（转）在任一View上增加数字文字

自定义一个TextView

package com.jack.viewbadger.view;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Color;
import android.graphics.Typeface;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.RoundRectShape;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.ViewParent;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.DecelerateInterpolator;
import android.widget.FrameLayout;
import android.widget.TabWidget;
import android.widget.TextView;

public class BadgeView extends TextView {

	public static final int POSITION_TOP_LEFT = 1;
	public static final int POSITION_TOP_RIGHT = 2;
	public static final int POSITION_BOTTOM_LEFT = 3;
	public static final int POSITION_BOTTOM_RIGHT = 4;
	public static final int POSITION_CENTER = 5;

	private static final int DEFAULT_MARGIN_DIP = 5;
	private static final int DEFAULT_LR_PADDING_DIP = 5;
	private static final int DEFAULT_CORNER_RADIUS_DIP = 8;
	private static final int DEFAULT_POSITION = POSITION_TOP_RIGHT;
	private static final int DEFAULT_BADGE_COLOR = Color
			.parseColor("#CCFF0000"); // Color.RED;
	private static final int DEFAULT_TEXT_COLOR = Color.WHITE;

	private static Animation fadeIn;
	private static Animation fadeOut;

	private Context context;
	private View target;

	private int badgePosition;
	private int badgeMarginH;
	private int badgeMarginV;
	private int badgeColor;

	private boolean isShown;

	private ShapeDrawable badgeBg;

	private int targetTabIndex;

	public BadgeView(Context context) {
		this(context, (AttributeSet) null, android.R.attr.textViewStyle);
	}

	public BadgeView(Context context, AttributeSet attrs) {
		this(context, attrs, android.R.attr.textViewStyle);
	}

	/**
	 * Constructor -
	 * 
	 * create a new BadgeView instance attached to a target
	 * {@link android.view.View}.
	 * 
	 * @param context
	 *            context for this view.
	 * @param target
	 *            the View to attach the badge to.
	 */
	public BadgeView(Context context, View target) {
		this(context, null, android.R.attr.textViewStyle, target, 0);
	}

	/**
	 * Constructor -
	 * 
	 * create a new BadgeView instance attached to a target
	 * {@link android.widget.TabWidget} tab at a given index.
	 * 
	 * @param context
	 *            context for this view.
	 * @param target
	 *            the TabWidget to attach the badge to.
	 * @param index
	 *            the position of the tab within the target.
	 */
	public BadgeView(Context context, TabWidget target, int index) {
		this(context, null, android.R.attr.textViewStyle, target, index);
	}

	public BadgeView(Context context, AttributeSet attrs, int defStyle) {
		this(context, attrs, defStyle, null, 0);
	}

	public BadgeView(Context context, AttributeSet attrs, int defStyle,
			View target, int tabIndex) {
		super(context, attrs, defStyle);
		init(context, target, tabIndex);
	}

	private void init(Context context, View target, int tabIndex) {

		this.context = context;
		this.target = target;
		this.targetTabIndex = tabIndex;

		// apply defaults
		badgePosition = DEFAULT_POSITION;
		badgeMarginH = dipToPixels(DEFAULT_MARGIN_DIP);
		badgeMarginV = badgeMarginH;
		badgeColor = DEFAULT_BADGE_COLOR;

		setTypeface(Typeface.DEFAULT_BOLD);
		int paddingPixels = dipToPixels(DEFAULT_LR_PADDING_DIP);
		setPadding(paddingPixels, 0, paddingPixels, 0);
		setTextColor(DEFAULT_TEXT_COLOR);

		fadeIn = new AlphaAnimation(0, 1);
		fadeIn.setInterpolator(new DecelerateInterpolator());
		fadeIn.setDuration(200);

		fadeOut = new AlphaAnimation(1, 0);
		fadeOut.setInterpolator(new AccelerateInterpolator());
		fadeOut.setDuration(200);

		isShown = false;

		if (this.target != null) {
			applyTo(this.target);
		} else {
			show();
		}

	}
	
	

	/**
	 * @param target
	 * 原理是先判断目标View是否是普通的View，如果是的话，从父类中删除此组件，用一个FrameLayout替代targetView，再把targetView装进FrameLayout，
	 * 把本TextView也装进FrameLayout,设置textView的FrameLayout属性，从而确定textView的显示位置。
	 */
	private void applyTo(View target) {

		LayoutParams lp = target.getLayoutParams();
		ViewParent parent = target.getParent();
		FrameLayout container = new FrameLayout(context);

		if (target instanceof TabWidget) {
			// set target to the relevant tab child container
			target = ((TabWidget) target).getChildTabViewAt(targetTabIndex);
			this.target = target;
			((ViewGroup) target).addView(container, new LayoutParams(
					LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));

			this.setVisibility(View.GONE);
			container.addView(this);
		} else {
			// verify that parent is indeed a ViewGroup  获得target的布局文件
			ViewGroup group = (ViewGroup) parent;
			int index = group.indexOfChild(target);
			group.removeView(target);
			group.addView(container, index, lp);
			container.addView(target);
			this.setVisibility(View.VISIBLE);
			container.addView(this);
			group.invalidate();
		}
	}

