Android将位图保存在SD卡中

Question

i save the bitmap in sd card with the following code

String root = Environment.getExternalStorageDirectory().toString();
        File myDir = new File(root + "/saved_images");
        myDir.mkdirs();
        Random generator = new Random();
        int n = 10000;
        n = generator.nextInt(n);

        String fname = "Image" +".jpg";
       // String imageInSD1 = Environment.getExternalStorageDirectory().getAbsolutePath() +"/saved_images/" +  fname;
        File file = new File (myDir, fname);
       // if (file.exists ()) file.delete ();
        try {
            FileOutputStream out = new FileOutputStream(file);
            bitmap_profile1.compress(Bitmap.CompressFormat.JPEG, 100, out);
            out.flush();
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

its working fine but issue is this i am doing this in loop which run every 5 sec the image slowly slowly demage . i want to save the image only one time how can i check this if image is already in sd card then do not save the image i have only one name for image image change but its name remain same please tell i want to save the one image for only one time if bitmap value change then image save othervise image not save.

Answer 1

The function you're looking for is file.exists()

After creating your File file, go

if(!file.exists())
    try{...
        ....

Edit: Full code

String root = Environment.getExternalStorageDirectory().toString();
    File myDir = new File(root + "/saved_images");
    myDir.mkdirs();
    Random generator = new Random();
    int n = 10000;
    n = generator.nextInt(n);

    String fname = "Image" +".jpg";
    File file = new File (myDir, fname);
    if (file.exists ())    //  only try to save picture if it doesn't exist already
        try {
            FileOutputStream out = new FileOutputStream(file);
            bitmap_profile1.compress(Bitmap.CompressFormat.JPEG, 100, out);
            out.flush();
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }