android 自定义圆形progressbar,Android-自定义ProgressBar实现圆弧进度条

实现圆弧进度条的自定义ProgressBar，可以使用Canvas和Paint来绘制。

首先，创建一个自定义的ProgressBar类，继承自ProgressBar类，并实现构造方法和onDraw方法：

public class CircleProgressBar extends ProgressBar {

    private Paint paint; // 画笔
    private int roundColor; // 圆环颜色
    private int progressColor; // 进度条颜色
    private int textColor; // 文字颜色
    private float textSize; // 文字大小
    private float roundWidth; // 圆环宽度
    private int max; // 最大进度
    private boolean textIsDisplayable; // 是否显示进度文字
    private int style; // 进度条样式
    public static final int STROKE = 0;
    public static final int FILL = 1;

    public CircleProgressBar(Context context) {
        this(context, null);
    }

    public CircleProgressBar(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

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

        // 获取自定义属性的值
        TypedArray mTypedArray = context.obtainStyledAttributes(attrs, R.styleable.CircleProgressBar);

        roundColor = mTypedArray.getColor(R.styleable.CircleProgressBar_roundColor, Color.RED);
        progressColor = mTypedArray.getColor(R.styleable.CircleProgressBar_progressColor, Color.GREEN);
        textColor = mTypedArray.getColor(R.styleable.CircleProgressBar_textColor, Color.GREEN);
        textSize = mTypedArray.getDimension(R.styleable.CircleProgressBar_textSize, 15);
        roundWidth = mTypedArray.getDimension(R.styleable.CircleProgressBar_roundWidth, 5);
        max = mTypedArray.getInteger(R.styleable.CircleProgressBar_max, 100);
        textIsDisplayable = mTypedArray.getBoolean(R.styleable.CircleProgressBar_textIsDisplayable, true);
        style = mTypedArray.getInt(R.styleable.CircleProgressBar_style, 0);

        mTypedArray.recycle();

        // 初始化画笔
        paint = new Paint();
    }

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

        // 获取圆心坐标和半径
        int centerX = getWidth() / 2;
        int centerY = getHeight() / 2;
        int radius = (int) (centerX - roundWidth / 2);

        // 绘制圆环
        paint.setColor(roundColor);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(roundWidth);
        paint.setAntiAlias(true);
        canvas.drawCircle(centerX, centerY, radius, paint);

        // 绘制进度条
        paint.setStrokeWidth(roundWidth);
        paint.setColor(progressColor);
        RectF oval = new RectF(centerX - radius, centerY - radius, centerX + radius, centerY + radius);
        switch (style) {
            case STROKE:
                paint.setStyle(Paint.Style.STROKE);
                canvas.drawArc(oval, 0, 360 * getProgress() / getMax(), false, paint);
                break;
            case FILL:
                paint.setStyle(Paint.Style.FILL_AND_STROKE);
                if (getProgress() != 0)
                    canvas.drawArc(oval, 0, 360 * getProgress() / getMax(), true, paint);
                break;
        }

        // 绘制文字
        paint.setStrokeWidth(0);
        paint.setColor(textColor);
        paint.setTextSize(textSize);
        paint.setTypeface(Typeface.DEFAULT_BOLD);
        int percent = (int) (((float) getProgress() / (float) getMax()) * 100);
        if (textIsDisplayable && percent >= 0) {
            String text = percent + "%";
            float textWidth = paint.measureText(text);
            canvas.drawText(text, centerX - textWidth / 2, centerY + textSize / 2, paint);
        }
    }

}

在这个类中，我们定义了几个自定义属性，包括圆环颜色、进度条颜色、文字颜色、文字大小、圆环宽度、最大进度、是否显示进度文字、进度条样式等。在构造方法中，我们获取了这些属性的值，并初始化了画笔。在onDraw方法中，我们首先获取了圆心坐标和半径，然后使用画笔绘制了圆环和进度条，最后绘制了进度文字。

接下来，在布局文件中使用这个自定义ProgressBar：

<com.example.circleprogressbar.CircleProgressBar
    android:id="@+id/circle_progressbar"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    app:roundColor="#cccccc"
    app:roundWidth="5dp"
    app:progressColor="#FF4081"
    app:textColor="#FF4081"
    app:textSize="20sp"
    app:textIsDisplayable="true"
    app:style="STROKE" />

最后，在Java代码中设置进度值即可：

CircleProgressBar circleProgressBar = findViewById(R.id.circle_progressbar);
circleProgressBar.setProgress(50); // 设置进度为50%

这样就完成了自定义的圆弧进度条的实现。