我想为Android创建进度条。我的方形进度条有四个图像。

我正在使用android定义的进度栏:

<ProgressBar
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     style="@android:style/Widget.ProgressBar.Small"
     android:layout_marginRight="5dp" />

但是,如果我要制作一个正方形而不是圆形,该怎么办?如何将我的4张图像传递到进度条?

例:

java - 修改进度条的资源图像-LMLPHP

最佳答案

通常,您确实有2个选择:

1.如前所述,使用animation-list并交换图片。

这可能是更简单的解决方案,因为可以使用AnimationDrawable相对容易地对它们进行动画处理。唯一的缺点是,给定结果至少需要16张图像(所有分辨率)。

2.使用自定义绘图。

这是更复杂的方法。您将必须自己绘制图纸并设置动画效果,这对于大多数人来说,几乎没有很好的文档记录就很难了。

因此,您必须extends Drawable implements Runnable, Animatable并提供一些良好的实现。

以下是基本的实现,首先计算位置,然后绘制位置。动画(各个圆圈的大小)可以并且应该进一步调整;)

产生3个变体:
java - 修改进度条的资源图像-LMLPHP

public class RectProgressDrawable extends Drawable implements Runnable, Animatable {
    private static final long FRAME_DELAY = 1000 / 60;
    private static final String TAG = "RectProgressDrawable";
    private boolean mRunning = false;
    private long mStartTime;
    private int mDuration = 1000;

    private Paint mPaint;

    private float[] posX;
    private float[] posY;
    private float mSize;
    private int mPoints = 5;

    /**
     * The padding in px.
     */
    private int mPadding = 4;
    private int mAnimatedPoints = 5;

    public void setPoints(int points) {
        if (points != mPoints) {
            mPoints = points;
            init();
        }
    }

    private void init() {
        if (mPaint == null) {
            mPaint = new Paint();
            mPaint.setColor(Color.WHITE);
            mPaint.setAntiAlias(true);
            mPaint.setStyle(Paint.Style.FILL);
        }

        posX = new float[(mPoints - 1) * 4];
        posY = new float[(mPoints - 1) * 4];

        Rect bounds = new Rect();
        bounds.set(getBounds());
        bounds.inset(mPadding, mPadding);

        float cellWidth = ((float) bounds.width()) / ((float) mPoints);
        float cellHeight = ((float) bounds.height()) / ((float) mPoints);

        float min = Math.min(cellWidth, cellHeight);
        mSize = min / (mPoints - 1);

        for (int i = 0; i < mPoints; i++) { // top row
            posX[i] = bounds.left + cellWidth * (float) i + cellWidth / 2;
            posY[i] = bounds.top + cellHeight / 2;
        }
        for (int i = 0; i < mPoints - 2; i++) { // sides
            // right side top bottom
            posX[mPoints + i] = bounds.left + cellWidth * (mPoints - 1) + cellWidth / 2;
            posY[mPoints + i] = bounds.top + cellHeight * (i + 1) + cellHeight / 2;
            //left side bottom top
            posX[3 * mPoints - 2 + i] = bounds.left + cellWidth / 2;
            posY[3 * mPoints - 2 + i] = bounds.top + cellHeight * (mPoints - 2 - i) + cellHeight / 2;
        }
        for (int i = 0; i < mPoints; i++) { // bottom from right to left
            posX[2 * mPoints - 2 + i] = bounds.left + cellWidth * (mPoints - 1 - i) + cellWidth / 2;
            posY[2 * mPoints - 2 + i] = bounds.top + cellHeight * (mPoints - 1) + cellHeight / 2;
        }
    }

    @Override
    public void draw(Canvas canvas) {
        if (isRunning()) {
            // animation in progress
            final int save = canvas.save();

            long timeDiff = SystemClock.uptimeMillis() - mStartTime;

            float progress = ((float) timeDiff) / ((float) mDuration); // 0..1
            int level = ((int) (progress * posX.length)) % posX.length; // current value 0..posX.length

            for (int i = 0; i < posX.length; i++) {
                if ((i >= level && i < level + mAnimatedPoints) || level + mAnimatedPoints > posX.length && i < (level + mAnimatedPoints) % posX.length) {
                    float num = (i - level + posX.length) % posX.length; // 0..5
                    float size = mSize * (1 + (num * (1f / mAnimatedPoints)));
                    float sizeNext = mSize * (1 + ((num + 1) * (1f / mAnimatedPoints)));

                    float levelProgress = progress * posX.length - (int) (progress * posX.length);
                    float currentSize;
                    if (num == (mAnimatedPoints - 1)) {
                        // grow to next size
                        currentSize = mSize + (size - mSize) * levelProgress;
                    } else {
                        // shrink
                        currentSize = size + (sizeNext - size) * (1 - levelProgress);
                    }

                    canvas.drawCircle(posX[i], posY[i], currentSize, mPaint);
                } else {
                    canvas.drawCircle(posX[i], posY[i], mSize, mPaint);
                }
            }

            canvas.restoreToCount(save);
        } else {
            // draw normal
            for (int i = 0; i < posX.length; i++) {
                canvas.drawCircle(posX[i], posY[i], mSize, mPaint);
            }
        }
    }

    @Override
    public void setBounds(int left, int top, int right, int bottom) {
        super.setBounds(left, top, right, bottom);
        init();
    }

    @Override
    public void setAlpha(int alpha) {

    }

    @Override
    public void setColorFilter(ColorFilter colorFilter) {

    }

    @Override
    public int getOpacity() {
        return 0;
    }

    @Override
    public void start() {
        if (mRunning) stop();
        mRunning = true;
        mStartTime = SystemClock.uptimeMillis();
        invalidateSelf();
        scheduleSelf(this, SystemClock.uptimeMillis() + FRAME_DELAY);
    }

    @Override
    public void stop() {
        unscheduleSelf(this);
        mRunning = false;
    }

    @Override
    public boolean isRunning() {
        return mRunning;
    }

    @Override
    public void run() {
        invalidateSelf();
        long uptimeMillis = SystemClock.uptimeMillis();
        if (uptimeMillis + FRAME_DELAY < mStartTime + mDuration) {
            scheduleSelf(this, uptimeMillis + FRAME_DELAY);
        } else {
            mRunning = false;
            start();
        }
    }

    public void setAnimatedPoints(int animatedPoints) {
        mAnimatedPoints = animatedPoints;
    }
}

用于
    ProgressBar progressBar = (ProgressBar) findViewById(R.id.progress);
    progressBar.setIndeterminateDrawable(new RectProgressDrawable());
    progressBar.setIndeterminate(true);

或者,您可以在正在运行的项目here中查看完整的源代码。

07-24 09:36
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