使用Picasso将图像调整为全宽和可变高度

Question

我有一个带有适配器的listView，其中包含可变大小（宽度和高度）的ImageView。我需要将Picasso的图片大小调整为布局的最大宽度和图片宽高比给出的可变高度。

我检查了这个问题： Resize image to full width and fixed height with Picasso

fit()有效，但我没有找到任何保持图片宽高比的内容。

如果我在适配器的布局中修改了高度，则此代码部分有效：

Picasso.with(this.context).load(message_pic_url)
.placeholder(R.drawable.profile_wall_picture)
.fit().centerInside()
.into(holder.message_picture);

但是它会在listView的图片之间生成空格，因为图片可能没有那么高。

提前致谢。

Answer 1

截至毕加索2.4.0，this operation is now directly supported。只需添加一个.resize()请求，其中一个维度为0。例如，要使宽度可变，您的调用将变为：

Picasso.with(this.context)
       .load(message_pic_url)
       .placeholder(R.drawable.profile_wall_picture)
       .resize(0, holder.message_picture.getHeight()),
       .into(holder.message_picture);

请注意，此次调用使用.getHeight()，因此假设message_picture已经过测量。如果不是这种情况，例如当您在ListAdapter中夸大了新视图时，可以通过向视图添加OnGlobalLayoutListener来延迟此调用，直到测量完毕：

holder.message_picture.getViewTreeObserver()
      .addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            // Wait until layout to call Picasso
            @Override
            public void onGlobalLayout() {
                // Ensure we call this only once
                imageView.getViewTreeObserver()
                         .removeOnGlobalLayoutListener(this);


                Picasso.with(this.context)
                       .load(message_pic_url)
                       .placeholder(R.drawable.profile_wall_picture)
                       .resize(0, holder.message_picture.getHeight())
                       .into(holder.message_picture);
            }
        });

Answer 2

我遇到了同样的问题，我花了一些时间来追踪解决方案，但我终于找到了适合我的东西。

首先，我将毕加索的电话改为

Picasso.with(this.context).load(message_pic_url)
.placeholder(R.drawable.profile_wall_picture)
.into(holder.message_picture);

删除fit和centerInside。接下来，您需要将以下行添加到XML中的ImageView

android:scaleType="fitStart"
android:adjustViewBounds="true"

希望它也适合你。

Answer 3

最后我解决了Picasso的改造，这里是片段：

    Transformation transformation = new Transformation() {

        @Override
        public Bitmap transform(Bitmap source) {
            int targetWidth = holder.message_picture.getWidth();

            double aspectRatio = (double) source.getHeight() / (double) source.getWidth();
            int targetHeight = (int) (targetWidth * aspectRatio);
            Bitmap result = Bitmap.createScaledBitmap(source, targetWidth, targetHeight, false);
            if (result != source) {
                // Same bitmap is returned if sizes are the same
                source.recycle();
            }
            return result;
        }

        @Override
        public String key() {
            return "transformation" + " desiredWidth";
        }
    };

    mMessage_pic_url = message_pic_url;

    Picasso.with(this.context)
        .load(message_pic_url)
        .error(android.R.drawable.stat_notify_error)
        .transform(transformation)
        .into(holder.message_picture, new Callback() {
            @Override
            public void onSuccess() {
                holder.progressBar_picture.setVisibility(View.GONE);
            }

            @Override
            public void onError() {
                Log.e(LOGTAG, "error");
                holder.progressBar_picture.setVisibility(View.GONE);
            }
    });

此行用于自定义您想要的宽度：

int targetWidth = holder.message_picture.getWidth();

此外，此剪辑还包括用于加载隐藏的回调和错误可绘制的内置毕加索。

如果您需要更多信息来调试任何错误，您必须实现自定义侦听器（Picasso构建器），因为onError Callback信息为“null”。您只知道UI行为存在错误。

我希望这可以帮助别人节省很多时间。

Answer 4

可以 Accepted 答案对所有人都有用但如果你绑定了多个ViewHolder多个Views，那么你可以通过为<创建类来减少代码strong>转换并从ViewHolder传递 ImageView 。

/**
 * Created by Pratik Butani
 */
public class ImageTransformation {

    public static Transformation getTransformation(final ImageView imageView) {
        return new Transformation() {

            @Override
            public Bitmap transform(Bitmap source) {
                int targetWidth = imageView.getWidth();

                double aspectRatio = (double) source.getHeight() / (double) source.getWidth();
                int targetHeight = (int) (targetWidth * aspectRatio);
                Bitmap result = Bitmap.createScaledBitmap(source, targetWidth, targetHeight, false);
                if (result != source) {
                    // Same bitmap is returned if sizes are the same
                    source.recycle();
                }
                return result;
            }

