在Android项目中实现底部菜单栏的方法

<com.landptf.view.MenuM
  android:id="@+id/mm_bottom"
  android:layout_width="match_parent"
  android:layout_height="56dp"
  android:layout_alignParentBottom="true"
  landptf:backColor="@color/content"
  landptf:textColor="@color/text"
  landptf:textColorPress="@color/colorPrimary"
  landptf:count="4"
  />

final MenuM mmBottom = (MenuM) findViewById(R.id.mm_bottom);
mmBottom.setText(text);
mmBottom.setIconDrawable(iconDrawable);
mmBottom.setIconDrawablePress(iconDrawablePress);
//设置默认选中第一项
mmBottom.setPressState(0, MotionEvent.ACTION_DOWN);
mmBottom.setOnItemClickListener(new MenuM.OnItemClickListener() {
  @Override
  public void onItemClick(int position) {
    Toast.makeText(MenuMTestActivity.this, mmBottom.getText(position), Toast.LENGTH_SHORT).show();
  }
});

mmBottom.setUnReadCount(0, 100);
mmBottom.setUnReadCount(1, 15);
mmBottom.setVisibilityMore(2, View.VISIBLE);
mmBottom.setVisibilityNew(3, View.VISIBLE);

text = new String[]{"首页", "通讯录", "发现", "我"};
//为了演示方便我只找了两张icon，在实际开发中一般需要从网络上下载，然后在设置
Drawable drawable = getResources().getDrawable(R.drawable.icon_home_page);
Drawable drawablePress = getResources().getDrawable(R.drawable.icon_home_page_press);
iconDrawable = new Drawable[]{drawable, drawable, drawable, drawable};
iconDrawablePress = new Drawable[]{drawablePress, drawablePress, drawablePress, drawablePress};

package com.landptf.view;

import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.TypedArray;
import android.graphics.drawable.Drawable;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;

import com.landptf.R;

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

/**
 * Created by landptf on 2017/01/15.
 * 菜单，可用于底部导航菜单，以及内容区的菜单列表
 */
public class MenuM extends LinearLayout {
  private static final String TAG = MenuM.class.getSimpleName();

  private Context mContext;
  private List<MenuItemM> menuList;
  private List<RelativeLayout> rlList;
  private OnItemClickListener mOnItemClickListener;
  private int count = 0;

  public MenuM(Context context) {
    this(context, null, 0);
  }

  public MenuM(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
  }

  public MenuM(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    mContext = context;
    init(attrs, defStyle);
  }

  private void init(AttributeSet attrs, int defStyle) {
    setOrientation(LinearLayout.HORIZONTAL);
    TypedArray a = mContext.obtainStyledAttributes(attrs, R.styleable.menuM, defStyle, 0);
    if (a != null) {
      //初始化菜单数量
      count = a.getInteger(R.styleable.menuM_count, 0);
      if (count > 0) {
        initControl();
      }
      //设置背景色
      ColorStateList colorList = a.getColorStateList(R.styleable.menuM_backColor);
      if (colorList != null) {
        int backColor = colorList.getColorForState(getDrawableState(), 0);
        if (backColor != 0) {
          setBackColor(backColor);
        }
      }
      //设置文字的颜色
      ColorStateList textColorList = a.getColorStateList(R.styleable.menuM_textColor);
      if (textColorList != null) {
        int textColor = textColorList.getColorForState(getDrawableState(), 0);
        if (textColor != 0) {
          setTextColor(textColor);
        }
      }
      //记录View被按下时文字的颜色
      ColorStateList textColorPressList = a.getColorStateList(R.styleable.menuM_textColorPress);
      if (textColorPressList != null) {
        int textColorPress = textColorPressList.getColorForState(getDrawableState(), 0);
        if (textColorPress != 0) {
          setTextColorPress(textColorPress);
        }
      }
      //设置文本字体大小
      float textSize = a.getFloat(R.styleable.menuM_textSize, 0);
      if (textSize != 0) {
        setTextSize(textSize);
      }
      a.recycle();
    }
  }

