如何让android imageview方块？

Question

我ImageView在Android项目中使用了一个.

宽度:match_parent 高度:wrap_content

我将它缩放到了fill_XY,但图像还不是正方形......我该怎么办？

Answer 1

尝试通过扩展ImageView来创建自己的imageview.我是这样做的:

Icon.java文件

public class Icon extends ImageView {

public Icon(final Context context) {
    super(context);
}

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

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

@Override
protected void onMeasure(int width, int height) {
    super.onMeasure(width, height);
    int measuredWidth = getMeasuredWidth();
    int measuredHeight = getMeasuredHeight();
    if (measuredWidth > measuredHeight) {
        setMeasuredDimension(measuredHeight, measuredHeight);
    } else {
        setMeasuredDimension(measuredWidth, measuredWidth);

    }

}

}

xml文件

<com.mypackage.Icon
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:scaleType="centerCrop"
    android:src="@drawable/screen" />

Answer 2

方形图像的最佳方法是使用ConstraintLayout和constraintDimensionRatio而不给出修复高度/宽度.

  <android.support.constraint.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <ImageView
        android:id="@+id/image"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintDimensionRatio="H,1:1"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    </android.support.constraint.ConstraintLayout>

Answer 3

使用自定义视图并覆盖onMeasure()方法.

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

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

Answer 4

创建您自己的imageView. 这是一个例子

public class SquareImageView extends AppCompatImageView {
    public SquareImageView(Context context) {
        super(context);
    }

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

    public SquareImageView(Context context, @Nullable 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 size;
        if(MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY ^ MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.EXACTLY) {
            if (MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY)
                size = width;
            else
                size = height;
        }
        else
            size = Math.min(width, height);
        setMeasuredDimension(size, size);
    }
}