使用AlertDialog同步获取文本

Question

如何使用AlertDialog同步获取文本？例如，我想做这样的事情：

  public String GetTextDialog()
  {          
    final EditText text = new EditText(activity);

    // Gets the chat
    final AlertDialog.Builder dialog = new AlertDialog.Builder(activity);
    dialog.setView(text);
    dialog.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface arg0, int arg1) {
        }
    });
    dialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface arg0, int arg1) { 
        } 
    });

    // Display
    dialog.show();

    // Return text after dialog is complete
    return text.getText().toString();
  }

编辑：你认为这是一个更好的方法吗：

interface TextHandler 
{ 
    public String Title(); 
    public void HandleText(String text); 
}

public static boolean ShowTextDialog(
        String title,
        String defaultValue,
        final TextHandler posButton,
        final TextHandler negButton,
        final TextHandler neutButton,
        int width
        )
{
    // Check for already existing dialog
    if(showDialog) return false;
    showDialog = true;

    // Verify context
    if(context == null) 
    {
        Log.e("Crystal", "Screen::ShowTextDialog No Context!");
        showDialog = false;
        return false;
    }

    // Verify we have buttons
    if(neutButton == null)
    {
        if(posButton == null || negButton == null)
        {
            Log.e("Crystal", "Screen::ShowTextDialog Must supply both postive and negative buttons!");
            showDialog = false;
            return false;
        }
    }
    else
    {
        if(posButton != null || negButton != null)
        {
            Log.e("Crystal", "Screen::ShowTextDialog Can't have neutral button with other type!");
            showDialog = false;
            return false;
        }
    }

    // Create the dialog
    AlertDialog.Builder dialog = new AlertDialog.Builder(context);
    if(title != null) dialog.setTitle(title);

    // Create the chat
    final EditText text = new EditText(context);
    text.setSingleLine();
    if(defaultValue != null) text.setText(defaultValue);
    if(width != 0) text.setWidth((int)(width*context.getResources().getDisplayMetrics().density));

    // Add text to dialog
    dialog.setView(text);

    if(posButton != null)
    {
        dialog.setPositiveButton(posButton.Title(), new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface arg0, int arg1) {
                posButton.HandleText(text.getText().toString());
                showDialog = false;
            }
        });
    }

    if(negButton != null)
    {
        dialog.setNegativeButton(negButton.Title(), new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface arg0, int arg1) {
                negButton.HandleText(text.getText().toString());
                showDialog = false;
            }
        });
    }

    if(neutButton != null)
    {
        dialog.setNeutralButton(neutButton.Title(), new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface arg0, int arg1) {
                neutButton.HandleText(text.getText().toString());
                showDialog = false;
            }
        });
    }

    // Display
    dialog.show();

    return true;
}

并这样调用：

private void GetUsernameDialog()
{
    ShowTextDialog(
            "Enter Username",                                                   // Title
            username,                                                           // Default value
            new TextHandler()                                                   // Positive button
            {
                public String Title() { return "Ok"; }
                public void HandleText(String text) { SetUsername(text); }
            }, 
            new TextHandler()                                                   // Negative button
            {
                public String Title() { return "Cancel"; }
                public void HandleText(String text) { }
            }, 
            null,                                                               // Neutral button
            200                                                                 // Width
        );
}

Answer 1

你可以在一个带有 Looper 的替代线程中运行对话框，在对话框关闭时终止 Looper，让主 UI 线程等待另一个线程......但这是一个如此复杂的设计，上帝可能会杀死一只小猫，如果你就这么做。请问为什么需要同步数据访问？这只是为了方便，还是有设计原因？

如果它是关于访问对话框设置之前的状态，那么嵌套匿名类就是您的答案。您已经在上面的代码片段中获得了这些；它们可以自动访问嵌套函数的 final 变量以及嵌套类的成员。