android - 如何将位图缩放到屏幕大小？

Question

我想知道如何将位图缩放到屏幕高度和宽度？

谁能告诉我怎么做。

谢谢 蒙娜丽

Answer 1

试试这个解码位图:

其中imagefilepath是图片的路径名，它将在String中通过使用将其转换为文件

File photos= new File(imageFilePath);

photo 是 图片的文件名，现在您可以根据自己的要求设置高度和宽度。

public void main(){
    Bitmap bitmap = decodeFile(photo);
    bitmap = Bitmap.createScaledBitmap(bitmap,150, 150, true);
    imageView.setImageBitmap(bitmap);
} 

private Bitmap decodeFile(File f){
    try {
        //decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(new FileInputStream(f),null,o);              
        //Find the correct scale value. It should be the power of 2.
        final int REQUIRED_SIZE=70;
        int width_tmp=o.outWidth, height_tmp=o.outHeight;
        int scale=1;
        while(true){
            if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
                break;
            width_tmp/=2;
            height_tmp/=2;
            scale++;
        }

        //decode with inSampleSize
        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize=scale;
        return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
    } catch (FileNotFoundException e) {}
        return null;
}