Android ImageView未缩放到屏幕宽度

Question

我正在使用以下功能将任何图像缩放到屏幕宽度：

DisplayMetrics metrics = new DisplayMetrics();
((Activity)context)
.getWindowManager()
.getDefaultDisplay()
.getMetrics(metrics);

int width = bitmap.getWidth();
int height = bitmap.getHeight();

// Calculate the ratio between height and width of Original Image
float ratio = (float) height / (float) width;

int newWidth = metrics.widthPixels; // This will be equal to screen width
float newHeight = newWidth * ratio; // This will be according to the ratio calulated

// calculate the scale
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = newHeight / height;

// create a matrix for the manipulation
Matrix matrix = new Matrix();

// resize the bit map
matrix.postScale(scaleWidth, scaleHeight);

// recreate the new Bitmap
Bitmap resizedBitmap
    = Bitmap.createBitmap(
                bitmap, 0, 0,
                width, height,
                matrix, true
);

// make a Drawable from Bitmap to allow to set the BitMap
// to the ImageView, ImageButton or what ever
return new BitmapDrawable(resizedBitmap);

进行一些检查后，值为 metrics.widthPixels = 540 ，新位图的宽度也为540.这意味着Bitmap或Imageview应使用全屏宽度。相反，生成的图像视图缺少全屏宽度。我包括一个截图：

如图所示，屏幕的剩余空白部分以黑色显示。

创建ImageView的代码是：

ImageView imageBanner = new ImageView(context);
imageBanner.setLayoutParams(new
    LinearLayout.LayoutParams(
        Globals.wrapContent,
        Globals.wrapContent));
imageBanner.setBackgroundResource(R.drawable.imv_banner);
new SyncImage(context, imageBanner, urlImage).execute();

Globals.wrapContent是显式常量，它包含标准布局参数的相同值，因此不要将它们视为不同。 SyncImage用于在ImageView中下载和显示图像的异步类。

请提供解决方案，将图像缩放到全屏宽度，图像应保持原始尺寸比。

谢谢 Ram Ram

Answer 1

将imageView的宽度设置为MatchParent而不是WrapContent，并计算高度以保持图像的宽高比。请尝试以下代码来调整图像大小：

    Display display = getActivity().getWindowManager().getDefaultDisplay();
    Point size = new Point();
    display.getSize(size);
    int newWidth = size.x;

    //Get actual width and height of image
    int width = bitmap.getWidth();
    int height = bitmap.getHeight();

    // Calculate the ratio between height and width of Original Image
    float ratio = (float) height / (float) width;
    float scale = getApplicationContext().getResources().getDisplayMetrics().density;
    int newHeight = (int) (width * ratio)/scale;

    return Bitmap.createScaledBitmap(bitmap, newWidth, newHeight, true);