这招对我很管用:

android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxWidth="39dip"
android:scaleType="centerCrop"
android:adjustViewBounds ="true"

Yes, by default Android will scale your image down to fit the ImageView, maintaining the aspect ratio. However, make sure you're setting the image to the ImageView using android:src="..." rather than android:background="...". src= makes it scale the image maintaining aspect ratio, but background= makes it scale and distort the image to make it fit exactly to the size of the ImageView. (You can use a background and a source at the same time though, which can be useful for things like displaying a frame around the main image, using just one ImageView.) You should also see android:adjustViewBounds to make the ImageView resize itself to fit the rescaled image. For example, if you have a rectangular image in what would normally be a square ImageView, adjustViewBounds=true will make it resize the ImageView to be rectangular as well. This then affects how other Views are laid out around the ImageView. Then as Samuh wrote, you can change the way it default scales images using the android:scaleType parameter. By the way, the easiest way to discover how this works would simply have been to experiment a bit yourself! Just remember to look at the layouts in the emulator itself (or an actual phone) as the preview in Eclipse is usually wrong.

给其他有这种问题的人。你有一个ImageView，你想要它的宽度为fill_parent，高度按比例缩放:

添加这两个属性到你的ImageView:

android:adjustViewBounds="true"
android:scaleType="centerCrop"

并设置ImageView的宽度为fill_parent，高度为wrap_content。

另外，如果你不想让你的图像被裁剪，试试这个:

 android:adjustViewBounds="true"
 android:layout_centerInParent="true"

imageView.setImageBitmap(Bitmap.createScaledBitmap(bitmap, 130, 110, false));

你可以计算屏幕宽度。你可以缩放位图。

 public static float getScreenWidth(Activity activity) {
        Display display = activity.getWindowManager().getDefaultDisplay();
        DisplayMetrics outMetrics = new DisplayMetrics();
        display.getMetrics(outMetrics);
        float pxWidth = outMetrics.widthPixels;
        return pxWidth;
    }

计算屏幕宽度和按屏幕宽度缩放的图像高度。

float screenWidth=getScreenWidth(act)
  float newHeight = screenWidth;
  if (bitmap.getWidth() != 0 && bitmap.getHeight() != 0) {
     newHeight = (screenWidth * bitmap.getHeight()) / bitmap.getWidth();
  }

之后就可以缩放位图了。

Bitmap scaledBitmap=Bitmap.createScaledBitmap(bitmap, (int) screenWidth, (int) newHeight, true);

您可以缩放图像，这也将减少图像的大小。 你可以下载并使用它的库。 https://github.com/niraj124124/Images-Files-scale-and-compress.git

如何使用 1)导入压缩器-v1.0。Jar到您的项目。 2)添加下面的示例代码进行测试。 ResizeLimiter resize = ImageResizer.build(); 调整大小。scale("inputImagePath"， "outputImagePath"，imageWidth, imageHeight); 根据您的要求，还有更多的方法