Android-自定义联系人快速索引

效果图：

布局去指定

view.custom.shangguigucustomview.MyCustomIndexView 自定义View对象

<!-- 自定义联系人快速索引 -->
<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"
    android:orientation="vertical"
    tools:context=".ShangGuiguTestActivity">

    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    </ListView>

    <TextView
        android:id="@+id/tv_word"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:background="#22000000"
        android:layout_centerInParent="true"
        android:textSize="40dp"
        android:textColor="@android:color/black"
        android:gravity="center_horizontal|center_vertical"
        android:visibility="gone"
        />

    <view.custom.shangguigucustomview.MyCustomIndexView
        android:id="@+id/mycustom_indexview"
        android:layout_width="30dp"
        android:layout_height="match_parent"
        android:layout_alignParentRight="true"
        android:background="#f00000"
        />

</RelativeLayout>

自定义联系人快速索引处理类：

public class MyCustomIndexView extends View { // 为什么是继承View，因为不需要操纵孩子，只需要操纵TextView

    private static final String TAG = MyCustomIndexView.class.getSimpleName();

    private String[] words = {"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"};

    private IMyCustomIndexBack iBack2;

    public void setBack(IMyCustomIndexBack iBack2) {
        this.iBack2 = iBack2;
    }


    private Paint paint;

    public MyCustomIndexView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);

        paint = new Paint();
        paint.setTextSize(40);
        paint.setAntiAlias(true);
        paint.setTypeface(Typeface.DEFAULT_BOLD);
        paint.setColor(Color.WHITE);
    }

    private int indexViewWidth;
    private int itemIndexViewHeight;

    private int heightMeasureSpec;

    private int itemHeight;

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        itemIndexViewHeight = heightMeasureSpec / words.length;
        indexViewWidth = widthMeasureSpec;

        this.heightMeasureSpec = heightMeasureSpec;

        // setMeasuredDimension(indexViewWidth, indexViewHeight);

        // itemHeight = getMeasuredHeight() / words.length;
        itemHeight = MeasureSpec.getSize(heightMeasureSpec) / words.length;

        Log.i(TAG, "高度实验: getMeasuredHeight():"+getMeasuredHeight() + " heightMeasureSpec:" + heightMeasureSpec);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        int w = MeasureSpec.getSize(indexViewWidth);
        int h = MeasureSpec.getSize(itemIndexViewHeight);
        int defaultH = MeasureSpec.getSize(heightMeasureSpec);

        int defaultH26 = defaultH / words.length;


        for (int i=0; i<words.length;i++) {
            if (wordIndexValue==i) {
                paint.setColor(Color.BLACK);
                paint.setTextSize(50);
            } else {
                paint.setColor(Color.WHITE);
                paint.setTextSize(40);
            }

            String word = words[i];

            // 我要得到字体到宽度
            Rect rect = new Rect();
            // 需要用到画笔 把值处理好传递给Rect
            paint.getTextBounds(word, 0, 1, rect);

            canvas.drawText(word, (w/2) - rect.width()/2, i==0?defaultH26:defaultH26*(i+1), paint);
        }

    }

    private int wordIndexValue = -1;

    private int tempWordIndexValue;

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        super.onTouchEvent(event);
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
            case MotionEvent.ACTION_MOVE:
                /*float endY = event.getY();
                Log.i(TAG, "endy:" + endY);
                // 得到字母索引
                int abcIndex =  (int) (endY / itemIndexViewHeight);
                Log.i(TAG, "abcIndex:" + abcIndex);*/

                float Y = event.getY();
                wordIndexValue = (int) (Y/itemHeight);//字母索引
                Log.i(TAG, "wordIndexValue;" + wordIndexValue);

                if (tempWordIndexValue != wordIndexValue) {
                    iBack2.back(wordIndexValue, words[wordIndexValue]);
                }
                tempWordIndexValue = wordIndexValue;
                invalidate();

                break;
            case MotionEvent.ACTION_UP:
                iBack2.upEnd();

                tempWordIndexValue = 0;

                wordIndexValue = -1;
                invalidate();
                break;
            default:
                break;
        }
        return true;
    }
}

如何使用自定义联系人快速索引：

/**
         * 自定义联系人快速索引
         */
        tv_word = (TextView) findViewById(R.id.tv_word);

        final MyCustomIndexView  myCustomIndexView = findViewById(R.id.mycustom_indexview);
        myCustomIndexView.setBack(new IMyCustomIndexBack() {
            @Override
            public void back(int index, String word) {
                tv_word.setVisibility(View.VISIBLE);
                tv_word.setText(word);
                // Toast.makeText(MainActivity.this, "index:" + index + " word:" + word, Toast.LENGTH_SHORT).show();
            }

            @Override
            public void upEnd() {
                handler.sendEmptyMessageDelayed(0, 0);
            }
        });

/**
     * 自定义联系人快速索引
     */
    private Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            AlphaAnimation alphaAnimation = new AlphaAnimation(1.0f, 0.0f);
            alphaAnimation.setDuration(3000);
            alphaAnimation.setFillAfter(true);

            tv_word.startAnimation(alphaAnimation);
            // tv_word.setVisibility(View.GONE);
        }
    };