
<?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' >
<LinearLayout
android:id='@+id/frame'
android:layout_width='match_parent'
android:layout_height='wrap_content'
android:orientation='vertical' >
</LinearLayout>
</LinearLayout>
4、在Activity中动态加载fragment
package com.cx.testdemo;
/*
* 动态加载
*/
import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
public class MainActivity2 extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.main2);
MyFragment2 fragment2 = new MyFragment2();
//获取Fragment管理者
FragmentManager fragmentManager = getFragmentManager();
//通过Fragment管理者开启一个事务的对象
FragmentTransaction beginTransaction = fragmentManager.beginTransaction();
//(添加到的布局id,Fragment)
beginTransaction.add(R.id.frame, fragment2);
//返回键回退效果
beginTransaction.addToBackStack(null);
beginTransaction.commit();
}
}
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