android控件上面实现提醒信息
android开发中，经常会用到显示一个提醒信息，比如个人中心，有新信息，购买商品后，在购物车控件，显示购物数量等。我们可以用，2个控件来实现，或者用层叠图。
还有一种简单方便的办法，使用别人的开源代码来实现，使用很简单方便，通用。
效果图：
主类：不需要任何改动，直接可以用的。代码比较多，但是就一个java类，不需要知道它具体怎么实现，知道怎么用就行了。直接拷贝该java类到你的项目，就行了
package com.hck.badgeview; 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; /** * A simple text label view that can be applied as a "badge" to any given {@link android.view.View}. * This class is intended to be instantiated at runtime rather than included in XML layouts. * * @author Jeff Gilfelt */ 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(); } } 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 { // 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 = 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; } } 使用：
package com.hck.badgeview;
import android.os.Bundle;
import android.view.View;
import android.view.animation.BounceInterpolator;
import android.view.animation.TranslateAnimation;
import android.app.Activity;
import android.graphics.Color;
public class MainActivityextends Activity {
@Override
protectedvoid onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void button1(View view) {
BadgeView badge1 = new BadgeView(this, view);//创建一个BadgeView对象，view为你需要显示提醒的控件
badge1.setText("12"); //显示类容
badge1.setBadgePosition(BadgeView.POSITION_CENTER);//显示的位置.中间
badge1.setTextColor(Color.WHITE); //文本颜色
badge1.setBadgeBackgroundColor(Color.RED); //背景颜色
badge1.setTextSize(12); //文本大小
badge1.setBadgeMargin(0, 0); //水平和竖直方向的间距
/**
* 可以设置一个动画
*/
// TranslateAnimation anim = new TranslateAnimation(-100, 0, 0, 0);
// anim.setInterpolator(new BounceInterpolator());
// anim.setDuration(1000);
// badge1.toggle(anim,null);
badge1.toggle(); //设置
}
public void button2(View view) {
BadgeView badge1 = new BadgeView(this, view);
badge1.setText("你有新消息");
badge1.setBadgePosition(BadgeView.POSITION_TOP_RIGHT);
badge1.setTextColor(Color.RED);
badge1.setBadgeBackgroundColor(Color.YELLOW);
badge1.setTextSize(12);
badge1.toggle();
}
public void button3(View view) {
BadgeView badge1 = new BadgeView(this, view);
badge1.setText("呵呵呵");
badge1.setBadgePosition(BadgeView.POSITION_TOP_LEFT);
badge1.setTextColor(Color.DKGRAY);
badge1.setBadgeBackgroundColor(Color.YELLOW);
badge1.setTextSize(12);
TranslateAnimation anim = new TranslateAnimation(-100, 0, 0, 0);
anim.setInterpolator(new BounceInterpolator());
anim.setDuration(1000);
badge1.toggle(anim,null);
}
public void button4(View view) {
BadgeView badge1 = new BadgeView(this, view);
badge1.setText("你有新消息");
badge1.setBadgeMargin(30, 30);
badge1.setBadgePosition(BadgeView.POSITION_TOP_RIGHT);
badge1.setTextColor(Color.WHITE);
badge1.setBadgeBackgroundColor(Color.RED);
badge1.setTextSize(14);
badge1.toggle();
}
public void button5(View view) {
}
}
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="button1"
android:text="button1"/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="button2"
android:text="button2"/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="button3"
android:text="button3"/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="button4"
android:text="button4"/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="button5"
android:text="button5"/>
</LinearLayout>