试图获得的图像的显示尺寸在ImageView的 [英] Trying to get the display size of an image in an ImageView

问题描述

我想要得到的图像视图中显示图像的实际大小。其实我的形象是大于屏幕和ImageView的是在调整图像以diplay它。我在寻找这个新的大小。

I'm trying to get the real size of an image displayed in an image view. Actually my image is larger than the screen and the imageview is resizing the image to diplay it. I'm looking for this new size.

我试图覆盖在自定义视图中的ImageView的OnDraw的方法，但我没有得到正确的高度和宽度...

I've tried to override the onDraw method of the ImageView in a custom view but I'm not getting the correct height and width...

public class LandImageView extends ImageView
{
    public LandImageView( Context context )
    {
        super( context );
    }

    public LandImageView(Context context, AttributeSet attrs)
    {
        super(context, attrs);
    }

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

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

        int test = this.getWidth();
        int test2 = this.getHeight();
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh)
    {
        super.onSizeChanged(w, h, oldw, oldh);
    }
}

你有没有什么线索？

Do you have any clues ?

推荐答案

没有问题的答案在这里居然回答这个问题：

None of the answers here actually answer the question:

从位图由的ImageView 显示的任何尺寸，找到实际尺寸所显示的图像的作为反对的尺寸所提供的位图。的

From a Bitmap of any size displayed by an ImageView, find the actual dimensions of the displayed image as opposed to the dimensions of the supplied Bitmap.

即：

• 使用 ImageView.getDrawable（）。getInstrinsicWidth（）和 getIntrinsicHeight（）都将返回原来的尺寸。
• 获取绘制对象到 ImageView.getDrawable（），并将其转换成一 BitmapDrawable ，然后用 BitmapDrawable.getBitmap（）的getWidth（）和的getHeight（）还返回原始图像和它的尺寸。

• Using ImageView.getDrawable().getInstrinsicWidth() and getIntrinsicHeight() will both return the original dimensions.
• Getting the Drawable through ImageView.getDrawable() and casting it to a BitmapDrawable, then using BitmapDrawable.getBitmap().getWidth() and getHeight() also returns the original image and its dimensions.

获得的唯一方法在实际显示的图像尺寸是通过提取和利用，改造矩阵用于显示图像，因为它被示出。这必须在测量阶段之后完成这里的例子显示了它在 onMeasure（）的覆盖呼吁自的ImageView ：

The only way to get the actual dimensions of the displayed image is by extracting and using the transformation Matrix used to display the image as it is shown. This must be done after the measuring stage and the example here shows it called in an Override of onMeasure() for a custom ImageView:

public class SizeAwareImageView extends ImageView {

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

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        // Get image matrix values and place them in an array
        float[] f = new float[9];
        getImageMatrix().getValues(f);

        // Extract the scale values using the constants (if aspect ratio maintained, scaleX == scaleY)
        final float scaleX = f[Matrix.MSCALE_X];
        final float scaleY = f[Matrix.MSCALE_Y];

        // Get the drawable (could also get the bitmap behind the drawable and getWidth/getHeight)
        final Drawable d = getDrawable();
        final int origW = d.getIntrinsicWidth();
        final int origH = d.getIntrinsicHeight();

        // Calculate the actual dimensions
        final int actW = Math.round(origW * scaleX);
        final int actH = Math.round(origH * scaleY);

        Log.e("DBG", "["+origW+","+origH+"] -> ["+actW+","+actH+"] & scales: x="+scaleX+" y="+scaleY);
    }

}  

注意：：要获取图像变换矩阵从code一般（如在活动），功能 ImageView.getImageMatrix（） - 如 myImageView.getImageMatrix（）

Note: To get the image transformation Matrix from code in general (like in an Activity), the function is ImageView.getImageMatrix() - e.g. myImageView.getImageMatrix()

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