自定义View圆圈箭头_

来源：互联网发布：上汽知乎编辑：程序博客网时间：2024/05/19 01:10

创建自定义View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;            Intent intent = new Intent(getContext(), MovieActivity.class);            getContext().startActivity(intent);            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;        }    }}

MainActivity调用：

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();    }}

布局：

 <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" />    <code.view.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"        />

attrs文件:

<resources>    <declare-styleable name="MyCircleView">        <attr name="circlr_bound_width" format="dimension"></attr>        <attr name="circlr_bound_color" format="color"></attr>    </declare-styleable></resources>

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