progressDialog.dismiss（）;之后沒有關閉progressDialog

Question

我有一個從文件中獲取字符串並將其放入名為username的String變量中的方法，因為從文件中讀取內容需要花費時間，我希望進度對話框出現直到功能結束，確實出現了preogress對話框，但並未關閉當我使用progressDialog.dismiss（）;時

這是代碼：

public String loadUserFromFile(){

    progressDialog = new ProgressDialog(this);
    progressDialog.setTitle("Please wait...");
    progressDialog.setMessage("Loading User");
    progressDialog.show();

    String username = "default";
    String fileName = "savedUserFile.txt";
    FileInputStream fis;
    try {
        fis = openFileInput(fileName);
        InputStreamReader inputStreamReader = new InputStreamReader(fis);
        BufferedReader br = new BufferedReader(inputStreamReader);
        username = br.readLine();
        br.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    username = username.replaceAll("\\s+","");
    progressDialog.dismiss();
    return username;
}

Answer 1

首先要確保對話框不為空。

 ProgressDialog mProgressDialog;
     mProgressDialog = new ProgressDialog(thisActivity);
            mProgressDialog.setCancelable(false);

 //If you want to show progress dialog
     public void showProgressDialog(String message) {
            if (mProgressDialog != null) {
                mProgressDialog.setMessage(message);
                mProgressDialog.show();
            }
        }

   //To dismiss progress dialog
    public void dismissProgressDialog() {
            if (mProgressDialog != null && mProgressDialog.isShowing()) {
                mProgressDialog.dismiss();
            }
        }

用法：

showProgressDialog（ “加載”）;

要么

dismissProgressDialog（）;