Android Fragment的静态注册和动态注册创建步骤

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我是靠谱客的博主甜甜雪碧，最近开发中收集的这篇文章主要介绍Android Fragment的静态注册和动态注册创建步骤，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

一、fragment静态注册创建方法及步骤

1.创建一个StaticFragment.java文件继承Fragment类和一个static_fragment.xml文件完成fragment的布局。在StaticFragment.java中重载onCreateView(……)方法，通过调用inflater.inflate(……)方法并传入布局资源ID生成fragment的视图资源，并绑定static_fragment.xml中的相关组件然后实现其功能。实现代码如下：

static_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<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"
  tools:context=".StaticFragment"
  android:orientation="vertical">
  <Button
    android:id="@+id/btn_fm"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="这是fragment静态注册"
    android:textAllCaps="false">
      </Button>
  <EditText
    android:id="@+id/et_fm"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="请输入你要改变的内容：">
      </EditText>
</LinearLayout>

StaticFragment.java

package com.example.myapplication;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
public class StaticFragment extends Fragment {
  private Button mBtnFm;
  private EditText mEtFm;
  @Nullable
  @Override
  public View onCreateView(@NonNull LayoutInflater inflater,
               @Nullable ViewGroup container,
               @Nullable Bundle savedInstanceState) {
    //fragment的视图资源是直接通过调用inflater.inflate(……)方法并传入布局资源ID生成的。
    View v = inflater.inflate(R.layout.static_fragment,
                 container,false);
    mEtFm = v.findViewById(R.id.et_fm);
    mBtnFm = v.findViewById(R.id.btn_fm);
    mBtnFm.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        mBtnFm.setText(mEtFm.getText().toString());
      }
    });
    return v;
  }
}

2.在主布局activity_main.xml文件中绑定fragment布局文件。

实现代码如下：

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<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"
  tools:context=".MainActivity"
  android:orientation="vertical">
  <TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="这是主布局"
    android:textColor="@color/colorAccent"
    android:textSize="30sp">
  </TextView>
  <TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="下面是fragment的布局"
    android:textColor="@color/colorPrimaryDark"
    android:textSize="30sp">
  </TextView>
  <fragment
    android:id="@+id/static_fm"
    android:name="com.example.myapplication.StaticFragment"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

  </fragment>
</LinearLayout>

注意：布局文件中加fragment节点，name属性必须填写完整的路径

MainActivity.java

package com.example.myapplication;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
  }
}

演示：

二、fragment动态注册创建方法及步骤

1.新建一个项目，创建2个Fragment继承类分别为MyFragment1.java和MyFragment2.java，然后创建2个布局文件分别为fragment1.xml和fragment2.xml.详细代码如下：

fragment1.xml

<?xml version="1.0" encoding="utf-8"?>
<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"
  tools:context=".MyFragment1"
  android:gravity="center"
  android:background="@color/colorPrimaryDark">
  <TextView
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:gravity="center"
    android:text="@string/hello_blank_fragment"
    android:textSize="30sp"
    android:textAllCaps="false"
    android:textColor="#F70505">
  </TextView>
</LinearLayout>

MyFragment1.java

package com.example.myapplication;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class MyFragment1 extends Fragment {
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
               Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment1, container, false);
  }
}

fragment2.xml

<?xml version="1.0" encoding="utf-8"?>
<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"
  tools:context=".MyFragment2"
  android:gravity="center"
  android:background="@color/colorAccent">
  <TextView
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:gravity="center"
    android:text="@string/hello_blank_fragment"
    android:textSize="30sp"
    android:textAllCaps="false"
    android:textColor="#03FAE3">
  </TextView>
</LinearLayout>

MyFragment2.java

package com.example.myapplication;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class MyFragment2 extends Fragment {
  @Override
  public View onCreateView(LayoutInflater inflater,
               ViewGroup container,
               Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment2, container, false);
  }
}

上述代码与静态创建的区别不大。

2.以代码的形式将fragment添加到activity需要在activity里直接调用FragmentManager。

FragmentManager fm = getSupportFragmentManager();

然后通过代码块：

FragmentTransaction ts = fm.beginTransaction();
Fragment mfg1 = new MyFragment1();
ts.add(R.id.fragment_container,mfg1);
ts.commit();

提交一个fragment事务。其核心是ts.add(……)方法。

详细代码如下：

activity_main.xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
  tools:context=".MainActivity">
  <LinearLayout
    android:id="@+id/linear"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:layout_alignParentBottom="true">
    <Button
      android:id="@+id/btn_dy1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="fragment1"
      android:textColor="@color/colorAccent"
      android:textSize="30sp">
    </Button>
    <Button
      android:id="@+id/btn_dy2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="fragment2"
      android:textColor="@color/colorPrimaryDark"
      android:textSize="30sp">
    </Button>
  </LinearLayout>
  <FrameLayout
    android:id="@+id/fragment_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_above="@id/linear">
  </FrameLayout>
</RelativeLayout>

注意：fragment模块一般用FrameLayout布局承载

MainActivity.java

package com.example.myapplication;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
  private Button mBtnDy1;
  private Button mBtnDy2;
  FragmentManager fm;
  Fragment mfg1;
  Fragment mfg2;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    fm = getSupportFragmentManager();
    mBtnDy1 = findViewById(R.id.btn_dy1);
    mBtnDy2 = findViewById(R.id.btn_dy2);
    mBtnDy1.setOnClickListener(this);
    mBtnDy2.setOnClickListener(this);
  }
  @Override
  public void onClick(View v) {
    clearSelection();//清除按钮状态
    FragmentTransaction ts = fm.beginTransaction();
    hideFragments(ts);
    switch (v.getId()){
      case R.id.btn_dy1:
        mBtnDy1.setBackgroundColor(0xff0000ff);
        if(mfg1 == null){
          mfg1 = new MyFragment1();
          ts.add(R.id.fragment_container,mfg1);
        }else {
          ts.show(mfg1);
        }
        break;
      case R.id.btn_dy2:
        mBtnDy2.setBackgroundColor(0xff0000ff);
        if(mfg2 == null){
          mfg2 = new MyFragment2();
          ts.add(R.id.fragment_container,mfg2);
        }else {
          ts.show(mfg2);
        }
        break;
        default:
          break;
    }
    ts.commit();
  }
//  将所有的Fragment都置为隐藏状态。
  private void hideFragments(FragmentTransaction transaction) {
    if (mfg1 != null) {
      transaction.hide(mfg1);
    }
    if (mfg2 != null) {
      transaction.hide(mfg2);
    }
  }
//   清除掉所有的选中状态。
  private void clearSelection() {
    mBtnDy1.setBackgroundColor(0xffffffff);
    mBtnDy2.setBackgroundColor(0xffffffff);
  }
}

演示：