android fragment切换多页时保证切换前的页的状态不被销毁（红色字体）

最新推荐文章于 2022-12-23 16:37:25 发布

云开-秋秋

最新推荐文章于 2022-12-23 16:37:25 发布

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本文链接：https://blog.youkuaiyun.com/qiufeng_xinqing/article/details/52455586

本文介绍了一个自定义的FragmentPagerAdapter——SectionsPagerAdapter，用于管理多个Fragment的显示与切换。该适配器支持三种不同的活动：图像压缩、文件重命名及监视狗功能。每个活动都作为一个Fragment实例，并通过传入的KSMessage消息对象初始化。

package ks.pager;

import android.os.Message;
import android.os.Parcelable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.view.ViewGroup;

import ks.msg.KSMessage;
import ks.photo.KSPhotoMainActivity;
import ks.rename.KSRenameMainActivity;
import ks.watchdog.KSWatchdogMainActivity;

/**
 * Created by BaiKaiShui on 2016/9/5.
 */
public class SectionsPagerAdapter  extends FragmentPagerAdapter {

    private final int ACTIVITY_COUNT = 3;
    private MyFragment [] fragmentes = new MyFragment[ACTIVITY_COUNT];
    private KSMessage massege = null;

    public SectionsPagerAdapter(FragmentManager fm, KSMessage msg) {
        super(fm);
        massege = msg;
    }

    @Override
    public Parcelable saveState() {
        return super.saveState();
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
<span style="background-color: rgb(255, 102, 102);"><span style="white-space:pre">	</span>// 保证状态栈不销毁
        //super.destroyItem(container, position, object);</span>
    }

    @Override
    public Fragment getItem(int position) {
        switch(position) {
            case 0:
                return (fragmentes[position] = KSPhotoMainActivity.newInstance(position, massege));
            case 1:
                return (fragmentes[position] = KSRenameMainActivity.newInstance(position, massege));
            case 2:
                return (fragmentes[position] = KSWatchdogMainActivity.newInstance(position, massege));
        }

        return null;
    }

    @Override
    public int getCount() {
        return ACTIVITY_COUNT;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        switch (position) {
            case 0:
                return "图像压缩";
            case 1:
                return "文件重命名";
            case 2:
                return "监视狗";
        }
        return null;
    }

    public void onEvent(Message msg){
        for (int i = 0; i < ACTIVITY_COUNT; i++) {
            if(fragmentes[i] != null)
                fragmentes[i].onEvent(msg);
        }
    }

    public void onActivityResult(String name, String dir){
        for (int i = 0; i < ACTIVITY_COUNT; i++) {
            if(fragmentes[i] != null)
                fragmentes[i].onActivityResult(name, dir);
        }
    }
}