前言：消息未读，显示红点或者红色数字，其实就是一个TextView，有推送一般就有badgeView。
Step 1
因为在github上看到了一些类似的第三方库，嫌麻烦，不如直接封装一个类，直接使用。当然这也是在网上找的。代码如下：
public class BadgeView extends AppCompatTextView {
public static final int POSITION_TOP_LEFT = ;
public static final int POSITION_TOP_RIGHT = ;
public static final int POSITION_BOTTOM_LEFT = ;
public static final int POSITION_BOTTOM_RIGHT = ;
public static final int POSITION_CENTER = ;
private static final int DEFAULT_MARGIN_DIP = ;
private static final int DEFAULT_LR_PADDING_DIP = ;
private static final int DEFAULT_CORNER_RADIUS_DIP = ;
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 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, );
}
/**
* Constructor -
*
* create a new BadgeView instance attached to a target {@link 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, );
}
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, , paddingPixels, );
setTextColor(DEFAULT_TEXT_COLOR);
fadeIn = new AlphaAnimation(, );
fadeIn.setInterpolator(new DecelerateInterpolator());
fadeIn.setDuration();
fadeOut = new AlphaAnimation(, );
fadeOut.setInterpolator(new AccelerateInterpolator());
fadeOut.setDuration();
isShown = false;
if (this.target != null) {
applyTo(this.target);
} else {
show();
}
}
private void applyTo(View target) {
ViewGroup.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 ViewGroup.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
this.setVisibility(View.GONE);
container.addView(this);
} else {
// TODO verify that parent is indeed a ViewGroup
ViewGroup group = (ViewGroup) parent;
int index = group.indexOfChild(target);
group.removeView(target);
group.addView(container, index, lp);
container.addView(target);
this.setVisibility(View.GONE);
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) {
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 = ;
}
} else {
i = ;
}
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, , );
break;
case POSITION_TOP_RIGHT:
lp.gravity = Gravity.RIGHT | Gravity.TOP;
lp.setMargins(, badgeMarginV, badgeMarginH, );
break;
case POSITION_BOTTOM_LEFT:
lp.gravity = Gravity.LEFT | Gravity.BOTTOM;
lp.setMargins(badgeMarginH, , , badgeMarginV);
break;
case POSITION_BOTTOM_RIGHT:
lp.gravity = Gravity.RIGHT | Gravity.BOTTOM;
lp.setMargins(, , badgeMarginH, badgeMarginV);
break;
case POSITION_CENTER:
lp.gravity = Gravity.CENTER;
lp.setMargins(, , , );
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;
}
}Step 2
然后就是怎么用了。
有一个Button名字暂且叫做bt
BadgeView badge=BadgeView(context,bt)
badge.setBadgePosition=BadgeView.POSITION_TOP_RIGHT
badge.setText="99+" //这里自己设置显示未读消息的条数
badge.setTextSize=10.0f //这里设置显示数字的大小
badge.setTextColor(Color.WHITE) //这里设置显示的颜色
badge.setVisiblility=View.VISIBLE //这是设置显示或隐藏，默认是显示的
badge.show() //这里就真的show出来了，没有这句话，都是纸上谈兵
Warning
1.需求：如果你想要覆盖之前的消息，就是说你要更新显示的数字，比如原来有99条未读的消息，然后读了一条，需要更新未读数目。
解决方案：如果用多次BadgeView(context,bt)是没有效果的。这里坑了我很久。
你需要判断badge是否为null，如果为null就用BadgeView(context,bt)
如果badge不为null，也就是要更新数字了，直接badge.setText="你要更新的数字即可"
2.需求：如果没有未读的消息了，要去掉badge，怎么办？
解决方案：因为BadgeView就是类似TextView的，所以当没有未读消息，直接隐藏就行了。
badge.setVisibility=View.GONE