ui 更改的 onclicklistener 不会在第一次点击时更新

Question

我遇到了一个问题，我试图在单击事件时更改按钮的前景。前景仅在第一次点击后发生变化。

public void muteSoundClick(View view){
        playSound = preferences.getBoolean("playSound", true);

        if (playSound) {
            view.setForeground(getDrawable(R.drawable.foreground_padding_unmute));
            editor.putBoolean("playSound", false);
            editor.apply();
        }
        else {
            view.setForeground(getDrawable(R.drawable.foreground_padding_mute));
            editor.putBoolean("playSound", true);
            editor.apply();
        }
    }

我从 android SharedPrefernces 中检索一个变量，我用它来确定要使用的前景。

Answer 1

您似乎并没有真正编辑首选项。像这样。

SharedPreferences.Editor editor;

public void muteSoundClick(View view){
    playSound = preferences.getBoolean("playSound", true);

    if (playSound) {
        editor = sharedPreferences.edit();
        view.setForeground(getDrawable(R.drawable.foreground_padding_unmute));
        editor.putBoolean("playSound", false);
        editor.commit();
    }
    else {
        view.setForeground(getDrawable(R.drawable.foreground_padding_mute));
        editor.putBoolean("playSound", true);
        editor.apply();
    }
}

Answer 2

首先，您需要在 activity 开始时检查播放声音，以便按钮本身能够获得您第一次保存的内容，因此您需要这样的东西：

    playSound = preferences.getBoolean("playSound", true);

    if(playSound)
        button.setForeground(getDrawable(R.drawable.foreground_padding_mute));
    else

     button.setForeground(getDrawable(R.drawable.foreground_padding_unmute));

然后您可以使用您在问题中发布的相同方法处理点击

这里有一个示例 activity 总结一下：

public class SimpleActivity extends AppCompatActivity {

SharedPreferences preferences;
SharedPreferences.Editor editor;
boolean playSound;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_simple);

    preferences = PreferenceManager.getDefaultSharedPreferences(this);
    editor= PreferenceManager.getDefaultSharedPreferences(this).edit();
    Button button = findViewById(YourButtonID);
        playSound = preferences.getBoolean("playSound", true);

        if(playSound)
            button.setForeground(getDrawable(R.drawable.foreground_padding_mute));
        else
            button.setForeground(getDrawable(R.drawable.foreground_padding_unmute));

}


public void muteSoundClick(View view){
    playSound = preferences.getBoolean("playSound", true);

    if (playSound) {
        view.setForeground(getDrawable(R.drawable.foreground_padding_unmute));
        editor.putBoolean("playSound", false);
        editor.apply();
    }
    else {
        view.setForeground(getDrawable(R.drawable.foreground_padding_mute));
        editor.putBoolean("playSound", true);
        editor.apply();
    }
}

}

ui 更改的 onclicklistener 不会在第一次点击时更新

onclicklistener for ui change does not update on first click

android

buttonclick

sharedpreferences