android - 实现9个旧Android薄片的问题

我是android的菜鸟，我正在尝试在我的应用程序中实现9个旧的Android薄片演示。但是，当我将图像资源从演示所使用的图像更改为我选择的应用程序之一时崩溃，并说IllegalArgumentException：width和height必须大于0。我的logcat说我createscaledbitmap和createFlake所在的行引起了问题。我不知道为什么会这样，演示图像的宽度为75px x 90px，而我的图像的宽度为166px x 72px。任何帮助是极大的赞赏。

FLAKE VIEW CLASS（我在其中创建Flake的地方）

void addFlakes(int quantity) {
    for (int i = 0; i < quantity; ++i) {
        flakes.add(Flake.createFlake(getWidth(), droid)); //This line causes exception
    }
    setNumFlakes(numFlakes + quantity);
}

/**
 * Subtract the specified number of droidflakes. We just take them off the end of the
 * list, leaving the others unchanged.
 */
void subtractFlakes(int quantity) {
    for (int i = 0; i < quantity; ++i) {
        int index = numFlakes - i - 1;
        flakes.remove(index);
    }
    setNumFlakes(numFlakes - quantity);
}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    // Reset list of droidflakes, then restart it with 8 flakes
    flakes.clear();
    numFlakes = 0;
    addFlakes(8); //This line causes exception
    // Cancel animator in case it was already running
    animator.cancel();
    // Set up fps tracking and start the animation
    startTime = System.currentTimeMillis();
    prevTime = startTime;
    frames = 0;
    animator.start();
}

FLAKE CLASS（在其中创建缩放位图的地方）

static Flake createFlake(float xRange, Bitmap originalBitmap) {
    Flake flake = new Flake();
    // Size each flake with a width between 5 and 55 and a proportional height
    flake.width = (int)(5 + (float)Math.random() * 50);
    float hwRatio = originalBitmap.getHeight() / originalBitmap.getWidth();
    flake.height = (int)(flake.width * hwRatio);

    // Position the flake horizontally between the left and right of the range
    flake.x = (float)Math.random() * (xRange - flake.width);
    // Position the flake vertically slightly off the top of the display
    flake.y = 0 - (flake.height + (float)Math.random() * flake.height);

    // Each flake travels at 50-200 pixels per second
    flake.speed = 50 + (float) Math.random() * 150;

    // Flakes start at -90 to 90 degrees rotation, and rotate between -45 and 45
    // degrees per second
    flake.rotation = (float) Math.random() * 180 - 90;
    flake.rotationSpeed = (float) Math.random() * 90 - 45;

    // Get the cached bitmap for this size if it exists, otherwise create and cache one
    flake.bitmap = bitmapMap.get(flake.width);
    if (flake.bitmap == null) {
        flake.bitmap = Bitmap.createScaledBitmap(originalBitmap, //This line causes exception
                (int)flake.width, (int)flake.height, true);
        bitmapMap.put(flake.width, flake.bitmap);
    }
    return flake;
}

最佳答案

由于图像的宽度大于高度，因此您基本上需要反转这三行代码。

flake.width = (int)(5 + (float)Math.random() * 50);
float hwRatio = originalBitmap.getHeight() / originalBitmap.getWidth();
flake.height = (int)(flake.width * hwRatio);

对此

flake.height = (int)(5 + (float)Math.random() * 50);
float hwRatio = originalBitmap.getWidth() / originalBitmap.getheight();
flake.width = (int)(flake.height * hwRatio);