仿微信雷達尋好友動畫，雷達好友動畫

仿雷達尋好友動畫，雷達好友動畫

先看看要實現的效果：

這種效果正是類似上雷達尋找好友的動畫，於是解壓看看裡面，發現是用一張圖片做的旋轉動畫，於是乎看看這種特效，可以用畫筆直接畫出來，首先是四個圓，然後中間那部分掃描區便是顏色由透明漸層到淡白。比較簡單。

public class RaderView extends View {    private Paint mPaintCircleLine;//繪製圓邊    private Paint mPaintCircle;    private int width;    private int height;    private Matrix matrix;    private int start;    private Handler handler = new Handler();    private Runnable run = new Runnable() {        @Override        public void run() {            start += 1;            matrix = new Matrix();            matrix.postRotate(start, width / 2, height / 2);            RaderView.this.invalidate();//重新整理重繪            handler.postDelayed(run,30);        }    };    public RaderView(Context context) {        this(context, null);    }    public RaderView(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public RaderView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        initPaint();        //得到當前螢幕的像素寬高        width = context.getResources().getDisplayMetrics().widthPixels;        height = context.getResources().getDisplayMetrics().heightPixels;        matrix = new Matrix();        handler.post(run);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        setMeasuredDimension(width, height);//設定該控制項的寬高為當前螢幕的寬高    }    private void initPaint() {        mPaintCircleLine = new Paint();        mPaintCircleLine.setColor(Color.parseColor("#a2a2a2"));        mPaintCircleLine.setAntiAlias(true);//消除鋸齒        mPaintCircleLine.setStyle(Paint.Style.STROKE);//設定實心        mPaintCircleLine.setStrokeWidth(2);//畫筆寬度        mPaintCircle = new Paint();        mPaintCircle.setColor(Color.parseColor("#99a2a2a2"));        mPaintCircle.setAntiAlias(true);    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        //分別繪製四個圓        canvas.drawCircle(width / 2, height / 2, height / 7, mPaintCircleLine);        canvas.drawCircle(width / 2, height / 2, height / 4, mPaintCircleLine);        canvas.drawCircle(width / 2, height / 2, height / 3, mPaintCircleLine);        canvas.drawCircle(width / 2, height / 2, 3 * height / 7, mPaintCircleLine);        //設定色彩坡形從透明到不透明        Shader shader = new SweepGradient(width / 2, height / 2, Color.TRANSPARENT, Color.parseColor("#50aaaaaa"));        mPaintCircle.setShader(shader);        canvas.concat(matrix);        canvas.drawCircle(width / 2, height / 2, 3 * height / 7, mPaintCircle);    }}

布局檔案：

<FrameLayout 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:background="@mipmap/bg"    tools:context=".MainActivity">    <com.example.raderanim.RaderView        android:layout_width="match_parent"        android:layout_height="match_parent" /></FrameLayout>

這就是整個的動畫效果，可以直接拿來用，加張背景就完全ok了。

著作權聲明：本文為博主原創文章，未經博主允許不得轉載。轉載註明出處：http://blog.csdn.net/u010687392