	/**
	 * Make the badge visible in the UI.
	 * 
	 */
	public void show() {
		show(false, null);
	}

	/**
	 * Make the badge visible in the UI.
	 * 
	 * @param animate
	 *            flag to apply the default fade-in animation.
	 */
	public void show(boolean animate) {
		show(animate, fadeIn);
	}

	/**
	 * Make the badge visible in the UI.
	 * 
	 * @param anim
	 *            Animation to apply to the view when made visible.
	 */
	public void show(Animation anim) {
		show(true, anim);
	}

	/**
	 * Make the badge non-visible in the UI.
	 * 
	 */
	public void hide() {
		hide(false, null);
	}

	/**
	 * Make the badge non-visible in the UI.
	 * 
	 * @param animate
	 *            flag to apply the default fade-out animation.
	 */
	public void hide(boolean animate) {
		hide(animate, fadeOut);
	}

	/**
	 * Make the badge non-visible in the UI.
	 * 
	 * @param anim
	 *            Animation to apply to the view when made non-visible.
	 */
	public void hide(Animation anim) {
		hide(true, anim);
	}

	/**
	 * Toggle the badge visibility in the UI.
	 * 
	 */
	public void toggle() {
		toggle(false, null, null);
	}

	/**
	 * Toggle the badge visibility in the UI.
	 * 
	 * @param animate
	 *            flag to apply the default fade-in/out animation.
	 */
	public void toggle(boolean animate) {
		toggle(animate, fadeIn, fadeOut);
	}

	/**
	 * Toggle the badge visibility in the UI.
	 * 
	 * @param animIn
	 *            Animation to apply to the view when made visible.
	 * @param animOut
	 *            Animation to apply to the view when made non-visible.
	 */
	public void toggle(Animation animIn, Animation animOut) {
		toggle(true, animIn, animOut);
	}

	private void show(boolean animate, Animation anim) {
		//设置背景填充
		if (getBackground() == null) {
			if (badgeBg == null) {
				badgeBg = getDefaultBackground();
			}
			setBackgroundDrawable(badgeBg);
		}
		applyLayoutParams();

		if (animate) {
			this.startAnimation(anim);
		}
		this.setVisibility(View.VISIBLE);
		isShown = true;
	}

	private void hide(boolean animate, Animation anim) {
		this.setVisibility(View.GONE);
		if (animate) {
			this.startAnimation(anim);
		}
		isShown = false;
	}

	private void toggle(boolean animate, Animation animIn, Animation animOut) {
		if (isShown) {
			hide(animate && (animOut != null), animOut);
		} else {
			show(animate && (animIn != null), animIn);
		}
	}

	/**
	 * Increment the numeric badge label. If the current badge label cannot be
	 * converted to an integer value, its label will be set to "0".
	 * 
	 * @param offset
	 *            the increment offset.
	 */
	public int increment(int offset) {
		CharSequence txt = getText();
		int i;
		if (txt != null) {
			try {
				i = Integer.parseInt(txt.toString());
			} catch (NumberFormatException e) {
				i = 0;
			}
		} else {
			i = 0;
		}
		i = i + offset;
		setText(String.valueOf(i));
		return i;
	}

	/**
	 * Decrement the numeric badge label. If the current badge label cannot be
	 * converted to an integer value, its label will be set to "0".
	 * 
	 * @param offset
	 *            the decrement offset.
	 */
	public int decrement(int offset) {
		return increment(-offset);
	}

	private ShapeDrawable getDefaultBackground() {

		int r = dipToPixels(DEFAULT_CORNER_RADIUS_DIP);
		float[] outerR = new float[] { r, r, r, r, r, r, r, r };

		RoundRectShape rr = new RoundRectShape(outerR, null, null);
		ShapeDrawable drawable = new ShapeDrawable(rr);
		drawable.getPaint().setColor(badgeColor);

		return drawable;

	}

	private void applyLayoutParams() {

		FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(
				LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

		switch (badgePosition) {
		case POSITION_TOP_LEFT:
			lp.gravity = Gravity.LEFT | Gravity.TOP;
			lp.setMargins(badgeMarginH, badgeMarginV, 0, 0);
			break;
		case POSITION_TOP_RIGHT:
			lp.gravity = Gravity.RIGHT | Gravity.TOP;
			lp.setMargins(0, badgeMarginV, badgeMarginH, 0);
			break;
		case POSITION_BOTTOM_LEFT:
			lp.gravity = Gravity.LEFT | Gravity.BOTTOM;
			lp.setMargins(badgeMarginH, 0, 0, badgeMarginV);
			break;
		case POSITION_BOTTOM_RIGHT:
			lp.gravity = Gravity.RIGHT | Gravity.BOTTOM;
			lp.setMargins(0, 0, badgeMarginH, badgeMarginV);
			break;
		case POSITION_CENTER:
			lp.gravity = Gravity.CENTER;
			lp.setMargins(0, 0, 0, 0);
			break;
		default:
			break;
		}
		setLayoutParams(lp);
	}

