android首字母小写,Android仿微信实现首字母导航条

本文介绍Android实现首字母导航条，先看张效果图，具体怎么实现看代码吧

具体的步骤

1.整体布局的显示

2. 实现A-Z的分组

3. 自定义A-Z的导航条

4. 中间显示/隐藏触摸到导航条具体的字母

activity_main.xml

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:background="#fff"

android:orientation="vertical"

tools:context="com.example.firstnavigation.MainActivity">

android:layout_width="match_parent"

android:layout_height="wrap_content">

android:id="@+id/friend_listview"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_gravity="center" />

android:id="@+id/tv_first"

android:layout_width="80dp"

android:layout_height="80dp"

android:layout_gravity="center"

android:text="A"

android:textColor="#ff0000"

android:textSize="30sp"

android:visibility="gone" />

android:id="@+id/slidView"

android:layout_width="30dp"

android:layout_height="match_parent"

android:layout_gravity="right|center" />

item.xml —-》ListView对应item

android:layout_width="match_parent"

android:layout_height="match_parent"

android:background="#fff"

android:orientation="vertical">

android:id="@+id/tv"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:background="#9e9d9d"

android:textColor="#fff"

android:textSize="16sp" />

android:id="@+id/name"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textColor="#262626"

android:textSize="16sp" />

联系人Bean

public class Contact {

//姓名

private String name;

//姓名的首字母

private String firstWord;

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getFirstWord() {

return firstWord;

}

public void setFirstWord(String ch) {

this.firstWord = ch;

}

}

ContactAdapter.java

public class ContactAdapter extends BaseAdapter {

private ArrayList arrayList;

private Context context;

private String pre = "A";

public ContactAdapter(ArrayList arrayList, Context context) {

this.arrayList = arrayList;

this.context = context;

}

@Override

public int getCount() {

return arrayList.size();

}

@Override

public Object getItem(int position) {

return arrayList.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, parent, false);

viewHolder.tv_firstWord = (TextView) convertView.findViewById(R.id.tv);

viewHolder.name = (TextView) convertView.findViewById(R.id.name);

convertView.setTag(viewHolder);

} else {

viewHolder = (ViewHolder) convertView.getTag();

}

viewHolder.tv_firstWord.setText(String.valueOf(arrayList.get(position).getFirstWord()));

viewHolder.name.setText(arrayList.get(position).getName());

/**

* 分组:根据汉字的首字母

*/

viewHolder.tv_firstWord.setVisibility(!arrayList.get(position).getFirstWord().equals(pre) ? View.VISIBLE : View.GONE);

pre = arrayList.get(position).getFirstWord();

return convertView;

}

class ViewHolder {

TextView tv_firstWord;

TextView name;

}

MainActivity

public class MainActivity extends AppCompatActivity {

private ListView listView;

private TextView tv_first;

private ArrayList contacts;

private SlidView slidView;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

initView();

initData();

}

private void initView() {

listView = (ListView) findViewById(R.id.friend_listview);

tv_first = (TextView) findViewById(R.id.tv_first);

slidView = (SlidView) findViewById(R.id.slidView);

slidView.setFirstListener(new OnTouchFirstListener() {

@Override

public void onTouch(String str) {

tv_first.setVisibility(View.VISIBLE);

tv_first.setText(str);

for (int i = 0; i < contacts.size(); i++) {

if (str.equals(contacts.get(i).getFirstWord())) {

listView.setSelection(i);

}

}

}

@Override

public void onRelease() {

new Handler().postDelayed(new Runnable() {

@Override

public void run() {

tv_first.setVisibility(View.GONE);

}

}, 300);

}

});

}

private void initData() {

contacts = new ArrayList<>();

//获取字符数组资源

String[] attrs = getResources().getStringArray(R.array.myFriend);

Contact contact;

for (int i = 0; i < attrs.length; i++) {

contact = new Contact();

contact.setName(attrs[i]);

contact.setFirstWord(getPinYinHeadChar(attrs[i], 2));

contacts.add(contact);

}

//排序A-Z

Collections.sort(contacts, new Comparator() {

@Override

public int compare(Contact lhs, Contact rhs) {

return lhs.getFirstWord().compareTo(rhs.getFirstWord());