            @Override
            public String key() {
                return "transformation" + " desiredWidth";
            }
        };
    }
}

来自ViewHolder：

Picasso.with(context).load(baseUrlForImage)
                     .transform(ImageTransformation.getTransformation(holder.ImageView1))
                     .error(R.drawable.ic_place_holder_circle)
                     .placeholder(R.drawable.ic_place_holder_circle)
                     .into(holder.mMainPhotoImageView1);

希望它会帮助你。

Answer 5

    Picasso.with(this).load(url).resize(1800, 1800).centerInside().into(secondImageView)

    <ImageView
        android:id="@+id/SecondImage"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentLeft="true"
        android:adjustViewBounds="true"
        android:layout_margin="10dp"
        android:visibility="gone"/>

这将帮助您处理所有设备的图像高度变化

Answer 6

我已经编写了简单的帮助程序，在布局过程完成时，需要注意添加布局完整的侦听器并调用（imageView）。

public class PicassoDelegate {

private RequestCreator mRequestCreator;

public PicassoDelegate(ImageView target, RequestCreator requestCreator) {
    if (target.getWidth() > 0 && target.getHeight() > 0) {
        complete(target, requestCreator);
    } else {
        mRequestCreator = requestCreator;
        target.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
            @Override
            public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
                v.removeOnLayoutChangeListener(this);
                complete((ImageView) v, mRequestCreator);
            }
        });

    }

}

private void complete(ImageView target, RequestCreator requestCreator) {
    if (target.getWidth() > 0 && target.getHeight() > 0) {
        requestCreator.resize(target.getWidth(), target.getHeight());
    }

    requestCreator.into(target);
}

}

所以你可以很容易地使用它，比如片段的onViewCreated（）

new PicassoDelegate(customerPhoto, Picasso.with(getActivity()).load(user.getPhotoUrl()).centerCrop());

Answer 7

imageView.post(new Runnable() {
      @Override public void run() {
        Picasso.with(context)
            .resize(0, imageView.getHeight())
            .onlyScaleDown()
            .into(imageView, new ImageCallback(callback, null));
      }
    });

Answer 8

扩展ImageView，然后覆盖onMeasure方法，如下所示。

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

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

Answer 9

实际上我在CustomImageView中加载具有可缩放功能的图像时进入

错误是

java.lang.RuntimeException: Transformation transformation desiredWidth crashed with exception.

我通过编辑从接受的答案中给出的代码解决了这个问题我得到了显示器的最大宽度，好像我的imageview宽度已经是match_parent。

if（！imgUrl.equals（＆＃34;＆＃34;））{

        DisplayMetrics displayMetrics = new DisplayMetrics();
        ((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        int height = displayMetrics.heightPixels;
        int width = displayMetrics.widthPixels;

        Picasso.with(context).load(imgUrl)
                .transform(getTransformation(width, imageView))
                .into(imageView, new Callback() {
                    @Override
                    public void onSuccess() {
                        if (progressBar != null) {
                            progressBar.setVisibility(View.GONE);
                        }
                    }

                    @Override
                    public void onError() {
                        if (progressBar != null) {
                            progressBar.setVisibility(View.GONE);
                        }
                    }
                });
    }

    public static Transformation getTransformation(final int width, final ImageView imageView) {
        return new Transformation() {
            @Override
            public Bitmap transform(Bitmap source) {
                int targetWidth = width;
                double aspectRatio = (double) source.getHeight() / (double) source.getWidth();
                int targetHeight = (int) (targetWidth * aspectRatio);
                Bitmap result = Bitmap.createScaledBitmap(source, targetWidth, targetHeight, false);
                if (result != source) {
                    // Same bitmap is returned if sizes are the same
                    source.recycle();
                }
                return result;
            }

            @Override
            public String key() {
                return "transformation" + " desiredWidth";
            }
        };
    }

Answer 10

Picasso.get()
.load(message_pic_url)
.fit()
.centerCrop()
.placeholder(R.drawable.profile_wall_picture)
.into(holder.message_picture);

尝试此代码，为我工作。

Answer 11

@Override
    protected void onResume() {
        super.onResume();

        imageView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                loadImageIfReady();
            }
        });

    }

    private void loadImageIfReady() {
        if (imageView.getMeasuredWidth() <= 0 || mPayload == null)
            this.finish();    // if not ready GTFO

        Picasso.with(this)
                    .load(mPayload)
                    .resize(imageView.getMeasuredWidth(), imageView.getMeasuredWidth())
                    .centerInside()
                    .into(imageView);


    }