android 自定义view之简易环形进度条

主要是画笔的使用方法

先看效果图

不多说，看代码

1.自定义属性

attrs.xml

2.activity的布局

3.主体代码部分

/**
 * Created by  lpq
 * 简单环形进度条
 */

public class CircleProgressBar extends View {
    private int max;//最大进度
    private int roundColor;//圈颜色
    private int roundProgressColor;//进度颜色
    private int textColor;//文字颜色
    private float textSize;//文字大小
    private float roundWidth;//圈宽度
    private boolean textShow;//是否显示文字
    private int progress;//当前进度
    private Paint paint;
    public static final int STROKE = 0;
    public static final int FILL = 1;

    public CircleProgressBar(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        paint = new Paint();
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.CustomProgressBar);
        max = typedArray.getInteger(R.styleable.CustomProgressBar_max, 100);
        roundColor = typedArray.getColor(R.styleable.CustomProgressBar_roundColor, Color.RED);
        roundProgressColor = typedArray.getColor(R.styleable.CustomProgressBar_roundProgressColor, Color.BLUE);
        textColor = typedArray.getColor(R.styleable.CustomProgressBar_textColor, Color.GREEN);
        textSize = typedArray.getDimension(R.styleable.CustomProgressBar_textSize, 55);
        roundWidth = typedArray.getDimension(R.styleable.CustomProgressBar_roundWidth, 10);
        textShow = typedArray.getBoolean(R.styleable.CustomProgressBar_textShow, true);
        typedArray.recycle();
    }

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

        //第一步 画圆环
        int cx =getWidth()/2;//中心点x坐标
        int cy = getHeight()/2;//中心点y坐标
        int center = cx / 2;//中心点到最外层距离
        float radius = center - roundWidth / 2;//画笔半径
        paint.setColor(roundColor); //圆形颜色
        /*
        Paint.Style.FILL：填充内部
        Paint.Style.FILL_AND_STROKE  ：填充内部和描边
        Paint.Style.STROKE  ：描边
        */
        paint.setStyle(Paint.Style.STROKE);//描边 空心圆
        paint.setStrokeWidth(roundWidth);//圆环宽度
        paint.setAntiAlias(true);//抗锯齿
        /*
        drawCircle的四个参数
        cx：圆心的x坐标。
        cy：圆心的y坐标。
        radius：圆的半径。
        paint：绘制时所使用的画笔
        */
        canvas.drawCircle(cx, cy, radius, paint);

        //第二步 画进度百分比 也就是中间文字
        paint.setColor(textColor);//文字颜色
        paint.setStrokeWidth(0);//文字笔画宽度
        paint.setTextSize(textSize);//文字大小
        paint.setTypeface(Typeface.DEFAULT_BOLD);//字体

        int percent = (int) (progress / (float) max * 100);
        String strPercent = percent + "%";
        Paint.FontMetricsInt pfm = paint.getFontMetricsInt();//绘制文本对象
        if (percent != 0) {
            canvas.drawText(strPercent, cx - paint.measureText(strPercent) / 2,
                    cy + (pfm.bottom - pfm.top) / 2 - pfm.bottom, paint);
        }


        // 第三步 画圆弧
        RectF oval = new RectF(cx-radius, cy-radius,
                cx + radius, cy + radius);
        paint.setColor(roundProgressColor);
        paint.setStrokeWidth(roundWidth);
        paint.setStyle(Paint.Style.STROKE);
        /*
        setStrokeCap(Paint.Cap cap);
        当画笔样式为STROKE或FILL_OR_STROKE时，设置笔刷的图形样式，
        如圆形样式 Cap.ROUND,或方形样式Cap.SQUARE
        */
        paint.setStrokeCap(Paint.Cap.ROUND);
        canvas.drawArc(oval, 0, 360 * progress / max, false, paint);


    }

    public void setProgress(int progress) {
        if (progress < 0) {
            throw new IllegalArgumentException("进度Progress不能小于0");
        }
        if (progress > max) {
            progress = max;
        }
        if (progress <= max) {
            this.progress = progress;
            postInvalidate();
        }
    }
}

4.用一个线程模拟进度

/**
 * Created by lpq
 */
class CircleProgressBarActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_progress)
        tv_btn?.setOnClickListener {
            Thread(Runnable {
                var progress = 0
                while (progress <= 100) {
                    progress += 2
                    circleProgressBar?.setProgress(progress)
                    try {
                        Thread.sleep(100)
                    } catch (e: InterruptedException) {
                        e.printStackTrace()
                    }
                }
            }).start()
        }
    }
}