【安卓札记】仿乐安全首页动态效果

先看效果：

布局：

<LinearLayout xmlns: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:gravity="center"    tools:context=".MainActivity" >    <FrameLayout        android:layout_width="match_parent"        android:layout_height="match_parent" >        <ImageView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center"            android:src="@drawable/homepage_disk_button_orange_normal" />        <ImageView            android:id="@+id/iv_rotate"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center"            android:src="@drawable/homepage_disk_orange_normal" />        <com.example.view.RadiationView            android:id="@+id/rv"            android:layout_width="250dp"            android:layout_height="250dp"            android:layout_gravity="center" />        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center"            android:text="SB"            android:textColor="#ffffff"            android:textSize="30sp" />    </FrameLayout></LinearLayout>

<?xml version="1.0" encoding="utf-8"?><rotate xmlns:android="http://schemas.android.com/apk/res/android"    android:duration="12000"    android:fromDegrees="0"    android:pivotX="50%"    android:pivotY="50%"    android:startOffset="0"    android:interpolator="@android:anim/linear_interpolator"    android:repeatCount="infinite"    android:repeatMode="restart"    android:toDegrees="360" />

package com.example.view;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.os.Handler;import android.util.AttributeSet;import android.util.Log;import android.view.View;/** * @author Rowandjj * *带辐射效果的view */public class RadiationView extends View{	/**	 *画笔	 */	private Paint mPaint = new Paint();		/**	 *颜色 	 */	private int mColor = 0x3f990e;		/**	 * 透明度	 */	private int mAlpha = 60;		private Handler mHandler = null;		private static final int MESSAGE_DRAW = 0;	private static final String TAG = "RadiationView";		private int width;	private int height;		/**	 * 扩散速度	 */	private int speed = 30;	/**	 *最大辐射半径 	 */	private int maxRadius = 100;			private int centerX;	private int centerY;		/**	 * 最小半径	 */	private int minRadius = 70;	/**	 * 当前半径	 */	private int radius = minRadius;		private boolean isStarted = false;		public RadiationView(Context context)	{		super(context);		init();	}	public RadiationView(Context context, AttributeSet attrs)	{		super(context, attrs, 0);		init();	}	public void startRadiate()	{		isStarted = true;		mHandler.sendEmptyMessage(MESSAGE_DRAW);	}		private void init()	{		mPaint = new Paint();		mPaint.setStrokeWidth(1);		//必须先设置color，再设置alpha		mPaint.setColor(mColor);		mPaint.setAlpha(mAlpha);				mHandler = new Handler()		{			public void handleMessage(android.os.Message msg) 			{				if(msg.what == MESSAGE_DRAW)				{					invalidate();					if(isStarted)					{						sendEmptyMessageDelayed(MESSAGE_DRAW,speed);					}				}			}		};	}		@Override	protected void onLayout(boolean changed, int left, int top, int right,			int bottom)	{		super.onLayout(changed, left, top, right, bottom);		width = this.getWidth();		height = this.getHeight();		if(width <= 0 || height<=0)		{			throw new RuntimeException("size illegal");		}		//中心点		centerX = width/2;	    centerY = height/2;		//最大辐射半径		maxRadius = (width > height) ? height/2 : width/2;		Log.i(TAG,"MAX"+maxRadius);		if(maxRadius < 70)		{			throw new RuntimeException("size too small");		}	}	@Override	protected void onDraw(Canvas canvas)	{		mPaint.setColor(mColor);		mPaint.setAlpha(mAlpha);		if(radius <= 0)		{			return;		}		if(radius > maxRadius)		{			radius = minRadius;		}		canvas.save();		canvas.drawCircle(centerX, centerY, radius, mPaint);		canvas.restore();		radius += 1;	}	@Override	protected void onAttachedToWindow()	{		super.onAttachedToWindow();		this.setLayerType(View.LAYER_TYPE_SOFTWARE, null);	}		public void setColor(int color)	{		this.mColor = color;	}		public void setSpeed(int speed)	{		this.speed = speed;	}		public void setMinRadius(int radius)	{		this.minRadius = radius;	}}

package com.example.animdemo1;import android.app.Activity;import android.os.Bundle;import android.view.animation.Animation;import android.view.animation.AnimationUtils;import android.widget.ImageView;import com.example.view.RadiationView;public class MainActivity extends Activity{	private ImageView iv = null;	private RadiationView rv = null;	@Override	protected void onCreate(Bundle savedInstanceState)	{		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_main);				iv = (ImageView) findViewById(R.id.iv_rotate);		rv = (RadiationView) findViewById(R.id.rv);		rv.setMinRadius(70);//辐射半径		rv.startRadiate();//开始辐射		Animation anim = AnimationUtils.loadAnimation(this, R.anim.rotate_circle_anim);		iv.startAnimation(anim);//开始动画	}}