调整图片大小适应屏幕的imagview类

最新推荐文章于 2024-10-15 15:10:27 发布

原创最新推荐文章于 2024-10-15 15:10:27 发布 · 718 阅读

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本文介绍了一个自定义的Android ImageView组件——MyImageView，该组件能够自动计算图片的显示尺寸，确保图片在保持原始宽高比例的同时充满整个ImageView。通过重写onMeasure方法并调整图片的测量规格来实现这一功能。

package com.test.android.imageview;

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

public class MyImageView extends ImageView {

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

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

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

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

		final int width = MeasureSpec.getSize(widthMeasureSpec);

		Drawable d = getDrawable();
		Bitmap b = ((BitmapDrawable) d).getBitmap();

		float scale = width / (float) b.getWidth();
		int height = (int) (scale * b.getHeight());

		final int exactWidth = MeasureSpec.makeMeasureSpec(width,
				MeasureSpec.EXACTLY);
		final int exactHeight = MeasureSpec.makeMeasureSpec(height,
				MeasureSpec.EXACTLY);

		super.onMeasure(exactWidth, exactHeight);
	}
}