Android自定义加载圈

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.tlkg.welcome.loadingviewdemo.MainActivity">    <com.tlkg.welcome.loadingviewdemo.LoadingView        android:layout_width="150dp"        android:layout_height="150dp"        android:layout_centerInParent="true" /></RelativeLayout>

public class LoadingView extends LinearLayout {    public LoadingView(Context context) {        this(context, null);    }    public LoadingView(Context context, @Nullable AttributeSet attrs) {        this(context, attrs, 0);    }    public LoadingView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        setOrientation(VERTICAL);        setGravity(Gravity.CENTER);        setBackgroundResource(R.drawable.loadingsp);        LoadView loading = new LoadView(getContext());        loading.setLayoutParams(new ViewGroup.LayoutParams(200, 200));        addView(loading);        TextView tv = new TextView(getContext());        tv.setText("正在加载中");        LinearLayout.LayoutParams layoutParams = new LayoutParams(-2, -2);        layoutParams.setMargins(0, 10, 0, 0);        tv.setLayoutParams(layoutParams);        tv.setGravity(Gravity.CENTER);        tv.setTextColor(Color.WHITE);        addView(tv);    }    class LoadView extends View {        Paint mPaint;        private int mWidth;        private int mHeight;        private int mCurrentIndex = 0;        private int count = 12;        public LoadView(Context context) {            super(context);            mPaint = new Paint();            mPaint.setAntiAlias(true);            mPaint.setStyle(Paint.Style.FILL);            mPaint.setStrokeWidth(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 3, getResources().getDisplayMetrics()));            mPaint.setColor(Color.WHITE);        }        @Override        protected void onDraw(Canvas canvas) {            super.onDraw(canvas);            if (mCurrentIndex >= count) {                mCurrentIndex = 0;            }            int endAlpha = 255 / count;            for (int i = 0; i < count; i++) {                int alpha;                if (mCurrentIndex - i > 0) {                    alpha = endAlpha * (mCurrentIndex - i);                } else {                    alpha = 255 - 255 / count * (i - mCurrentIndex);                }                mPaint.setColor(Color.argb(alpha, 255, 255, 255));                canvas.drawLine(mWidth / 2, 0, mWidth / 2, TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 20, getResources().getDisplayMetrics()), mPaint);                canvas.rotate(360 / count, mWidth / 2, mHeight / 2);            }            mCurrentIndex++;            postInvalidateDelayed(100);        }        @Override        protected void onSizeChanged(int w, int h, int oldw, int oldh) {            super.onSizeChanged(w, h, oldw, oldh);            mWidth = getWidth();            mHeight = getHeight();        }    }}

<shape xmlns:android="http://schemas.android.com/apk/res/android">    <corners android:radius="5dp" />    <solid android:color="#aa000000" /></shape>