Android_Fragment实现Tab

最新推荐文章于 2021-05-28 15:47:18 发布

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本文介绍了如何在Android应用中使用Fragment实现Tab功能。主要分为两个步骤：一是设计布局，包括主界面的布局，主要由一个Fragment显示内容和RadioGroup组成；二是编写代码，特别是Fragment布局文件的创建。

一.布局

二.代码

1.先写布局文件

主界面的布局文件主要是分两部分：上面是一个实现Fragment中的内容,下面是RadioGroup

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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/ll"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="#006644" >

        <RadioGroup
            android:id="@+id/rg"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal" >

            <RadioButton
                android:id="@+id/rb_message"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:button="@null"
                android:checked="true"
                android:drawableTop="@android:drawable/btn_star"
                android:gravity="center"
                android:text="消息" />

            <RadioButton
                android:id="@+id/rb_contact"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:button="@null"
                android:drawableTop="@android:drawable/btn_star"
                android:gravity="center"
                android:text="联系人" />

            <RadioButton
                android:id="@+id/rb_dynamic"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:button="@null"
                android:drawableTop="@android:drawable/btn_star"
                android:gravity="center"
                android:text="动态" />

            <RadioButton
                android:id="@+id/rb_setting"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:button="@null"
                android:drawableTop="@android:drawable/btn_star"
                android:gravity="center"
                android:text="设置" />
        </RadioGroup>
    </LinearLayout>

    <FrameLayout
        android:id="@+id/fl_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@id/ll" >
    </FrameLayout>

</RelativeLayout>

四个Fragment中的布局文件

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

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:orientation="vertical" >

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:src="@android:drawable/btn_star" />

        <TextView
            android:id="@+id/tv_content"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:padding="10dp"
            android:textSize="20sp" />
    </LinearLayout>

</RelativeLayout>

写四个Fragment来加载对应的布局

package com.example.fragment;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class Fragment_Contact extends Fragment {

	private TextView tv_content;

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {

		View view = inflater.inflate(R.layout.fragment_main, null);
		tv_content = (TextView) view.findViewById(R.id.tv_content);
		tv_content.setText("联系人");

		return view;
	}

}

package com.example.fragment;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class Fragment_Dynamic extends Fragment {

	private TextView tv_content;

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {

		View view = inflater.inflate(R.layout.fragment_main, null);
		tv_content = (TextView) view.findViewById(R.id.tv_content);
		tv_content.setText("动态");

		return view;
	}
}

package com.example.fragment;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class Fragment_message extends Fragment {

	private TextView tv_content;

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {

		View view = inflater.inflate(R.layout.fragment_main, null);
		tv_content = (TextView) view.findViewById(R.id.tv_content);
		tv_content.setText("消息");

		return view;
	}
	
	

}

package com.example.fragment;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class Fragment_Setting extends Fragment {

	private TextView tv_content;

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {

		View view = inflater.inflate(R.layout.fragment_main, null);
		tv_content = (TextView) view.findViewById(R.id.tv_content);
		tv_content.setText("设置");

		return view;
	}
	
	

}

主界面中实现Tab的切换

package com.example.fragment;

import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.util.Log;
import android.view.Window;
import android.widget.FrameLayout;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;

public class MainActivity extends Activity {

	protected static final String TAG = "MainActivity";
	private RadioGroup rg;
	private RadioButton rb_message;
	private RadioButton rb_contact;
	private RadioButton rb_dynamic;
	private RadioButton rb_setting;
	private FrameLayout fl_content;
	private Fragment_message fragment_message;
	private Fragment_Contact fragment_contact;
	private Fragment_Dynamic fragment_dynamic;
	private Fragment_Setting fragment_setting;

	private FragmentManager fragmentManager; // 管理Fragment

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		requestWindowFeature(Window.FEATURE_NO_TITLE);
		setContentView(R.layout.activity_main);

		init();

		// 得到一个Fragment的管理者
		fragmentManager = getFragmentManager();
		// 开启一个Fragment事务
		FragmentTransaction transaction = fragmentManager.beginTransaction();
		fragment_message = new Fragment_message();
		transaction.add(R.id.fl_content, fragment_message);
		transaction.commit();

		Log.i(TAG, "消息的Fragment创建成功");

		// RadioGroup的点击事件
		rg.setOnCheckedChangeListener(new OnCheckedChangeListener() {

			// transaction = fragmentManager.beginTransaction();
			// hideFragments(transaction);

			@Override
			public void onCheckedChanged(RadioGroup arg0, int arg1) {

				// 开启一个Fragment事务
				FragmentTransaction transaction = fragmentManager.beginTransaction();
				hideFragments(transaction);

				if (arg1 == rb_message.getId()) {
					if (fragment_message == null) {
						fragment_message = new Fragment_message();
						transaction.add(R.id.fl_content, fragment_message);
					} else {
						transaction.show(fragment_message);
					}

					Log.i(TAG, "选中了消息的按钮");

				} else if (arg1 == rb_contact.getId()) {
					if (fragment_contact == null) {
						fragment_contact = new Fragment_Contact();
						transaction.add(R.id.fl_content, fragment_contact);
					} else {
						transaction.show(fragment_contact);
					}

					Log.i(TAG, "选中了联系人的按钮");

				} else if (arg1 == rb_dynamic.getId()) {
					if (fragment_dynamic == null) {
						fragment_dynamic = new Fragment_Dynamic();
						transaction.add(R.id.fl_content, fragment_dynamic);
					} else {
						transaction.show(fragment_dynamic);
					}

					Log.i(TAG, "选中了动态的按钮");

				} else if (arg1 == rb_setting.getId()) {
					if (fragment_setting == null) {
						fragment_setting = new Fragment_Setting();
						transaction.add(R.id.fl_content, fragment_setting);
					} else {
						transaction.show(fragment_setting);
					}

					Log.i(TAG, "选中了设置的按钮");

				}
				transaction.commit();
			}
		});

	}

	/**
	 * 控件的实例化
	 */
	private void init() {

		rg = (RadioGroup) findViewById(R.id.rg);
		rb_message = (RadioButton) findViewById(R.id.rb_message);
		rb_contact = (RadioButton) findViewById(R.id.rb_contact);
		rb_dynamic = (RadioButton) findViewById(R.id.rb_dynamic);
		rb_setting = (RadioButton) findViewById(R.id.rb_setting);
		fl_content = (FrameLayout) findViewById(R.id.fl_content);

	}

	/**
	 * 将所有的Fragment都置为隐藏状态。
	 * 
	 * @param transaction
	 *            用于对Fragment执行操作的事务
	 */
	private void hideFragments(FragmentTransaction transaction) {

		if (fragment_message != null) {
			transaction.hide(fragment_message);
		}
		if (fragment_contact != null) {
			transaction.hide(fragment_contact);
		}
		if (fragment_dynamic != null) {
			transaction.hide(fragment_dynamic);
		}
		if (fragment_setting != null) {
			transaction.hide(fragment_setting);
		}

	}

}