学习篇---自定义SiderBar

写了个SiderBar，可以通过点击上面的字母实现对listview的快速定位，简单的写下对listview填充的数据，从A--Z排序

效果图：

SiderBar.java

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ListView;
import android.widget.TextView;

/**
 * Created by Administrator on 2016/5/4.
 */
public class SiderBar extends View {
    private Paint paint;
    private MyAdapter myAdapter;
    private TextView textView;
    private ListView listView;
    private String alphabet[];//26个字母


    public SiderBar(Context context) {
        this(context, null);
    }

    public void setListViewAndAdpter(ListView listView, MyAdapter myAdapter) {
        this.listView = listView;
        this.myAdapter = myAdapter;
    }

    public SiderBar(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public void setTextViewDialog(TextView textViewDialog) {
        this.textView = textViewDialog;

    }

    public void init() {
        alphabet = new String[]{"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T",
                "U", "V", "W", "X", "Y", "Z"};
        //画笔的初始化
        paint = new Paint();
        paint.setAntiAlias(true);
        paint.setFakeBoldText(true);
        paint.setTextSize(23f);
        paint.setColor(Color.parseColor("#000000"));

    }

    /**
     * 绘制26个字母
     * @param canvas
     */
    @Override
    protected void onDraw(Canvas canvas) {
        float letterHeight = (getHeight() - 5) / alphabet.length * 1.0f;
        for (int i = 0; i < alphabet.length; i++) {
            float x = getWidth() / 2 - paint.measureText(alphabet[i]) / 2;
            canvas.drawText(alphabet[i], x, letterHeight * (i + 1), paint);
        }
        super.onDraw(canvas);
    }


    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_UP:
                if (textView != null)//屏幕中间呈现出一个textview
                    textView.setVisibility(INVISIBLE);
                setBackgroundResource(android.R.color.transparent);//抬起使siderbar背景透明
                invalidate();
                break;
            default:
                setBackgroundResource(R.drawable.backgroud_drawable);//按下或移动时使siderbar背景变色
                invalidate();
                float touchY = event.getY();
                int index = (int) (touchY / getHeight() * alphabet.length);//根据点击的y坐标获得点击字母的数组下标
                if (index < alphabet.length && index >= 0) {
                    String currentLetter = alphabet[index];
                    findTouchLetter(currentLetter);
                    if (textView.getVisibility() == INVISIBLE)
                        textView.setVisibility(VISIBLE);
                    textView.setText(currentLetter);
                }
                break;

        }
        return true;

    }
//根据点击的字母让listview定位到相应的位置
    public void findTouchLetter(String letter) {
        for (int i = 0; i < listView.getCount(); i++) {
            if (letter == myAdapter.getItem(i)) {
                listView.setSelection(i);
            }
        }

    }


}

MyAdapter.java

import android.content.Context;
import android.graphics.Color;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.List;

/**
 * Created by Administrator on 2016/5/4.
 */
public class MyAdapter extends BaseAdapter {

    private List list;
    private Context context;

    public MyAdapter(List list, Context context) {
        this.list = list;
        this.context = context;

    }

    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int position) {
        return list.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }


    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        if (convertView == null) {
            viewHolder = new ViewHolder();
            convertView = LayoutInflater.from(context).inflate(R.layout.item_view, null);
            viewHolder.textView = (TextView) convertView.findViewById(R.id.itemTextView);
            convertView.setTag(viewHolder);

        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }
        for (char i = 'A'; i <= 'Z'; i++) {
            if (list.get(position).equals(i + "") || list.get(position).equals("#")) {
                convertView.setBackgroundColor(Color.parseColor("#f1f1fa"));
                break;
            } else {
                convertView.setBackgroundColor(Color.parseColor("#ffffff"));
            }
        }
        viewHolder.textView.setText(list.get(position));

        return convertView;
    }

    class ViewHolder {
        TextView textView;
    }

}

需要用到pinyin4j.jar第三方库，应下载并导入工程;

