保证图片长宽比的同时拉伸图片ImageView

按比例放大图片，不拉伸失真

import android.content.Context;
import android.util.AttributeSet;
import android.widget.ImageView;

public class AspectRatioImageView extends ImageView {

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

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

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

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = width * getDrawable().getIntrinsicHeight() / getDrawable().getIntrinsicWidth();
        setMeasuredDimension(width, height);
    }
}

也试试下面这个：

import android.content.Context;
import android.util.AttributeSet;
import android.widget.ImageView;

public class RatioImageView extends ImageView {

    private int originalWidth;
    private int originalHeight;

    public RatioImageView(Context context) {
        this(context, null);
    }

    public RatioImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public RatioImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void setOriginalSize(int originalWidth, int originalHeight) {
        this.originalWidth = originalWidth;
        this.originalHeight = originalHeight;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if (originalWidth > 0 && originalHeight > 0) {
            float ratio = (float) originalWidth / (float) originalHeight;

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

            if (width > 0) {
                height = (int) ((float) width / ratio);
            } else if (height > 0) {
                width = (int) ((float) height * ratio);
            }

            setMeasuredDimension(width, height);
        } else {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

}

import android.content.Context;
import android.net.Uri;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.widget.ImageView;

import com.laowch.githubtrends.R;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.display.SimpleBitmapDisplayer;
import com.nostra13.universalimageloader.core.listener.ImageLoadingListener;

/**
 * Created by lao on 3/4/14.
 */
public class AsyncImageView extends ImageView {


    String url;

    ImageLoadingListener imageLoadingListener;

    public AsyncImageView(final Context context) {
        super(context);
        init();
    }

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

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

    public void setImageLoadingListener(ImageLoadingListener listener) {
        this.imageLoadingListener = listener;
    }

    protected void init() {

    }

    public void loadImage(final String imageUrl) {
        if (imageUrl != null && url != null) {
            if (Uri.parse(imageUrl).getPath().equals(Uri.parse(url).getPath())) {
                return;
            }
        }
        url = imageUrl;
        executeLoadImage();
    }


    protected void executeLoadImage() {

        if (TextUtils.isEmpty(url)) {
            setImageResource(R.drawable.image_loading_resource);
        } else {

            DisplayImageOptions.Builder builder = new DisplayImageOptions.Builder()
                    .showImageOnLoading(R.drawable.image_loading_resource)
                    .cacheInMemory(true)
                    .cacheOnDisk(true)
                    .displayer(new SimpleBitmapDisplayer());

            DisplayImageOptions options = builder.build();
            ImageLoader.getInstance().displayImage(url, this, options, imageLoadingListener);
        }
    }
}

import android.content.Context;
import android.util.AttributeSet;
import android.widget.ImageView;

public class SquareImageView extends ImageView {


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

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

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

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        setMeasuredDimension(getMeasuredWidth(), getMeasuredWidth());
    }
}

import android.content.Context;
import android.util.AttributeSet;
import android.widget.RelativeLayout;

public class SquareLayout extends RelativeLayout {

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

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

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

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        setMeasuredDimension(getDefaultSize(0, widthMeasureSpec), getDefaultSize(0, heightMeasureSpec));

        heightMeasureSpec = widthMeasureSpec = MeasureSpec.makeMeasureSpec(getMeasuredWidth(), MeasureSpec.EXACTLY);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}

import android.content.Context;
import android.util.AttributeSet;
import android.util.SparseIntArray;
import android.view.View;
import android.widget.ImageView;

import java.util.ArrayList;

public class MultiStateView extends ImageView
        implements View.OnClickListener {

    private SparseIntArray mStateMap;
    private ArrayList<Integer> mStateList;
    private int mCurState;
    private IStateChangeListener mListener;

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


    public MultiStateView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

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

    private void init() {
        mStateMap = new SparseIntArray();
        mStateList = new ArrayList<>();
        setOnClickListener(this);
    }

    public void addStateAndImage(final int state, final int resId) {
        post(new Runnable() {
            @Override
            public void run() {
                mStateMap.put(state, resId);
                mStateList.add(state);
                if (mStateList.size() == 1) {
                    mCurState = state;
                    show(false);
                }
            }
        });
    }

    public void show(final int state) {
        if (mCurState == state) return;
        post(new Runnable() {
            @Override
            public void run() {
                mCurState = state;
                show(false);
            }
        });
    }

    private void show(boolean shouldNotify) {

        int id = mStateMap.get(mCurState);
        if (id == 0) return;


        setImageResource(id);

        if (shouldNotify && mListener != null) {
            mListener.onStateChange(mCurState);
        }
    }

    public void setOnStateChangeListener(IStateChangeListener listener) {
        this.mListener = listener;
    }

    @Override
    public void onClick(View v) {
        int size = mStateList.size();
        for (int i = 0; i < size; i++) {
            if (mCurState == mStateList.get(i)) {
                mCurState = mStateList.get((i + 1) % size);
                break;
            }
        }
        show(true);
    }


    public interface IStateChangeListener {
        void onStateChange(int state);
    }

}

用法：
实现implements MultiStateView.IStateChangeListener接口，重写onStateChange(int state)

......
mPlayModeView = (MultiStateView) findViewById(R.id.play_mode);
......
private void initPlayMode() {
        mPlayModeView.setOnStateChangeListener(this);
        mPlayModeView.addStateAndImage(SongManager.STATE_ALL, R.drawable.play_all);
        mPlayModeView.addStateAndImage(SongManager.STATE_RANDOM, R.drawable.play_random);
        mPlayModeView.addStateAndImage(SongManager.STATE_SINGLE, R.drawable.play_single);

        int state = SharedUtils.getInt(this, Constants.KEY_PLAY_MODE, SongManager.STATE_ALL);
        mPlayModeView.show(state);
    }
.......
@Override
    public void onStateChange(int state) {
        switch (state) {
            case SongManager.STATE_ALL:
                ToastUtils.show(this, "顺序播放");
                SharedUtils.saveInt(this, Constants.KEY_PLAY_MODE, state);
                SongManager.with(this).initPlayList();
                break;
            case SongManager.STATE_RANDOM:
                ToastUtils.show(this, "随机播放");
                SharedUtils.saveInt(this, Constants.KEY_PLAY_MODE, state);
                SongManager.with(this).initPlayList();
                break;
            case SongManager.STATE_SINGLE:
                ToastUtils.show(this, "单曲循环");
                SharedUtils.saveInt(this, Constants.KEY_PLAY_MODE, state);
                SongManager.with(this).initPlayList();
                break;
            case SongManager.STATE_PINGING:
                mPlayService.play();
                break;
            case SongManager.STATE_PAUSE:
                mPlayService.pause();
                break;
        }
    }