android控件上面實現提醒信息

android開發中，經常會用到顯示一個提醒信息，比如個人中心，有新信息，購買商品後，在購物車控件，顯示購物數量等。我們可以用，2個控件來實現，或者用層疊圖。   還有一種簡單方便的辦法，使用別人的開源代碼來實現，使用很簡單方便，通用。 效果圖：   主類：不需要任何改動，直接可以用的。代碼比較多，但是就一個java類，不需要知道它具體怎麼實現，知道怎麼用就行了。直接拷貝該java類到你的項目，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);//創建一個BadgeView對象，view為你需要顯示提醒的控件         badge1.setText("12"); //顯示類容         badge1.setBadgePosition(BadgeView.POSITION_CENTER);//顯示的位置.中間         badge1.setTextColor(Color.WHITE);  //文本顏色         badge1.setBadgeBackgroundColor(Color.RED); //背景顏色         badge1.setTextSize(12); //文本大小         badge1.setBadgeMargin(0, 0); //水平和豎直方向的間距         /**          * 可以設置一個動畫          */ //        TranslateAnimation anim = new TranslateAnimation(-100, 0, 0, 0); //        anim.setInterpolator(new BounceInterpolator()); //        anim.setDuration(1000); //        badge1.toggle(anim,null);         badge1.toggle(); //設置 }   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) {   }   }   xml： <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>