关于Android中大量GUI更新编码的java概念（GUI处理程序）

Question

我有以下伪代码：

MySteps(){
  //Step A
  if (conditionA) {
    showwaitdialog(messageA); // shows wait dialog, so User knows app is running
    longrunnerA; // long running task, like downloading from internet.
    dismissdialog // closes the wait dialog.
  }
  //Step B
  if (conditionB && stepAfinished) { //real if not elseif
    showwaitdialog(messageB); // shows wait dialog
    longrunnerB; // long running task, like downloading from internet.
    dismissdialog
  }  
  //Step C
  if (conditionC && stepDfinished) { //real if not elseif
    showwaitdialog(messageC); // shows wait dialog
    longrunnerC; // long running task, like downloading from internet.
    dismissdialog
  }  
  if (!conditionA && !conditionB && !conditionC && allStepsfinished){
    startStepD();
  }
}

现在我想在我的Android应用程序中实现这个逻辑： 据我所知，我会将其编码如下（也是一种pseodocode），这会导致非常难看的代码：

HandlerA(){
  dismissDialog();
  if(ConditionB){
    showwaitdialog(messageB); // shows wait dialog
    new BackgroundTask {
      longrunnerB; // long running task, like downloading from internet.
      callHandlerB();
    }
  }
}

HandlerB(){
  dismissDialog();
  if(ConditionC){
    showwaitdialog(messageC); // shows wait dialog
    new BackgroundTask {
      longrunnerC; // long running task, like downloading from internet.
      callHandlerC();
    }
  }
}

HandlerC(){
  dismissDialog();
  if(!ConditionA && !ConditionB && !ConditionC){
    new BackgroundTask {
      startStepD();
    }
  }
}


MySteps(){ // not correct name, because it calls only step A. I cant see,that there is a lot other stuff triggered. 
  showwaitdialog(messageA); // shows wait dialog
  new BackgroundTask(){
    longrunnerA(); // long running task, like downloading from internet.
    call HandlerA();
  }
}

此代码分布在不同的位置，方法“MySteps”的名称错误，因为它只执行StepA

如何编写更简洁、更清晰的代码，这样我就有了一个方法MySteps（），它集中了整个逻辑，GUI更新将正常工作

*更新*

使用处理程序编码与使用GOTO语句编码类似。每个程序员都知道，我们应该避免GOTO语句。这就是为什么我在寻找更好的编码概念来实现上面的示例逻辑

Answer 1

解决方案

我认为这个伪代码可以使用AsyncTask

如果你需要的功能类似于下载文件，那么这可能是一个更好的选择

示例任务

public class ExampleTask extends AsyncTask<URL, Void, Boolean> {

    private ProgressDialog dialog;
    private Context context;
    private String message;

    public ExampleTask(Context context, String message)
    {
        this.context = context;
        this.dialog =new ProgressDialog(context);
        this.message = message;
    }

    protected Boolean doInBackground(URL... urls) {
        int count = urls.length;
        showDialog();

        for (int i = 0; i < count; i++) {

            // implement download target url[i]
            if (isCancelled()) return false;
        }

        dismissDialog();
        return true;
    }

    private void showDialog()
    {
        // show dialog
    }

    private void dismissDialog()
    {
        // dissmiss dialog
    }

    @Override
    protected void onPostExecute(Boolean aBoolean) {
        super.onPostExecute(aBoolean);

        //implements result handling
    }
}

执行任务

new ExampleTask(this, "message").execute(url1, url2, url3);