	/**
	 * Returns the target View this badge has been attached to.
	 * 
	 */
	public View getTarget() {
		return target;
	}

	/**
	 * Is this badge currently visible in the UI?
	 * 
	 */
	@Override
	public boolean isShown() {
		return isShown;
	}

	/**
	 * Returns the positioning of this badge.
	 * 
	 * one of POSITION_TOP_LEFT, POSITION_TOP_RIGHT, POSITION_BOTTOM_LEFT,
	 * POSITION_BOTTOM_RIGHT, POSTION_CENTER.
	 * 
	 */
	public int getBadgePosition() {
		return badgePosition;
	}

	/**
	 * Set the positioning of this badge.
	 * 
	 * @param layoutPosition
	 *            one of POSITION_TOP_LEFT, POSITION_TOP_RIGHT,
	 *            POSITION_BOTTOM_LEFT, POSITION_BOTTOM_RIGHT, POSTION_CENTER.
	 * 
	 */
	public void setBadgePosition(int layoutPosition) {
		this.badgePosition = layoutPosition;
	}

	/**
	 * Returns the horizontal margin from the target View that is applied to
	 * this badge.
	 * 
	 */
	public int getHorizontalBadgeMargin() {
		return badgeMarginH;
	}

	/**
	 * Returns the vertical margin from the target View that is applied to this
	 * badge.
	 * 
	 */
	public int getVerticalBadgeMargin() {
		return badgeMarginV;
	}

	/**
	 * Set the horizontal/vertical margin from the target View that is applied
	 * to this badge.
	 * 
	 * @param badgeMargin
	 *            the margin in pixels.
	 */
	public void setBadgeMargin(int badgeMargin) {
		this.badgeMarginH = badgeMargin;
		this.badgeMarginV = badgeMargin;
	}

	/**
	 * Set the horizontal/vertical margin from the target View that is applied
	 * to this badge.
	 * 
	 * @param horizontal
	 *            margin in pixels.
	 * @param vertical
	 *            margin in pixels.
	 */
	public void setBadgeMargin(int horizontal, int vertical) {
		this.badgeMarginH = horizontal;
		this.badgeMarginV = vertical;
	}

	/**
	 * Returns the color value of the badge background.
	 * 
	 */
	public int getBadgeBackgroundColor() {
		return badgeColor;
	}

	/**
	 * Set the color value of the badge background.
	 * 
	 * @param badgeColor
	 *            the badge background color.
	 */
	public void setBadgeBackgroundColor(int badgeColor) {
		this.badgeColor = badgeColor;
		badgeBg = getDefaultBackground();
	}

	private int dipToPixels(int dip) {
		Resources r = getResources();
		float px = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dip,
				r.getDisplayMetrics());
		return (int) px;
	}

}

 

调用方法

	// *** default badge ***

		View target = findViewById(R.id.default_target);
		BadgeView badge = new BadgeView(this, target);
		badge.setText("1");
		badge.show();

		// *** set position ***

		btnPosition = (Button) findViewById(R.id.position_target);
		badge1 = new BadgeView(this, btnPosition);
		badge1.setText("12");
		badge1.setBadgePosition(BadgeView.POSITION_CENTER);
		btnPosition.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				badge1.toggle();
			}
		});

		// *** badge/text size & colour ***

		btnColour = (Button) findViewById(R.id.colour_target);
		badge2 = new BadgeView(this, btnColour);
		badge2.setText("New!");
		badge2.setTextColor(Color.BLUE);
		badge2.setBadgeBackgroundColor(Color.YELLOW);
		badge2.setTextSize(12);
		btnColour.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				badge2.toggle();
			}
		});

		// *** default animation ***

		btnAnim1 = (Button) findViewById(R.id.anim1_target);
		badge3 = new BadgeView(this, btnAnim1);
		badge3.setText("84");
		btnAnim1.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				badge3.toggle(true);
			}
		});

		// *** custom animation ***

		btnAnim2 = (Button) findViewById(R.id.anim2_target);
		badge4 = new BadgeView(this, btnAnim2);
		badge4.setText("123");
		badge4.setBadgePosition(BadgeView.POSITION_TOP_LEFT);
		badge4.setBadgeMargin(15, 10);
		badge4.setBadgeBackgroundColor(Color.parseColor("#A4C639"));
		btnAnim2.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				TranslateAnimation anim = new TranslateAnimation(-100, 0, 0, 0);
				anim.setInterpolator(new BounceInterpolator());
				anim.setDuration(1000);
				badge4.toggle(anim, null);
			}
		});

		// *** custom background ***

		btnCustom = (Button) findViewById(R.id.custom_target);
		badge5 = new BadgeView(this, btnCustom);
		badge5.setText("37");
		badge5.setBackgroundResource(R.drawable.badge_ifaux);
		badge5.setTextSize(16);
		btnCustom.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				badge5.toggle(true);
			}
		});