MainActivity.java

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ListView;
import android.widget.TextView;

import net.sourceforge.pinyin4j.PinyinHelper;
import net.sourceforge.pinyin4j.format.HanyuPinyinCaseType;
import net.sourceforge.pinyin4j.format.HanyuPinyinOutputFormat;
import net.sourceforge.pinyin4j.format.HanyuPinyinToneType;
import net.sourceforge.pinyin4j.format.exception.BadHanyuPinyinOutputFormatCombination;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private TextView textView;
    private SiderBar siderBar;
    private MyAdapter myAdapter;
    private List list;
    private ListView listView;
    private String letter[];

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        listView = (ListView) findViewById(R.id.listView);
        textView = (TextView) findViewById(R.id.textView);
        siderBar = (SiderBar) findViewById(R.id.SiderBar);
        list = new ArrayList();
        letter= new String[]{ "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T",
                "U", "V", "W", "X", "Y", "Z"};
        for (int i = 0; i < letter.length; i++) {
            list.add(letter[i]);
        }
        list.add("Apple");
        list.add("book");
        list.add("要看");
        list.add("原为白色，我需");
        list.add("个item还");
        list.add("码，别");
        list.add("看代");
        list.add("需要");
        list.add("码，别");
        list.add("看代");
        list.add("需要");
        list.add("需要");
        list.add("白色，我");
        list.add("还原为");
        list.add("个item");
        list.add("需要");
        list.add("白色，我");
        list.add("还原为");
        list.add("个item");
        list.add("重写");
        list.add("说什么");
        list.add("码，别");
        list.add("看代");
        list.add("需要");
        list.add("需要");
        list.add("白色，我");
        list.add("还原为");
        list.add("个item");
        list.add("将那");
        list.add("榜，则");
        list.add("十名内出现，则改变那个item");
        list.add("果出");
        list.add("的颜色，");
        list.add("如");

       list = dealList(list);
        myAdapter = new MyAdapter(list, this);

        listView.setAdapter(myAdapter);
        listView.setVerticalScrollBarEnabled(false);//listview滚动条隐藏

        siderBar.setTextViewDialog(textView);//传入textview
        siderBar.setListViewAndAdpter(listView, myAdapter);//传入listview和myAdapter

    }


    /**
     * 获取汉字串拼音首字母，英文字符不变
     *
     * @param chinese
     * @return
     */
    public String cn2FirstSpell(String chinese) {
        StringBuffer pybf = new StringBuffer();
        char[] arr = chinese.toCharArray();
        HanyuPinyinOutputFormat defaultFormat = new HanyuPinyinOutputFormat();
        defaultFormat.setCaseType(HanyuPinyinCaseType.UPPERCASE);
        defaultFormat.setToneType(HanyuPinyinToneType.WITHOUT_TONE);
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] > 128) {
                try {
                    String[] _t = PinyinHelper.toHanyuPinyinStringArray(arr[i], defaultFormat);
                    if (_t != null) {
                        pybf.append(_t[0].charAt(0));
                    }
                } catch (BadHanyuPinyinOutputFormatCombination e) {
                    return "";
                }
            } else {
                pybf.append(arr[i]);
            }
        }
        return pybf.toString().replaceAll("\\W", "").trim();
    }

    /**
     * 获取第一个拼音字母
     *
     * @param string
     * @return
     */
    public String getFirstEnglishLetter(String string) {
        String str = cn2FirstSpell(string);
        String firstLetter=str.charAt(0)+"";

        return firstLetter;

    }

    /**
     * 对给定的list进行A-Z的排序
     *
     * @param list
     * @return
     */

    public List dealList(List list) {
        List afterList = new ArrayList();
        for (char i = 'A'; i <= 'Z'; i++) {
            for (int j = 0; j < list.size(); j++) {
                if ((getFirstEnglishLetter(list.get(j)).toUpperCase()).equals(i + "")) {
                    afterList.add(list.get(j));
                }

            }
        }
        return afterList;


    }
}

activity_main.xml

backgroud_drawable.xml

textview_drawable.xml

源代码下载