Question

我想在SD卡上的文件夹中保存多个图像，但在保存新图像时，之前的图像会被覆盖。如何在我的文件夹中保存多个图像？

    File mydirectory =  new File(Environment.getExternalStorageDirectory() + "/AppFolder");
    if(!mydirectory.exists()){

        mydirectory.mkdir();
    }

    if(mydirectory.exists()){
        try {
            File root = new File(Environment.getExternalStorageDirectory() +"/AppFolder");


            File sdImageMainDirectory = new File(root , "pic.png");
            outputFileUri = Uri.fromFile(sdImageMainDirectory);
            startCameraActivity();

        } catch (Exception e) {
            Toast.makeText(MainActivity.this, "Error occured. Please try again later.",Toast.LENGTH_SHORT).show();

            finish();
        }
    }
}

private void startCameraActivity() {
    // TODO Auto-generated method stub

    Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
    cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
    startActivityForResult(cameraIntent, 101);
}

Answer 1

您正在保存名称为pic.png的每个文件。

您每次都需要更改文件名。

编辑：

除了@David Xu的回答，如果你想每次都有唯一的名字，你可以在文件名的末尾附加一个unix时间戳，如下所示

dImageMainDirectory = new File(root, "pic_" + (System.currentTimeMillis() / 1000L) + ".png");

Answer 2

变化

File sdImageMainDirectory = new File(root , "pic.png");

到

File sdImageMainDirectory = null;
int i = 0;
do {
   sdImageMainDirectory = new File(root, "pic-" + i + ".png");
   i++;
} while (sdImageMainDirectory.exists());

Answer 3

您为每张照片使用相同的名称，这就是它被覆盖的原因

File sdImageMainDirectory = new File(root , "pic.png");

你将它们全部命名为pic.png

尝试开发像pic1.png，pic2.png这样的命名约定，或者你可以将png保存为当前时间戳的名称，如下所示：

//get timestamp into string
DateFormat df = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
Date today = Calendar.getInstance().getTime();        
String timeStamp = df.format(today);

File sdImageMainDirectory = new File(root , timeStamp + ".png");

Answer 4

您创建的每个文件都具有相同的名称。这是一个快速而肮脏的解决方案：

            try{
                File root = new File(Environment.getExternalStorageDirectory() +"/AppFolder");

                int i = 0;
                File sdImageMainDirectory = new File(root , "pic.png");
                while(sdImageMainDirectory.exists()){
                     i++
                     sdImageMainDirectory = new File(root , "pic" +i+ ".png");
                }
                outputFileUri = Uri.fromFile(sdImageMainDirectory);
                startCameraActivity();

             } catch (Exception e) {

保存到sdcard android时，图像被覆盖

4 个答案:

编辑：