具体代码如下所示：

//MyCircleView类public class MyCircleView extends View{ //当前画笔画圆的颜色 private int CurrenCircleBoundColor; private Paint paint; ////从xml中获取的颜色 private int circleBundColor; private float circleBoundWidth; private float pivotX; private float pivotY; private float radius=130; private float currentDegree=0; private int currentSpeed=1; private boolean isPause=false; public MyCircleView(Context context) { super(context); initView(context); } public MyCircleView(Context context, @Nullable AttributeSet attrs) { super(context, attrs); initView(context); TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.MyCircleView); for (int i = 0; i < typedArray.getIndexCount(); i++) { //就是我们自定义的属性的资源id int attr = typedArray.getIndex(i); switch (attr){ case R.styleable.MyCircleView_circlr_bound_color: circleBundColor = typedArray.getColor(attr, Color.RED); CurrenCircleBoundColor=circleBundColor; break; case R.styleable.MyCircleView_circlr_bound_width: circleBoundWidth = typedArray.getDimension(attr, 3); break; } } } public MyCircleView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); initView(context); } private void initView(Context context){ paint = new Paint(); } public void setColor(int color){ if (CurrenCircleBoundColor!=color){ CurrenCircleBoundColor=color; }else { CurrenCircleBoundColor=circleBundColor; } } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); paint.setAntiAlias(true); paint.setColor(CurrenCircleBoundColor); paint.setStrokeWidth(circleBoundWidth); paint.setStyle(Paint.Style.STROKE); pivotX = getWidth() / 2; pivotY = getHeight() / 2; canvas.drawCircle(pivotX,pivotY,radius,paint); canvas.save(); //旋转画布 , 如果旋转的的度数大的话,视觉上看着是旋转快的 canvas.rotate(currentDegree,pivotX,pivotY); //提供了一些api可以用来画线(画路径) Path path = new Path(); //从哪开始画 从A开始画 path.moveTo(pivotX+radius,pivotY); //从A点画一个直线到D点 path.lineTo(pivotX+radius-20,pivotY-20); //从D点画一个直线到B点 path.lineTo(pivotX+radius,pivotY+20); //从B点画一个直线到C点 path.lineTo(pivotX+radius+20,pivotY-20); //闭合 -- 从C点画一个直线到A点 path.close(); paint.setStyle(Paint.Style.FILL); paint.setColor(Color.BLACK); canvas.drawPath(path,paint); canvas.restore(); //旋转的度数一个一个度数增加, 如果乘以一个速度的话,按一个速度速度增加 currentDegree+=1*currentSpeed; if (!isPause){ invalidate(); } } public void speed(){ ++currentSpeed; if (currentSpeed>=10){ currentSpeed=10; Toast.makeText(getContext(),"我比闪电还快",Toast.LENGTH_SHORT).show(); } } public void slowDown(){ --currentSpeed; if (currentSpeed<=1){ currentSpeed=1; } } public void pauseOrStart(){ //如果是开始状态的话去重新绘制 if (isPause){ isPause=!isPause; invalidate(); }else { isPause=!isPause; } }}//主页面public class MainActivity extends AppCompatActivity { //全局变量 private MyCircleView my_view; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //找控件 my_view = (MyCircleView) findViewById(R.id.my_view); } public void onClick(View view){ my_view.setColor(Color.BLUE); } public void add(View view){ my_view.speed(); } public void slow(View view){ my_view.slowDown(); } public void pauseOrStart(View view){ my_view.pauseOrStart(); }}主页面布局<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.lx_20170928.MainActivity"> <Button android:id="@+id/set_color_btn" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:onClick="onClick" android:text="设置颜色" /> <Button android:id="@+id/add" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@id/set_color_btn" android:layout_centerHorizontal="true" android:onClick="add" android:text="加速" /> <Button android:id="@+id/slow" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/add" android:layout_centerHorizontal="true" android:onClick="slow" android:text="减速" /> <Button android:id="@+id/pause_or_start" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/slow" android:layout_centerHorizontal="true" android:onClick="pauseOrStart" android:text="暂定/开始" /> <com.example.lx_20170928.MyCircleView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/my_view" android:layout_centerInParent="true" app:circlr_bound_color="@color/colorAccent" app:circlr_bound_width="3dp" /></RelativeLayout>//在values建一个attrs.xml<resources> <declare-styleable name="MyCustomCircleArrowView"> <attr name="circlr_bound_width" format="dimension"></attr> <attr name="circlr_bound_color" format="color"></attr> </declare-styleable></resources>

效果图如下所示：

总结

以上所述是小编给大家介绍的Android自定义View实现箭头沿圆转动实例代码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对网站的支持！