如何设置imageView的高和宽

我想在activity中改变图片视图的宽高属性，但是我用了下面的方法后没有实现：

View card_view = getLayoutInflater().inflate(R.layout.card_details1,null);
coupon_img = (ImageView) card_view.findViewById(R.id.coupon_image);
// I tried this ////////
coupon_img.getLayoutParams().height = 20;
coupon_img.getLayoutParams().width = 20;
// I also tried this ////
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(100, 100);
    coupon_img.setLayoutParams(layoutParams);
// also this one ////
coupon_img.setMaxHeight(10);

不知道为什么？应该怎么改才对呢？谢谢。

在这段代码中，创建了一个新的实例并且设置了尺寸：

// SET THE IMAGEVIEW DIMENSIONS
int dimens = 120;
float density = activity.getResources().getDisplayMetrics().density;
int finalDimens = (int)(dimens * density);

LinearLayout.LayoutParams imgvwDimens = 
        new LinearLayout.LayoutParams(finalDimens, finalDimens);
imgAlbumPhoto.setLayoutParams(imgvwDimens);

// SET SCALETYPE
imgAlbumPhoto.setScaleType(ScaleType.CENTER_CROP);

// SET THE MARGIN
int dimensMargin = 5;
float densityMargin = activity.getResources().getDisplayMetrics().density;
int finalDimensMargin = (int)(dimensMargin * densityMargin);

LinearLayout.LayoutParams imgvwMargin = 
        new LinearLayout.LayoutParams(finalDimens, finalDimens);
imgvwMargin.setMargins
(finalDimensMargin, finalDimensMargin, finalDimensMargin, finalDim

ensMargin);

改变已存在的ImageView尺寸，使用这个：

coupon_img.setLayoutParams(new LayoutParams(100, 100));

我看到个帖子说imageview不能动态修改宽高,可以生成你需要的imageview后将原来的移除,再重新添加