Question

我目前正在尝试使用'toggle'类型的系统来切换按钮的文本，具体取决于它所代表的布尔值。

例如，当boolean RequestingLU为true时，我希望按钮说“停止”，如果为false，则说“开始”。

目前我把它放在onStart（）;这样每当我访问屏幕时它至少会更新，

public void onStart() {
    super.onStart();
    final SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
    final SharedPreferences.Editor editor = settings.edit();
    final Button StopButton = (Button) findViewById(R.id.StopButton);
    boolean RequestingLU = settings.getBoolean("RequestingLU", true);
    if (RequestingLU) {
        StopButton.setText(R.string.Stop_Button);
        StopButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                AlertDialog.Builder StopDialog = new AlertDialog.Builder(MainMenu.this);
                StopDialog.setTitle(R.string.Stop_Title);
                StopDialog.setMessage(R.string.Stop_Message);
                StopDialog.setPositiveButton(R.string.Stop_Button, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int id) {
                        editor.putBoolean("RequestingLU", false);
                        editor.apply();
                        Toast.makeText(MainMenu.this, "You have stopped the app", Toast.LENGTH_SHORT).show();
                        dialog.dismiss();
                    }
                });
                StopDialog.setNeutralButton(R.string.Negative_Button, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        //Closes box
                        dialog.dismiss();
                    }
                });
                StopDialog.create().show();
            }
        });
    }
    else {
        StopButton.setText(R.string.Start_Button);
        StopButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                editor.putBoolean("RequestingLU", true);
                editor.apply();
                Toast.makeText(MainMenu.this, "You have started the app", Toast.LENGTH_SHORT).show();
            }
        });
    }

}

我希望按钮正常运行，以便在用户按下“关闭”后立即应用更改。我怎样才能做到这一点？

Answer 1

我希望它对您有用 public void onStart（）{ super.onStart（）; final SharedPreferences settings = getSharedPreferences（PREFS_NAME，0）; final SharedPreferences.Editor editor = settings.edit（）; final Button StopButton =（Button）findViewById（R.id.StopButton）; boolean RequestingLU = settings.getBoolean（“RequestingLU”，true）;

    StopButton.setText(RequestingLU?R.string.Stop_Button:R.string.Start_Button);
    StopButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
           final boolean RequestingLUSwitch = settings.getBoolean("RequestingLU", true);
            if(RequestingLUSwitch) {
                AlertDialog.Builder StopDialog = new AlertDialog.Builder(MainMenu.this);
                StopDialog.setTitle(R.string.Stop_Title);
                StopDialog.setMessage(R.string.Stop_Message);
                StopDialog.setPositiveButton(R.string.Stop_Button, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int id) {
                        updatePreference(!RequestingLUSwitch);
                        Toast.makeText(MainMenu.this, "You have stopped the app", Toast.LENGTH_SHORT).show();
                        dialog.dismiss();
                    }
                });
                StopDialog.setNeutralButton(R.string.Negative_Button, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        //Closes box
                        dialog.dismiss();
                    }
                });
                StopDialog.create().show();
            }else{
                updatePreference(!RequestingLUSwitch);
                Toast.makeText(MainMenu.this, "You have started the app", Toast.LENGTH_SHORT).show();
            }
        }
    });


}

private void updatePreference(boolean requestingSwitch){
 SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
 SharedPreferences.Editor editor = settings.edit();
 editor.putBoolean("RequestingLU", !RequestingLUSwitch);
 editor.apply();
StopButton.setText(!RequestingLUSwitch ? R.string.Stop_Button : R.string.Start_Button);

}

Answer 2

将您的StopButton.setText()放入onClicks

立即更改按钮文本

2 个答案: