android开发之实现动态打勾效果(DrawHookView)

今天产品中要实现这样的需求，想了想还是把它给整出来了！ 

第一步：自定义View 
实现步骤： 
1、先画好圆弧 
2、再画第一根线 
3、最后再画第二根线

/**
 * DrawHook
 * Created by Zane on 2015/3/4.
 */
public class DrawHookView extends View {
    //绘制圆弧的进度值
    private int progress = 0;
    //线1的x轴
    private int line1_x = 0;
    //线1的y轴
    private int line1_y = 0;
    //线2的x轴
    private int line2_x = 0;
    //线2的y轴
    private int line2_y = 0;

    public DrawHookView(Context context) {
        super(context);
    }

    public DrawHookView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public DrawHookView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    //绘制

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        progress++;

        /**
         * 绘制圆弧
         */
        Paint paint = new Paint();
        //设置画笔颜色
        paint.setColor(getResources().getColor(R.color.arc_blue));
        //设置圆弧的宽度
        paint.setStrokeWidth(5);
        //设置圆弧为空心
        paint.setStyle(Paint.Style.STROKE);
        //消除锯齿
        paint.setAntiAlias(true);

        //获取圆心的x坐标
        int center = getWidth() / 2;
        int center1 = center - getWidth() / 5;
        //圆弧半径
        int radius = getWidth() / 2 - 5;

        //定义的圆弧的形状和大小的界限
        RectF rectF = new RectF(center - radius -1, center - radius -1 ,center + radius + 1, center + radius + 1);

        //根据进度画圆弧
        canvas.drawArc(rectF, 235, -360 * progress / 100, false, paint);

        /**
         * 绘制对勾
         */
        //先等圆弧画完，才话对勾
        if(progress >= 100) {
            if(line1_x < radius / 3) {
                line1_x++;
                line1_y++;
            }
            //画第一根线
            canvas.drawLine(center1, center, center1 + line1_x, center + line1_y, paint);

            if (line1_x == radius / 3) {
                line2_x = line1_x;
                line2_y = line1_y;
                line1_x++;
                line1_y++;
            }
            if (line1_x >= radius / 3 && line2_x <= radius) {
                line2_x++;
                line2_y--;
            }
            //画第二根线
            canvas.drawLine(center1 + line1_x - 1, center + line1_y, center1 + line2_x, center + line2_y, paint);
        }

        //每隔10毫秒界面刷新
        postInvalidateDelayed(10);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:background="@color/color_fff"
        >
    <com.offcn.DrawHookViewDemo.DrawHookView
            android:layout_width="90dp"
            android:layout_height="90dp"
            android:layout_centerInParent="true"
            />
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="arc_blue">#10a679</color>
    <color name="color_fff">#ffffff</color>
</resources>

https://github.com/ZaneLove/DrawHookView