1.靜态加載fragment
package com.example.shinelon.diyfragment;
import android.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
//自定義一個類繼承Fragment,繼承這個android.app.Fragment,v4那個已經被淘汰,詳情見菜鳥教程,及fragment的作用
public class Demo2 extends Fragment{
@Nullable
//重寫onCreate方法
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
//用inflate加載布局頁面,布局頁面命名規則 fragment_xxxx
View view = inflater.inflate(R.layout.fragment2, null);
return view;
}
}
在activity_main布局中加載fragment
name屬性值目前所要加載的fragment的全類名
标簽全小寫
<fragment
android:name="com.example.shinelon.diyfragment.Demo3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"></fragment>
2.動态加載fragment(橫豎屏切換加載不同的頁面)
![](https://img.laitimes.com/img/9ZDMuAjOiMmIsIjOiQnIsIiZpdmL3QTMzEzM1AjMzAzMwkTMwIzLc52YucWbp5GZzNmLn9Gbi1yZtl2Lc9CX6MHc0RHaiojIsJye.gif)
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//擷取手機螢幕
WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);
int width = wm.getDefaultDisplay().getWidth();
int height = wm.getDefaultDisplay().getHeight();
//擷取fragment管理者
android.app.FragmentManager manager = getFragmentManager();
//管理者開啟事務
// 開啟一個事物,事物是執行一段邏輯,要麼同時成功,要麼同時失敗
FragmentTransaction transaction = manager.beginTransaction();
if(height>width){
//加載之前的寫好的頁面
transaction.replace(R.id.LL,new Demo1());
}else {
transaction.replace(R.id.LL,new Demo2());
}
//送出一個事務,業務邏輯完成後一定要送出(commit)事務
transaction.commit();
}
}
activity_main中
<LinearLayout
android:id="@+id/LL"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"></LinearLayout>
3.Fragment與Activity的互動
左邊的Button是一個fragment,右邊的TextView在Activity上
fragment_layout
簡單建立一個布局,上面隻寫了一個Button
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="@+id/btn"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="button"/>
</LinearLayout>
Fragment
/和之前的操作一樣,先建立一個類繼承app.Fragment,用inflate加載剛才寫的布局
public class Fragment extends android.app.Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_layout, null);
//設定Button的監聽,用匿名内部類的方法
// 這裡的view應該相當于上下文對象,了解的不是很好
view.findViewById(R.id.btn).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//用getActivity方法,得到Activity activity = getActivity();
//指定是MainActivity,然後進行強制轉換
MainActivity m = (MainActivity) getActivity();
m.update("123456");
}
});
return view;
}
}
activity_main
主布局檔案中,寫了一個線性布局,用來放Fragment
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
tools:context=".MainActivity">
<LinearLayout
android:id="@+id/LL"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical"></LinearLayout>
<TextView
android:id="@+id/tv"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="hello Lenovo" />
</LinearLayout>
MainActivity
public class MainActivity extends AppCompatActivity {
TextView tv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = findViewById(R.id.tv);
FragmentManager manager = getFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.LL,new Fragment());
transaction.commit();
}
//将修改文字封裝成一個方法,然後在Button的點選事件中,直接調用這個方法
public void update(String s){
tv.setText(s);
}
}
4.Fragment與Fragment之間的資料互傳
效果與之前類似,不再做示範
Fragment2
//操作與上一個案例相同,布局檔案也很簡單,就是一個TextView
public class Fragment2 extends Fragment{
@Nullable
TextView tv;
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment2_layout, null);
tv = view.findViewById(R.id.tv);
return view;
}
public void setData(String s){
tv.setText(s);
}
}
Fragment1
public class Fragment1 extends Fragment{
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment1_layout, null);
view.findViewById(R.id.bt).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
MainActivity mactivity = (MainActivity) getActivity();
//這裡用一個getFragmentManger方法,得到manger對象
FragmentManager manager = mactivity.getFragmentManager();
//用manger找到這個取名為"f2"的fragment
//和上一個案例不同之處
Fragment2 f2 = (Fragment2) manager.findFragmentByTag("f2");
f2.setData("123654");
}
});
return view;
}
}
activity_main
主布局檔案中就放兩個LineLayout
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:orientation="horizontal">
<LinearLayout
//設定id,必須要設定orientation的方向
android:id="@+id/LL1"
android:layout_weight="1"
android:orientation="vertical"
android:layout_width="0dp"
android:layout_height="match_parent"></LinearLayout>
<LinearLayout
android:id="@+id/LL2"
android:layout_weight="1"
android:orientation="vertical"
android:layout_width="0dp"
android:layout_height="match_parent"></LinearLayout>
</LinearLayout>
MainActivity
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager f1 = getFragmentManager();
FragmentTransaction t1 = f1.beginTransaction();
//和上一個不同之處,在後面加了一個自取的fragment名字
//用于前面FragmentManager找到這個取名的fragment
t1.replace(R.id.LL1,new Fragment1(),"f1");
t1.commit();
FragmentManager f2 = getFragmentManager();
FragmentTransaction t2 = f2.beginTransaction();
t2.replace(R.id.LL2,new Fragment2(),"f2");
t2.commit();
}
}