修改进度条的资源图像

Question

我想为Android创建一个进度条.我的方形进度条有四个图像.

我正在使用android定义的进度条:

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

但是,如果我想制作一个正方形而不是圆形,我该怎么办呢？如何将4张图像传递到进度条？

例:

Answer 1

通常你有2个选择:

1.如前所述,使用animation-list和交换图片.

这个可能是更简单的解决方案,因为它们可以通过AnimationDrawable相对容易地进行动画处理.唯一的缺点是您需要至少16张图像(在所有分辨率下)用于您的给定结果.

2.使用自定义drawable.

这是更复杂的方法.您将不得不自己进行绘图和动画制作,对于大多数没有良好文档的人来说,这是一项艰巨的任务.

因此,您必须extends Drawable implements Runnable, Animatable提供一些好的实现.

以下是基本的实现,计算一次位置,然后绘制它们.动画(各个圆圈的大小)可以而且应该进一步调整;)

结果有3种变体:

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;
    }
}

使用

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

或者,您可以在此处查看工作项目中的完整源代码

Answer 2

我正在用一堆图像来做这件事animation-list:

<?xml version="1.0" encoding="utf-8"?>
<ImageView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/loadingAnimationImageView"
    android:layout_width="36dp"
    android:layout_height="36dp"
    android:background="@drawable/loading_progress_indicator_animation" />

而且res\drawable\loading_progres_indicator_animation.xml:

<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/selected"
    android:oneshot="false">
    <item
        android:drawable="@drawable/loading_progress_indicator_0"
        android:duration="40" />
    <item
        android:drawable="@drawable/loading_progress_indicator_1"
        android:duration="40" />
    <item
        android:drawable="@drawable/loading_progress_indicator_2"
        android:duration="40" />
    .....
    <item
        android:drawable="@drawable/loading_progress_indicator_11"
        android:duration="40" />
    <item
        android:drawable="@drawable/loading_progress_indicator_12"
        android:duration="40" />
</animation-list>

每个loading_progress_indicator_XX图像都是进度状态指示器.

带指示符的自定义视图:

public final class LoadingAnimationView extends FrameLayout {

    ImageView loadingAnimationImageView;
    AnimationDrawable loadingProgressAnimation;
    Handler handler = new Handler(Looper.getMainLooper());

    public LoadingAnimationView(Context context) {
        super(context);
        initialize();
    }

    private void initialize() {
        LayoutInflater.from(getContext()).inflate(R.layout.view_loading_videoview, this);
        loadingAnimationImageView = (ImageView)getView().findViewById(R.id.loadingAnimationImageView);
        loadingProgressAnimation = (AnimationDrawable) loadingAnimationImageView.getBackground();
        adaptToVisibility(getVisibility());
    }

    @Override
    public void setVisibility(int visibility) {
        super.setVisibility(visibility);
        adaptToVisibility(visibility);
    }

    void adaptToVisibility(final int visibility) {
        if (visibility == VISIBLE) {
            loadingProgressAnimation.start();
            //This is to avoid "blinking" of progress indicator (if page is loading from cache)
            handler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    loadingAnimationImageView.setVisibility(visibility);
                }
            }, 200);
        } else {
            loadingProgressAnimation.stop();
            loadingAnimationImageView.setVisibility(visibility);
        }
    }
}

因此,在我的情况下,它看起来像:

因此,您需要的只是指标和自定义视图的状态,如上所示.

要获取指标的状态,您可以转换gif为png我建议使用EzGif服务的列表:

另一种选择 - 您可以重复使用加载指示器的几十个自定义实现中的一个(如果它有一些足够接近您的指示符)或这个(尽管,大多数开源指标是循环的).

我希望它有所帮助.