ImageView的是具有动态宽度的方？(ImageView be a square with dy

我有内部ImageViews一个GridView。我对他们有3对每一行。我可以正确设置与WRAP_CONTENT和scaleType = CENTER_CROP宽度，但我不知道如何设置的ImageView大小为正方形。这里就是我所做的到现在为止，这似乎是除了高度，那就是“静” OK：

imageView = new ImageView(context);     
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setLayoutParams(new GridView.LayoutParams(GridView.LayoutParams.WRAP_CONTENT, 300));

我正在做一个转接器内。

Answer 1:

最好的办法是继承ImageView自己，压倒一切措施通：

public class SquareImageView  extends ImageView {

  ...

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

    int width = getMeasuredWidth();
    setMeasuredDimension(width, width);
  }

  ...

}

Answer 2:

对方的回答工作正常。这仅仅是贝图西的溶液，以与正方形的宽度和高度的ImageView的相对于为xml充气布局的延伸。

创建一个类，说SquareImageView延伸ImageView的这个样子，

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);

        int width = getMeasuredWidth();
        setMeasuredDimension(width, width);
    }

}

现在，在你的XML做到这一点，

        <com.packagepath.tothis.SquareImageView
            android:id="@+id/Imageview"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent" />

如果您不需要在程序中动态创建的ImageView的，而是被固定在XML中，那么这个实施将是有益的。

Answer 3:

更简单：

public class SquareImageView extends ImageView {
    ...
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, widthMeasureSpec);
    }    
}

Answer 4:

一些以前的答案是完全足够了。我只是增加一个小的优化，既@Andro塞尔瓦和@ a.bertucci的解决方案，在这里：

这是一个很小的优化，但检查的宽度和高度都不同可以防止其他测量通。

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, widthMeasureSpec);

        int width = getMeasuredWidth();
        int height = getMeasuredHeight();

        // Optimization so we don't measure twice unless we need to
        if (width != height) {
            setMeasuredDimension(width, width);
        }
    }

}

Answer 5:

由指定的宽度的squareImageView：

public class SquareImageViewByWidth extends AppCompatImageView {

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

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

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

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

        int width= getMeasuredWidth();
        setMeasuredDimension(width, width);
    }

     ...
}

通过指定高度的squareImageView：

    public class SquareImageViewByHeight extends AppCompatImageView {

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

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

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

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

            int height = getMeasuredHeight();
            setMeasuredDimension(height, height);
        }

        ...
    }

通过dimentions最小的squareImageView：

public class SquareImageViewByMin extends AppCompatImageView {

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

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

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

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            int width = MeasureSpec.getSize(widthMeasureSpec);
            int height = MeasureSpec.getSize(heightMeasureSpec);
            int minSize = Math.min(width, height);
            setMeasuredDimension(minSize, minSize);
        }

       ...
    }

Answer 6:

对于那些寻找一个解决方案科特林：

class SquareImageView @JvmOverloads constructor(
        context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0, defStyleRes: Int = 0
) : ImageView(context, attrs, defStyleAttr, defStyleRes){
    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) = super.onMeasure(widthMeasureSpec, widthMeasureSpec)
}

Answer 7:

如果有人想的观点是不是正方形，而是在高度按比例调整（例如16/9或1/3），你可以做这样的：

@Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    heightMeasureSpec = MeasureSpec.makeMeasureSpec(getMeasuredWidth()/3, MeasureSpec.AT_MOST);
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

Answer 8:

这里都是不必要的调用其超类onMeasure 。下面是我的实现

@Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = MeasureSpec.getSize(heightMeasureSpec);
        int size = Math.min(width, height);
        setMeasuredDimension(size, size);
    }

文章来源: ImageView be a square with dynamic width?