  /**
   * 由于MenuItemM是有ButtonExtendM扩展而来，为了适应上下左右不同的样式
   * 需要在MenuItemM外层嵌套一层RelativeLayout，暂时没有找到更好的替代方案
   */
  private void initControl() {
    rlList = new ArrayList<>(count);
    menuList = new ArrayList<>(count);
    for (int i = 0; i < count; i++) {
      RelativeLayout rlPanel = new RelativeLayout(mContext);
      LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.MATCH_PARENT);
      lp.weight = 1;
      rlPanel.setLayoutParams(lp);
      final MenuItemM menuItem = new MenuItemM(mContext);
      RelativeLayout.LayoutParams lpR = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
      lpR.addRule(RelativeLayout.CENTER_IN_PARENT);
      menuItem.setLayoutParams(lpR);
      menuItem.setOnClickListener(new MenuItemM.OnClickListener() {
        @Override
        public void onClick(View v) {
          //此处需要根据view获取position
          MenuM.this.onClick(getPosition(menuItem));
        }
      });
      rlPanel.addView(menuItem);
      menuList.add(menuItem);
      rlList.add(rlPanel);
      addView(rlPanel);
    }
  }

  /**
   * 设置View的背景色
   *
   * @param backColor
   */
  public void setBackColor(int backColor) {
    if (backColor == 0) return;
    if (!checkCount()) {
      return;
    }
    for (RelativeLayout item : rlList) {
      item.setBackgroundColor(backColor);
    }
    for (MenuItemM item : menuList) {
      item.setBackColor(backColor);
    }
  }

  /**
   * 设置文字的颜色
   *
   * @param textColor
   */
  public void setTextColor(int textColor) {
    if (textColor == 0) return;
    if (!checkCount()) {
      return;
    }
    for (MenuItemM item : menuList) {
      item.setTextColor(textColor);
    }
  }

  /**
   * 设置View被按下时文字的颜色
   *
   * @param textColorPress
   */
  public void setTextColorPress(int textColorPress) {
    if (textColorPress == 0) return;
    if (!checkCount()) {
      return;
    }
    for (MenuItemM item : menuList) {
      item.setTextColorPress(textColorPress);
    }
  }

  /**
   * 设置icon的图片
   *
   * @param iconDrawable
   */
  public void setIconDrawable(Drawable[] iconDrawable) {
    if (count != iconDrawable.length) {
      Log.e(TAG, "the iconDrawable length do not equals count");
      return;
    }
    for (int i = 0; i < count; i++) {
      if (iconDrawable[i] != null) {
        menuList.get(i).setIconDrawable(iconDrawable[i]);
      }
    }
  }

  /**
   * 设置icon的图片
   *
   * @param iconDrawable
   */
  public void setIconDrawable(List<Drawable> iconDrawable) {
    if (count != iconDrawable.size()) {
      Log.e(TAG, "the iconDrawable length do not equals count");
      return;
    }
    for (int i = 0; i < count; i++) {
      if (iconDrawable.get(i) != null) {
        menuList.get(i).setIconDrawable(iconDrawable.get(i));
      }
    }
  }

  /**
   * 设置View被按下时的icon的图片
   *
   * @param iconDrawablePress
   */
  public void setIconDrawablePress(Drawable[] iconDrawablePress) {
    if (count != iconDrawablePress.length) {
      Log.e(TAG, "the iconDrawablePress length do not equals count");
      return;
    }
    for (int i = 0; i < count; i++) {
      if (iconDrawablePress[i] != null) {
        menuList.get(i).setIconDrawablePress(iconDrawablePress[i]);
      }
    }
  }

  /**
   * 设置View被按下时的icon的图片
   *
   * @param iconDrawablePress
   */
  public void setIconDrawablePress(List<Drawable> iconDrawablePress) {
    if (count != iconDrawablePress.size()) {
      Log.e(TAG, "the iconDrawablePress length do not equals count");
      return;
    }
    for (int i = 0; i < count; i++) {
      if (iconDrawablePress.get(i) != null) {
        menuList.get(i).setIconDrawablePress(iconDrawablePress.get(i));
      }
    }
  }

