Android Studio 进度对话框未显示进度？

Question

我有一些代码（最后包含完整的方法），其中包括一个进度对话框。 问题是进度对话框没有显示任何进度（它没有从 0 移动到 100），它保持为零，没有移动，直到代码完成然后消失。所以它在正确的时间出现并在正确的时间被解雇，但它没有显示两者之间的进度。

这是我尝试增加对话框的部分。 intProgress 变量正在工作，我可以在日志中看到它从 0 递增到 100，那么为什么不会在进度对话框中显示呢？

                for(Animal animal : lstAnimals) {
                    i = i + 1;
                    animal.addToSqlLite(strTableName, animal, sqLiteDatabase);
                    int intProgress = (int) (((double) (i) / (double) lstAnimals.size()) * 100);
                    Log.d(TAG, "vvvv: " + "i = " + i + " total = " + lstAnimals.size() + " prog = " + intProgress);
                    progressDialog.setProgress(intProgress);
                }

这里有完整的方法：

    // fetches data from the server and copies it across to the sqlite database
public void fetchDataFromServerAndAddToSqlLite(ProgressBar progressBar, String strTableName, SQLiteDatabase sqLiteDatabase, Context context) {

//        progressBar.setVisibility(View.VISIBLE);
        ProgressDialog progressDialog = new ProgressDialog(context);
        progressDialog.setTitle("Wildgoosechase");
        progressDialog.setMessage("Downloading Animals...");
        progressDialog.setProgressStyle(progressDialog.STYLE_HORIZONTAL);
        progressDialog.setCancelable(false);
        progressDialog.setMax(100);
        progressDialog.setProgress(0);
        progressDialog.show();

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("https://xxxxxxxxxxxx.co.za/")
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        wildgoosechaseAPI myWildGooseChaseApi = retrofit.create(wildgoosechaseAPI.class);

        retrofit2.Call<List<Animal>> call = myWildGooseChaseApi.getAnimals();

        call.enqueue(new Callback<List<Animal>>() {
            @Override
            public void onResponse(Call<List<Animal>> call, Response<List<Animal>> response) {

                if(!response.isSuccessful()){
//                    progressBar.setVisibility(View.GONE);
                    progressDialog.dismiss();
                }

                List<Animal> lstAnimals = response.body();
                int i = 0;

                for(Animal animal : lstAnimals) {
                    i = i + 1;
                    animal.addToSqlLite(strTableName, animal, sqLiteDatabase);
                    int intProgress = (int) (((double) (i) / (double) lstAnimals.size()) * 100);
                    Log.d(TAG, "vvvv: " + "i = " + i + " total = " + lstAnimals.size() + " prog = " + intProgress);
                    progressDialog.setProgress(intProgress);
                }

//                progressBar.setVisibility(View.GONE);
                progressDialog.dismiss();


            }

            @Override
            public void onFailure(Call<List<Animal>> call, Throwable t) {
//                progressBar.setVisibility(View.GONE);
                progressDialog.dismiss();

            }
        });


    }

Answer 1

我认为缺少线程//线程用于更改进度值

    Thread thread = new Thread(new Runnable() {
        @Override
        public void run() {
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            setProgressValue(progress + 1);
        }
    });
    thread.start();

Answer 2

为什么不调用一个函数来做一件事

List<XXX> list;

public void fetchData() {
    //set start progressDialog

    fetchDataFromServer();
    saveDataToSQLite();
}


fetchDataFromServer() {
  ... 
  // Save response from server to list
}


public void saveDataToSQLite() {
  ...
  // Finish set progressDialog dimiss
}

Answer 3

一个可能的问题是您正在从非 UI 线程更新进度条。 您可以尝试将 setProgress 调用移动到 UI 线程中：

（假设您的方法在活动中）

YourActivity.this.runOnUiThread(new Runnable(){
   public void run(){
      progressDialog.setProgress(intProgress);
   }
});