Android-創建一個僅包含所有圖像文件夾名稱的列表

Question

我被困在一個點，其中我的活動生成一個包含所有包含SD卡圖像的文件夾的縮略圖和名稱的列表。 1.我如何只過濾那些帶有圖像的文件夾？ 2.如何從文件夾中的第一個圖像獲取拇指圖像？

Answer 1

How do i filter only those folders with the images 

可以檢查文件的擴展名的文件夾中，看看他們是圖像類型的。

How do i get the thumb images from the first image in the folder 

壓縮文件到更小的尺寸通過使用以下

public Bitmap compressBitmap(String filePath, int requiredSize) 
{ 
    File file = new File(filePath); 
    if (file.exists()) 
    { 
     try 
     { 

      BitmapFactory.Options o = new BitmapFactory.Options(); 
      o.inJustDecodeBounds = true; 
      BitmapFactory.decodeFile(filePath, o); 

      // The new size we want to scale to 
      final int REQUIRED_SIZE = requiredSize; 

      // Find the correct scale value. It should be the power of 2. 
      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 *= 2; 
      } 

      // Decode with inSampleSize 
      BitmapFactory.Options o2 = new BitmapFactory.Options(); 
      o2.inSampleSize = scale; 
      return BitmapFactory.decodeStream(new FileInputStream(file), null, o2); 
     } 

     catch (FileNotFoundException e) 
     { 
      e.printStackTrace(); 
     } 

     return null; 
    } 

    return null; 
}