关于安卓自定义类似于iOS系统自带的菊花loading

app加载数据一般都需要loading加载框，加载框的样式也是千千万万种，根据UI、需求而定，iOS系统自带的菊花loading简洁，也比较常用，下面自定义一个类似于iOS系统自带的菊花loading。

先上效果图：

使用方法

下面是完整代码：

public class LoadingView extends View {public LoadingView(Context context) {super(context);}public LoadingView(Context context, @androidx.annotation.Nullable AttributeSet attrs) {super(context, attrs);init();}public LoadingView(Context context, @androidx.annotation.Nullable AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);init();}private static final String TAG = LoadingView.class.getSimpleName();/*** view宽度*/private int width;/*** view高度*/private int height;/*** 菊花的矩形的宽*/private int widthRect;/*** 菊花的矩形的宽*/private int heightRect;/*** 菊花绘制画笔*/private Paint rectPaint;/*** 循环绘制位置*/private int pos = 0;/*** 菊花矩形*/private Rect rect;/*** 循环颜色*/private String[] color = {"#ffffff","#eeeeee","#dddddd","#cccccc","#bbbbbb", "#aaaaaa"};private void init() {rectPaint = new Paint(Paint.ANTI_ALIAS_FLAG);}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {int widthMode = MeasureSpec.getMode(widthMeasureSpec);int heightMode = MeasureSpec.getMode(heightMeasureSpec);//根据个人习惯设置  这里设置  如果是wrap_content  则设置为宽高200if (widthMode == MeasureSpec.AT_MOST || heightMode == MeasureSpec.AT_MOST) {width = 200;} else {width = MeasureSpec.getSize(widthMeasureSpec);height = MeasureSpec.getSize(heightMeasureSpec);width = Math.min(width, height);}widthRect = width / 12;   //菊花矩形的宽heightRect = 4 * widthRect;  //菊花矩形的高setMeasuredDimension(width, width);}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);//绘制部分是关键了，菊花花瓣矩形有12个，我们不可能去一个一个的算出所有的矩形坐标，我们可以考虑//旋转下面的画布canvas来实现绘制，每次旋转30度//首先定义一个矩形if (rect == null) {rect = new Rect((width - widthRect) / 2, 0, (width + widthRect) / 2, heightRect);}//       0  1  2  3  4  5  6  7  8  9  10  11   i的值// ————————————————————————————————————————————————————————//  0   ‖ 0 | 1 | 2 | 3 | 4 | 5 | 5 | 5 | 5 | 5 | 5 | 5 ‖//  1   ‖ 5 | 0 | 1 | 2 | 3 | 4 | 5 | 5 | 5 | 5 | 5 | 5 ‖//  2   ‖ 5 | 5 | 0 | 1 | 2 | 3 | 4 | 5 | 5 | 5 | 5 | 5 ‖//  3   ‖ 5 | 5 | 5 | 0 | 1 | 2 | 3 | 4 | 5 | 5 | 5 | 5 ‖//  4   ‖ 5 | 5 | 5 | 5 | 0 | 1 | 2 | 3 | 4 | 5 | 5 | 5 ‖//  5   ‖ 5 | 5 | 5 | 5 | 5 | 0 | 1 | 2 | 3 | 4 | 5 | 5 ‖//  6   ‖ 5 | 5 | 5 | 5 | 5 | 5 | 0 | 1 | 2 | 3 | 4 | 5 ‖//  7   ‖ 5 | 5 | 5 | 5 | 5 | 5 | 5 | 0 | 1 | 2 | 3 | 4 ‖//  8   ‖ 4 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 0 | 1 | 2 | 3 ‖//  9   ‖ 3 | 4 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 0 | 1 | 2 ‖//  10   ‖ 2 | 3 | 4 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 0 | 1 ‖//  11   ‖ 1 | 2 | 3 | 4 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 0 ‖//  pos的值for (int i = 0; i < 12; i++) {if (i - pos >= 5) {rectPaint.setColor(Color.parseColor(color[5]));} else if (i - pos >= 0 && i - pos < 5) {rectPaint.setColor(Color.parseColor(color[i - pos]));} else if (i - pos >= -7 && i - pos < 0) {rectPaint.setColor(Color.parseColor(color[5]));} else if (i - pos >= -11 && i - pos < -7) {rectPaint.setColor(Color.parseColor(color[12 + i - pos]));}canvas.drawRect(rect, rectPaint);  //绘制canvas.rotate(30, width / 2, width / 2);    //旋转}pos++;if (pos > 11) {pos = 0;}postInvalidateDelayed(150);  //一个周期用时150}
}