我试图计算这个形象，这将从网络使用此行 imgLoader.DisplayImage（URL，R.drawable.thumbnail_background，图像）下载尺寸; 。 的问题是，orgHeight变为零，并且无法除以零。但是，为什么是这样的 orgHeight 0？

  //添加ImageView的，并计算其尺寸
        //假设你的布局是一个的LinearLayout作为它的根
        的LinearLayout布局=（的LinearLayout）findViewById（R.id.layout）;

        ImageView的形象=（ImageView的）findViewById（R.id.photo）;

        ImageLoader的imgLoader =新ImageLoader的（getApplicationContext（））;
        imgLoader.DisplayImage（URL，R.drawable.thumbnail_background，图像）;

        INT newHeight = getWindowManager（）getDefaultDisplay（）的getHeight（）/ 2。。;
        INT orgWidth = image.getWidth（）;
        INT orgHeight = image.getHeight（）;

        //仔细检查我的数学，这应该是对的，尽管
        INT newWidth =（INT）Math.floor（（orgWidth * newHeight）/ orgHeight）;

        //使用RelativeLayout.LayoutParams如果你的父母是一个RelativeLayout的
        LinearLayout.LayoutParams PARAMS =新LinearLayout.LayoutParams（
            newWidth，newHeight）;
        image.setLayoutParams（PARAMS）;
        image.setScaleType（ImageView.ScaleType.CENTER_CROP）;
        layout.updateViewLayout（图像，则params）;
 

我的ImageView的XML是这样的：

 ＆LT; ImageView的
            机器人：ID =@ + ID /摄
            机器人：layout_width =WRAP_CONTENT
            机器人：layout_height =WRAP_CONTENT
            机器人：layout_weight =1
        /＆GT;
 

解决方案

的意见尚未铺设在的onCreate（）方法，因此它们的尺寸都为0帖子一个的Runnable 从的onCreate（），以获得正确的值：

  image.post（新的Runnable（）{

 @覆盖
 公共无效的run（）{
    INT newHeight = getWindowManager（）getDefaultDisplay（）的getHeight（）/ 2。。;
    INT orgWidth = image.getWidth（）;
    INT orgHeight = image.getHeight（）;

    //仔细检查我的数学，这应该是对的，尽管
    INT newWidth =（INT）Math.floor（（orgWidth * newHeight）/ orgHeight）;

    //使用RelativeLayout.LayoutParams如果你的父母是一个RelativeLayout的
    LinearLayout.LayoutParams PARAMS =新LinearLayout.LayoutParams（
        newWidth，newHeight）;
    image.setLayoutParams（PARAMS）;
    image.setScaleType（ImageView.ScaleType.CENTER_CROP）;
    layout.updateViewLayout（图像，则params）;
 }

}）;
 

I'm trying to calculate the dimension for this image, which will be downloaded from the web using this lineimgLoader.DisplayImage(url, R.drawable.thumbnail_background, image);. The problem is that orgHeight becomes zero and you can't divide by zero. But why is this orgHeight 0?

// Add the imageview and calculate its dimensions
        //assuming your layout is in a LinearLayout as its root
        LinearLayout layout = (LinearLayout)findViewById(R.id.layout);

        ImageView image = (ImageView)findViewById(R.id.photo);

        ImageLoader imgLoader = new ImageLoader(getApplicationContext());
        imgLoader.DisplayImage(url, R.drawable.thumbnail_background, image);

        int newHeight = getWindowManager().getDefaultDisplay().getHeight() / 2;
        int orgWidth = image.getWidth();
        int orgHeight = image.getHeight();

        //double check my math, this should be right, though
        int newWidth = (int) Math.floor((orgWidth * newHeight) / orgHeight);

        //Use RelativeLayout.LayoutParams if your parent is a RelativeLayout
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
            newWidth, newHeight);
        image.setLayoutParams(params);
        image.setScaleType(ImageView.ScaleType.CENTER_CROP);
        layout.updateViewLayout(image, params);     

My imageView xml is like this:

<ImageView
            android:id="@+id/photo"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
        />  

The views aren't yet laid in the onCreate() method so their dimensions are 0. Post a Runnable from onCreate() to get the proper values:

image.post(new Runnable() {

 @Override
 public void run() {
    int newHeight = getWindowManager().getDefaultDisplay().getHeight() / 2;
    int orgWidth = image.getWidth();
    int orgHeight = image.getHeight();

    //double check my math, this should be right, though
    int newWidth = (int) Math.floor((orgWidth * newHeight) / orgHeight);

    //Use RelativeLayout.LayoutParams if your parent is a RelativeLayout
    LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
        newWidth, newHeight);
    image.setLayoutParams(params);
    image.setScaleType(ImageView.ScaleType.CENTER_CROP);
    layout.updateViewLayout(image, params);      
 } 

});