Question

我有这张图片：

这就是它出现在小型设备上的方式：

看起来有点软弱。我希望它不会调整大小，按原样显示，不显示不适合屏幕的图像部分。喜欢这个

如果您没有注意到，上面图片中的手机屏幕背景不会调整大小，它只需要从中心图像适合屏幕。它可以切割不适合屏幕的部件，并从中心获取所需的部件。

当我在平板电脑上使用它时，它完美无缺，因为平板电脑的屏幕尺寸很大：

我该怎么做？

目前，这是我的代码：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout   
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:id="@+id/activity_sign_in"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context="com.alibdeir.irecipify.SignInActivity"
  android:background="@drawable/food_wallpaper">

</android.support.constraint.ConstraintLayout>

Answer 1

我通过创建ScaleImageView java类来修复它：

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

/**
 * Created by Ab-Me on 25-Aug-16.
 * This is the imageView for the background image
 */
@SuppressWarnings("all")
public class ScaleImageView extends ImageView {
    private ImageChangeListener imageChangeListener;
    private boolean scaleToWidth = false; // this flag determines if should measure height manually dependent of width

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

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

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

    private void init() {
        this.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
    }

    @Override
    public void setImageBitmap(Bitmap bm) {
        super.setImageBitmap(bm);
        if (imageChangeListener != null)
            imageChangeListener.changed((bm == null));
    }

    @Override
    public void setImageDrawable(Drawable d) {
        super.setImageDrawable(d);
        if (imageChangeListener != null)
            imageChangeListener.changed((d == null));
    }

    @Override
    public void setImageResource(int id) {
        super.setImageResource(id);
    }

    public interface ImageChangeListener {
        // a callback for when a change has been made to this imageView
        void changed(boolean isEmpty);
    }

    public ImageChangeListener getImageChangeListener() {
        return imageChangeListener;
    }

    public void setImageChangeListener(ImageChangeListener imageChangeListener) {
        this.imageChangeListener = imageChangeListener;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = MeasureSpec.getSize(heightMeasureSpec);

        /**
         * if both width and height are set scale width first. modify in future if necessary
         */

        if (widthMode == MeasureSpec.EXACTLY || widthMode == MeasureSpec.AT_MOST) {
            scaleToWidth = true;
        } else if (heightMode == MeasureSpec.EXACTLY || heightMode == MeasureSpec.AT_MOST) {
            scaleToWidth = false;
        } else
            throw new IllegalStateException("width or height needs to be set to match_parent or a specific dimension");

        if (getDrawable() == null || getDrawable().getIntrinsicWidth() == 0) {
            // nothing to measure
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            return;
        } else {
            if (scaleToWidth) {
                int iw = this.getDrawable().getIntrinsicWidth();
                int ih = this.getDrawable().getIntrinsicHeight();
                int heightC = width * ih / iw;
                if (height > 0)
                    if (heightC > height) {
                        // dont let hegiht be greater then set max
                        heightC = height;
                        width = heightC * iw / ih;
                    }

                this.setScaleType(ScaleType.CENTER_CROP);
                setMeasuredDimension(width, heightC);

            } else {
                // need to scale to height instead
                int marg = 0;
                if (getParent() != null) {
                    if (getParent().getParent() != null) {
                        marg += ((RelativeLayout) getParent().getParent()).getPaddingTop();
                        marg += ((RelativeLayout) getParent().getParent()).getPaddingBottom();
                    }
                }

                int iw = this.getDrawable().getIntrinsicWidth();
                int ih = this.getDrawable().getIntrinsicHeight();

                width = height * iw / ih;
                height -= marg;
                setMeasuredDimension(width, height);
            }

        }
    }

}

（只需复制并粘贴此类即可，它与使用库相同）

然后在你的XML （你的父母必须是RelativeLayout）：

<!-- This is the UI of the class you created -->
<com.your.package.name.ScaleImageView 
    android:id="@+id/background"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentBottom="true"
    android:layout_alignParentEnd="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentStart="true"
    android:layout_alignParentTop="true"
    android:adjustViewBounds="true"
    android:scaleType="centerCrop"
    android:src="@drawable/food_wallpaper"
    tools:ignore="ContentDescription" />

android:scaleType="centerCrop"将图像裁剪到中心。 alignX属性使图像全屏显示。

Answer 2

而不是

android:src="@drawable/food_wallpaper"

试

keyword

Answer 3

尝试添加xml

android:scaleType="fitXY"

Android - 是否可以防止后台变得越来越小，但允许它自己调整大小以扩大规模？

3 个答案: