如何在不降低质量的情况下在任何屏幕上显示png / jpg图像?

时间:2016-07-06 05:22:45

标签: android image imageview android-imageview

我知道它有点棘手,仍然在想是否可能,但我想在我使用矢量Drawable 的时候调整我的图像而不降低任何Android设备上的图像质量非常方便,但有时大小的矢量不是内存效率所以我不想使用它们。虽然我想知道是否有任何方法可以调整简单的 PNG JPEG 文件与Android中的分辨率和屏幕大小无关?

如果有人能给我路,那将是非常有帮助!!

1 个答案:

答案 0 :(得分:1)

使用调整图像视图(自定义图像视图)

  public class ResizableImageView extends ImageView {
    public ResizableImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public ResizableImageView(Context context) {
        super(context);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        Drawable d = getDrawable();
        // get drawable from imageview
        if (d == null) {
            super.setMeasuredDimension(widthMeasureSpec, heightMeasureSpec);
            return;
        }

        int imageHeight = d.getIntrinsicHeight();
        int imageWidth = d.getIntrinsicWidth();
        // get height and width of the drawable
        int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        int heightSize = MeasureSpec.getSize(heightMeasureSpec);
        // get width and height extracts the size from the supplied measure specification.
        float imageRatio = 0.0F;
        if (imageHeight > 0) {
            imageRatio = imageWidth / imageHeight;
        }
        float sizeRatio = 0.0F;
        if (heightSize > 0) {
            sizeRatio = widthSize / heightSize;
        }

        int width;
        int height;
        if (imageRatio >= sizeRatio) {
            // set width to maximum allowed
            width = widthSize;
            // scale height
            height = width * imageHeight / imageWidth;
        } else {
            // set height to maximum allowed
            height = heightSize;
            // scale width
            width = height * imageWidth / imageHeight;
        }

        setMeasuredDimension(width, height);
        // This method must be called to store the measured width and measured height. Failing to do so will trigger an exception at measurement time
    }
}
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