Android中缩放图片的一个方法

最新推荐文章于 2018-11-11 08:02:25 发布

转载最新推荐文章于 2018-11-11 08:02:25 发布 · 641 阅读

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本文介绍了一种使用Android平台下的Bitmap对象进行图片缩放的方法。通过计算目标宽度和高度的比例来调整图片尺寸，并利用Matrix对象完成缩放操作。最终将处理后的Bitmap转换为Drawable对象以便在应用程序中使用。

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public static Drawable
 resizeImage(Bitmap bitmap, int w, int h)
 {

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                //
 load the origial Bitmap

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                Bitmap
 BitmapOrg = bitmap;

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                int width
 = BitmapOrg.getWidth();

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                int height
 = BitmapOrg.getHeight();

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                int newWidth
 = w;

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                int newHeight
 = h;

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                //
 calculate the scale

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                float scaleWidth
 = ((float)
 newWidth) / width;

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                float scaleHeight
 = ((float)
 newHeight) / height;

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                //
 create a matrix for the manipulation

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                Matrix
 matrix = new Matrix();

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                //
 resize the Bitmap

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                matrix.postScale(scaleWidth,
 scaleHeight);

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                //
 if you want to rotate the Bitmap

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                //
 matrix.postRotate(45);

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                //
 recreate the new Bitmap

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                Bitmap
 resizedBitmap = Bitmap.createBitmap(BitmapOrg, 0, 0,
 width,

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                                height,
 matrix, true);

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                //
 make a Drawable from Bitmap to allow to set the Bitmap

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                //
 to the ImageView, ImageButton or what ever

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                return new BitmapDrawable(resizedBitmap);

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        }