  /**
   * 设置显示的文本内容
   *
   * @param text
   */
  public void setText(CharSequence[] text) {
    for (int i = 0; i < count; i++) {
      menuList.get(i).setText(text[i]);
    }
  }

  /**
   * 设置显示的文本内容
   *
   * @param text
   */
  public void setText(List<CharSequence> text) {
    if (count != text.size()) {
      Log.e(TAG, "the text length do not equals count");
      return;
    }
    for (int i = 0; i < count; i++) {
      menuList.get(i).setText(text.get(i));
    }
  }

  /**
   * 获取显示的文本
   *
   * @return
   */
  public String getText(int index) {
    if (!checkIndex(index)) {
      return "";
    }
    return menuList.get(index).getText();
  }

  /**
   * 设置文本字体大小
   *
   * @param size
   */
  public void setTextSize(float size) {
    if (!checkCount()) {
      return;
    }
    for (MenuItemM item : menuList) {
      item.setTextSize(size);
    }
  }

  /**
   * 设置更多提示是否显示
   * 如果显示则先重置new和未读数量图标
   *
   * @param visibleMore
   */
  public void setVisibilityMore(int index, int visibleMore) {
    if (!checkIndex(index)) {
      return;
    }
    menuList.get(index).setVisibilityMore(visibleMore);
  }

  /**
   * 设置New提示是否显示
   * 如果显示则先重置更多和未读数量图标
   *
   * @param visibleNew
   */
  public void setVisibilityNew(int index, int visibleNew) {
    if (!checkIndex(index)) {
      return;
    }
    menuList.get(index).setVisibilityNew(visibleNew);
  }

  /**
   * 设置未读数量
   * 如果小于等于0，表示隐藏
   * 如果大于99，则将其隐藏，同时显示更多的提示
   * 如果在0-99区间，则隐藏更多和new图标
   *
   * @param unReadCount
   */
  public void setUnReadCount(int index, int unReadCount) {
    if (!checkIndex(index)) {
      return;
    }
    menuList.get(index).setUnReadCount(unReadCount);
  }

  /**
   * 设置为被选中状态
   *
   * @param index
   * @param state in MotionEvent.ACTION_DOWN or MotionEvent.ACTION_UP
   */
  public void setPressState(int index, int state) {
    if (!checkIndex(index)) {
      return;
    }
    menuList.get(index).setPressState(state);
  }

  /**
   * 设置菜单点击事件
   *
   * @param listener
   */
  public void setOnItemClickListener(@Nullable OnItemClickListener listener) {
    mOnItemClickListener = listener;
  }

  private void onClick(int position) {
    for (int i = 0; i < count; i++) {
      if (i == position) {
        setPressState(i, MotionEvent.ACTION_DOWN);
      } else {
        setPressState(i, MotionEvent.ACTION_UP);
      }
    }
    mOnItemClickListener.onItemClick(position);
  }

  /**
   * 获取点击菜单项的位置
   * @param item
   * @return
   */
  private int getPosition(MenuItemM item) {
    for (int i = 0; i < count; i++) {
      if (item == menuList.get(i)) {
        return i;
      }
    }
    return -1;
  }

  /**
   * 检查是否设置了Count参数
   *
   * @return
   */
  private boolean checkCount() {
    if (count == 0) {
      Log.e(TAG, "You must set the count first");
      return false;
    }
    return true;
  }

  /**
   * 校验输入参数是否合法
   *
   * @param index
   * @return
   */
  private boolean checkIndex(int index) {
    if (!checkCount()) {
      return false;
    }
    if (index < 0 || index >= count) {
      Log.e(TAG, "the index is wrong");
      return false;
    }
    return true;
  }

  public interface OnItemClickListener {
    void onItemClick(int position);
  }
}