Android学习之分段选择器的实现

周末在github上浏览了一个分段选择器的实现，其实就是一个自定义view，写了一个小demo实验了一下，感觉很不错，遂记之！

效果图：

实现很简单，主要是在fragment的填充

布局：

<?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=".activity.MainActivity">

    <com.example.wangchang.segmentcontrol.segmentcontrol.SegmentControl xmlns:segmentcontrol="http://schemas.android.com/apk/res-auto" android:id="@+id/segment_control" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_marginTop="20dp" android:textSize="13sp" segmentcontrol:colors="@color/colorPrimary" segmentcontrol:cornerRadius="5dp" segmentcontrol:direction="horizon" segmentcontrol:horizonGap="8dp" segmentcontrol:texts="我的好友|同学|同事|老师" segmentcontrol:verticalGap="8dp" />

    <FrameLayout  android:id="@+id/layFragme" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_below="@+id/segment_control" />
</RelativeLayout>

segmentcontrol:texts=”我的好友|同学|同事|老师”。用来设置分段内容。

MainActivity

package com.example.wangchang.segmentcontrol.activity;

import android.support.design.widget.Snackbar;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import com.example.wangchang.segmentcontrol.R;
import com.example.wangchang.segmentcontrol.fragment.BookFragment;
import com.example.wangchang.segmentcontrol.fragment.FavoritesFragment;
import com.example.wangchang.segmentcontrol.fragment.FindFragment;
import com.example.wangchang.segmentcontrol.fragment.LocationFragment;
import com.example.wangchang.segmentcontrol.segmentcontrol.SegmentControl;

public class MainActivity extends AppCompatActivity {
    private LocationFragment mLocationFragment;
    private FindFragment mFindFragment;
    private FavoritesFragment mFavoritesFragment;
    private BookFragment mBookFragment;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final SegmentControl show = (SegmentControl) findViewById(R.id.segment_control);
        setDefaultFragment();
        show.setOnSegmentControlClickListener(new SegmentControl.OnSegmentControlClickListener() {
            @Override
            public void onSegmentControlClick(int index) {
                FragmentManager fm = getSupportFragmentManager();
                FragmentTransaction ft = fm.beginTransaction();
                switch (index) {
                    case 0:
                        if (mLocationFragment == null) {
                            mLocationFragment = LocationFragment.newInstance("我的好友");
                        }
                        ft.replace(R.id.layFragme, mLocationFragment).commitAllowingStateLoss();
                        Snackbar.make(show, " 好友", Snackbar.LENGTH_SHORT).show();
                        break;
                    case 1:
                        if (mFindFragment == null) {
                            mFindFragment = FindFragment.newInstance("同学");
                        }
                        ft.replace(R.id.layFragme, mFindFragment).commitAllowingStateLoss();
                        Snackbar.make(show, " 同学", Snackbar.LENGTH_SHORT).show();
                        break;
                    case 2:
                        if (mFavoritesFragment == null) {
                            mFavoritesFragment = FavoritesFragment.newInstance("同事");
                        }
                        ft.replace(R.id.layFragme, mFavoritesFragment).commitAllowingStateLoss();
                        Snackbar.make(show, " 同事", Snackbar.LENGTH_SHORT).show();
                        break;
                    case 3:
                        if (mBookFragment == null) {
                            mBookFragment = BookFragment.newInstance("老师");
                        }
                        ft.replace(R.id.layFragme, mBookFragment).commitAllowingStateLoss();
                        Snackbar.make(show, " 老师", Snackbar.LENGTH_SHORT).show();
                        break;
                }
            }
        });
    }

    private void setDefaultFragment() {
        FragmentManager fm = getSupportFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();
        if (mLocationFragment == null) {
            mLocationFragment = LocationFragment.newInstance("我的好友");
            ft.replace(R.id.layFragme, mLocationFragment).commitAllowingStateLoss();
        }
    }
}

setDefaultFragment()加载默认Fragment，setOnSegmentControlClickListener监听分段选择器的点击事件。然后填充Fragment。

Fragment实例化用Fragment自带的静态工程方法newInstance（），便于传值和调用。

Fragment的实现

package com.example.wangchang.segmentcontrol.fragment;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.example.wangchang.segmentcontrol.R;

/** * Created by WangChang on 2016/5/15. */
public class BookFragment extends Fragment {
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_index, container, false);
        return view;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        TextView tv = (TextView) getActivity().findViewById(R.id.tv);
        Bundle bundle = getArguments();
        if (bundle != null) {
            tv.setText(bundle.getString("ARGS"));
        }
    }

    public static BookFragment newInstance(String content) {
        Bundle args = new Bundle();
        args.putString("ARGS", content);
        BookFragment fragment = new BookFragment();
        fragment.setArguments(args);
        return fragment;
    }
}

这里没什么讲的，主要是静态工厂方法newInstance，和利用setArgument传值。

segmentcontrol代码会在项目中给出，这个demo可以直接用于项目中。

下载地址：
http://pan.baidu.com/s/1mietbvi