縮放圖片 - 透過Matrix

我們從Device中取得的圖片資源很多是Drawable, 所以在縮放圖片前必須要轉成Bitmap才能繼續

public Bitmap DrawableToBitmap(Drawable drawableAPIcon)
{
    BitmapDrawable  bd = (BitmapDrawable)drawableAPIcon;
    Bitmap bitmapAPIcon = bd.getBitmap();

    return bitmapAPIcon;
}

原始的資源圖是大小不一的, 但Matrix，【數】矩陣，可以用於圖像處理的縮放、平移、旋轉等操作。

以下將所傳入的Bitmap調整為寬高：100x100

public Bitmap fixSize(Bitmap bitmapAPIcon)

{

    int iconWidth = 0;

    int iconHeight = 0;

    int newIconWidth = 100;

    int newIconHeight = 100;

    iconWidth = bitmapAPIcon.getWidth();    //先取得原Bitmap的寬

    iconHeight = bitmapAPIcon.getHeight(); //先取得原Bitmap的高

    float scaleIconWidth = ((float) newIconWidth) / iconWidth; //算出要調整的寬比例

    float scaleIconHeight = ((float) newIconHeight) / iconHeight; //算出要調整的高比例

    Matrix iconMatrix = new Matrix();

    iconMatrix.postScale(scaleIconWidth, scaleIconHeight); //經過比例調整

    Bitmap finalAPicon = Bitmap.createBitmap(bitmapAPIcon, 0, 0,iconWidth, iconHeight, iconMatrix, true); //建立新的Bitmap

    return finalAPicon;

}

調整為相同大小的圖後看起來整齊多了~

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查詢&開啟應用程式列表 - getInstalledApplications & getLaunchIntentForPackage (二)
http://bedingfield-tsots.blogspot.com/2012/03/getinstalledapplications.html