我有一个GridView。GridView的数据是来自服务器的请求。

下面是GridView中的项目布局:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/analysis_micon_bg"
    android:gravity="center_horizontal"
    android:orientation="vertical"
    android:paddingBottom="@dimen/half_activity_vertical_margin"
    android:paddingLeft="@dimen/half_activity_horizontal_margin"
    android:paddingRight="@dimen/half_activity_horizontal_margin"
    android:paddingTop="@dimen/half_activity_vertical_margin" >

    <ImageView
        android:id="@+id/ranking_prod_pic"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:adjustViewBounds="true"
        android:contentDescription="@string/app_name"
        android:scaleType="centerCrop" />

    <TextView
        android:id="@+id/ranking_rank_num"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/ranking_prod_num"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/ranking_prod_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

我从服务器请求数据,获取图像url和加载图像到位图

public static Bitmap loadBitmapFromInputStream(InputStream is) {
    return BitmapFactory.decodeStream(is);
}

public static Bitmap loadBitmapFromHttpUrl(String url) {
    try {
        return loadBitmapFromInputStream((InputStream) (new URL(url).getContent()));
    } catch (Exception e) {
        Log.e(TAG, e.getMessage());
        return null;
    }
}

适配器中有getView(int position, View convertView, ViewGroup parent)方法的代码

Bitmap bitmap = BitmapUtil.loadBitmapFromHttpUrl(product.getHttpUrl());
prodImg.setImageBitmap(bitmap);

图像大小为210*210。我在Nexus 4上运行我的应用程序。图像填充ImageView的宽度,但ImageView的高度没有缩放。ImageView不显示整个图像。

我怎么解决这个问题?


当前回答

要创建宽度等于屏幕宽度的图像,并且根据纵横比按比例设置高度,请执行以下操作。

Glide.with(context).load(url).asBitmap().into(new SimpleTarget<Bitmap>() {
                    @Override
                    public void onResourceReady(Bitmap resource, GlideAnimation<? super Bitmap> glideAnimation) {

                        // creating the image that maintain aspect ratio with width of image is set to screenwidth.
                        int width = imageView.getMeasuredWidth();
                        int diw = resource.getWidth();
                        if (diw > 0) {
                            int height = 0;
                            height = width * resource.getHeight() / diw;
                            resource = Bitmap.createScaledBitmap(resource, width, height, false);
                        }
                                              imageView.setImageBitmap(resource);
                    }
                });

希望这能有所帮助。

其他回答

我做了类似上面的事情,然后把我的头撞在墙上几个小时,因为它在RelativeLayout中不起作用。我最终得到了以下代码:

package com.example;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public class ScaledImageView extends ImageView {
    public ScaledImageView(final Context context, final AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec) {
        final Drawable d = getDrawable();

        if (d != null) {
            int width;
            int height;
            if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.EXACTLY) {
                height = MeasureSpec.getSize(heightMeasureSpec);
                width = (int) Math.ceil(height * (float) d.getIntrinsicWidth() / d.getIntrinsicHeight());
            } else {
                width = MeasureSpec.getSize(widthMeasureSpec);
                height = (int) Math.ceil(width * (float) d.getIntrinsicHeight() / d.getIntrinsicWidth());
            }
            setMeasuredDimension(width, height);
        } else {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }
}

然后为了防止RelativeLayout忽略测量的维度,我这样做:

    <FrameLayout
        android:id="@+id/image_frame"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/something">

        <com.example.ScaledImageView
            android:id="@+id/image"
            android:layout_width="wrap_content"
            android:layout_height="150dp"/>
    </FrameLayout>

我喜欢arnefm的回答,但他犯了一个小错误(见评论),我会尽力纠正:

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

/**
 * ImageView that keeps aspect ratio when scaled
 */
public class ScaleImageView extends ImageView {

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

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

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

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    try {
      Drawable drawable = getDrawable();
      if (drawable == null) {
        setMeasuredDimension(0, 0);
      } else {
        int measuredWidth = MeasureSpec.getSize(widthMeasureSpec);
        int measuredHeight = MeasureSpec.getSize(heightMeasureSpec);
        if (measuredHeight == 0 && measuredWidth == 0) { //Height and width set to wrap_content
          setMeasuredDimension(measuredWidth, measuredHeight);
        } else if (measuredHeight == 0) { //Height set to wrap_content
          int width = measuredWidth;
          int height = width *  drawable.getIntrinsicHeight() / drawable.getIntrinsicWidth();
          setMeasuredDimension(width, height);
        } else if (measuredWidth == 0){ //Width set to wrap_content
          int height = measuredHeight;
          int width = height * drawable.getIntrinsicWidth() / drawable.getIntrinsicHeight();
          setMeasuredDimension(width, height);
        } else { //Width and height are explicitly set (either to match_parent or to exact value)
          setMeasuredDimension(measuredWidth, measuredHeight);
        }
      }
    } catch (Exception e) {
      super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
  }

}

因此,你的ImageView将适当缩放,将没有尺寸问题,如果(例如)放在ScrollView

使用android: scaleType = " centerCrop”。

FOR IMAGE VIEW(设置这些参数)

android:layout_width     = "match_parent"
android:layout_height    = "wrap_content"
android:scaleType        = "fitCenter"
android:adjustViewBounds = "true"

不管图像的大小是多少,它的宽度会匹配父元素高度会根据比例匹配。我已经测试过了,我百分百确定。

我们想要这个——>

不是这个——>

// Results will be: 
Image width -> stretched as match parent
Image height -> according to image width (maximum to aspect ratio)

// like the first one

使用ImageView中的这些属性来保持纵横比:

android:adjustViewBounds="true"
android:scaleType="fitXY"