}

});

ContactAdapter contactAdapter = new ContactAdapter(contacts, this);

listView.setAdapter(contactAdapter);

}

/**

* 提取汉字的首字母，如果里面含有费中文字符则忽略之；如果全为非中文则返回""。

*

* @param caseType 当为1时获取的首字母为小写，否则为大写。

*/

public static String getPinYinHeadChar(String zn_str, int caseType) {

if (zn_str != null && !zn_str.trim().equalsIgnoreCase("")) {

char[] strChar = zn_str.toCharArray();

// 汉语拼音格式输出类

HanyuPinyinOutputFormat hanYuPinOutputFormat = new HanyuPinyinOutputFormat();

// 输出设置，大小写，音标方式等

if (1 == caseType) {

hanYuPinOutputFormat.setCaseType(HanyuPinyinCaseType.LOWERCASE);

} else {

hanYuPinOutputFormat.setCaseType(HanyuPinyinCaseType.UPPERCASE);

}

hanYuPinOutputFormat.setToneType(HanyuPinyinToneType.WITHOUT_TONE);

hanYuPinOutputFormat.setVCharType(HanyuPinyinVCharType.WITH_V);

StringBuffer pyStringBuffer = new StringBuffer();

char c = strChar[0];

char pyc;

if (String.valueOf(c).matches("[\\u4E00-\\u9FA5]+")) {//是中文或者a-z或者A-Z转换拼音

try {

String[] pyStirngArray = PinyinHelper.toHanyuPinyinStringArray(strChar[0], hanYuPinOutputFormat);

if (null != pyStirngArray && pyStirngArray[0] != null) {

pyc = pyStirngArray[0].charAt(0);

pyStringBuffer.append(pyc);

}

} catch (BadHanyuPinyinOutputFormatCombination e) {

e.printStackTrace();

}

}

return pyStringBuffer.toString();

}

return null;

}

提取首字母需要用到pingyin4j.jar，小编在这不提供，大家可以在网上下载

//自定义字母导航控件

public class SlidView extends View {

private String[] strs = {"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 Paint paint;

private OnTouchFirstListener listener;

public SlidView(Context context) {

this(context, null);

}

public SlidView(Context context, AttributeSet attrs) {

this(context, attrs, 0);

}

public SlidView(Context context, AttributeSet attrs, int defStyleAttr) {

super(context, attrs, defStyleAttr);

paint = new Paint();

paint.setAntiAlias(true);

paint.setColor(Color.GRAY);

paint.setTypeface(Typeface.DEFAULT_BOLD);

}

// px---->sp

protected int sp2px(int spVal) {

return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, spVal, getResources().getDisplayMetrics());

}

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

for (int i = 0; i < strs.length; i++) {

paint.setColor(i == index ? Color.RED : Color.BLACK);

paint.setTextSize(i == index ? sp2px(18) : sp2px(16));

int x = (int) (getWidth() - paint.measureText(strs[i])) / 2;

int y = getHeight() / strs.length * (i + 1);

canvas.drawText(strs[i], x, y, paint);

}

}

int index = -1; //获取触摸到字母索引的位置

//触碰事件

//按下，松开，拖动

@Override

public boolean onTouchEvent(MotionEvent event) {

switch (event.getAction()) {

case MotionEvent.ACTION_DOWN:

case MotionEvent.ACTION_MOVE:

float y = event.getY();

this.setBackgroundColor(Color.GRAY);

//获取触摸到字母的位置

index = (int) y * strs.length / getHeight();

listener.onTouch(strs[index]);

break;

case MotionEvent.ACTION_UP:

this.setBackgroundColor(android.R.color.transparent);

index = -1;

listener.onRelease();

break;

}

//重绘

invalidate();

return true;

}

public void setFirstListener(OnTouchFirstListener listener) {

this.listener = listener;

}

}

/**

* OnTouchFirstListener 接口

* onTouch：触摸到了那个字母

* onRelease:up释放时中间显示的字母需要设置为GONE

*/

public interface OnTouchFirstListener {

void onTouch(String ch);

void onRelease();

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。