先给大家展示下效果图：
实现代码如下：
下面简单说下实现原理。
public class IndexBar extends LinearLayout implements View.OnTouchListener { private static final String[] INDEXES = 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"}; private static final int TOUCHED_BACKGROUND_COLOR = 0x40000000; private OnIndexChangedListener mListener; public void setOnIndexChangedListener(OnIndexChangedListener listener) { mListener = listener; } public IndexBar(Context context) { this(context, null); } public IndexBar(Context context, AttributeSet attrs) { this(context, attrs, 0); } public IndexBar(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(attrs); } private void init(AttributeSet attrs) { TypedArray ta = getContext().obtainStyledAttributes(attrs, R.styleable.IndexBar); float indexTextSize = ta.getDimension(R.styleable.IndexBar_indexTextSize, Utils.sp2px(getContext(), 12)); int indexTextColor = ta.getColor(R.styleable.IndexBar_indexTextColor, 0xFF616161); ta.recycle(); setOrientation(VERTICAL); setOnTouchListener(this); for (String index : INDEXES) { TextView text = new TextView(getContext()); text.setText(index); text.setTextSize(TypedValue.COMPLEX_UNIT_PX, indexTextSize); text.setTextColor(indexTextColor); text.setGravity(Gravity.CENTER); LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 0, 1); text.setLayoutParams(params); addView(text); } } @Override public boolean onTouch(View v, MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_DOWN: setBackgroundColor(TOUCHED_BACKGROUND_COLOR); handle(v, event); return true; case MotionEvent.ACTION_MOVE: handle(v, event); return true; case MotionEvent.ACTION_UP: setBackgroundColor(Color.TRANSPARENT); handle(v, event); return true; } return super.onTouchEvent(event); } private void handle(View v, MotionEvent event) { int y = (int) event.getY(); int height = v.getHeight(); int position = INDEXES.length * y / height; if (position < 0) { position = 0; } else if (position >= INDEXES.length) { position = INDEXES.length - 1; } String index = INDEXES[position]; boolean showIndicator = event.getAction() != MotionEvent.ACTION_UP; if (mListener != null) { mListener.onIndexChanged(index, showIndicator); } } public interface OnIndexChangedListener { void onIndexChanged(String index, boolean showIndicator); } }
使用
public class CompanyActivity extends BaseActivity implements IndexBar.OnIndexChangedListener { @Bind(R.id.lv_company) ListView lvCompany; @Bind(R.id.ib_indicator) IndexBar ibIndicator; @Bind(R.id.tv_indicator) TextView tvIndicator; private List<CompanyEntity> mCompanyList = new ArrayList<>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_company); // ... } @Override public void onIndexChanged(String index, boolean showIndicator) { int position = -1; for (CompanyEntity company : mCompanyList) { if (TextUtils.equals(company.getName(), index)) { position = mCompanyList.indexOf(company); break; } } if (position != -1) { lvCompany.setSelection(position); } tvIndicator.setText(index); tvIndicator.setVisibility(showIndicator ? View.VISIBLE : View.GONE); } }
继承自LinearLayout，添加了26个字母索引TextView，当手指滑动时通知Activity更新界面。
核心是OnTouchListener，手指滑动的时候根据当前Y坐标计算出手指所在的索引位置，要注意临界值。
以上所述是小编给大家介绍的Android仿微信通讯录滑动快速定位功能，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对脚本之家网站的支持！