如何保存可见性android

Question

我试图保存我的卡片视图的可见性状态，起初我的视图已经消失，但如果用户按下按钮卡片视图将显示。有人可以帮助我并告诉我如何存储可见性，我在这个主题上找不到任何东西

非常感谢。

我尝试了 shardPrefs 但它不起作用

@Override
protected void onCreate(final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    cv1= (CardView) findViewById(R.id.cv1);
    cv2= (CardView) findViewById(R.id.cv2);
    cv3= (CardView) findViewById(R.id.cv3);
    cv4= (CardView) findViewById(R.id.cv4);
    cv5= (CardView) findViewById(R.id.cv5);
    cv6= (CardView) findViewById(R.id.cv6);
    cv7= (CardView) findViewById(R.id.cv7);
    cv8= (CardView) findViewById(R.id.cv8);
    cv9= (CardView) findViewById(R.id.cv9);

    AddBar = findViewById(R.id.AddBar);
    AddVoorraad =findViewById(R.id.AddVoorraad);

    AddBar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            clickcount = clickcount + 1;



            if (clickcount == 1) {

                cv1.setVisibility(View.VISIBLE);




            }

            if (clickcount == 2) {
                cv2.setVisibility(View.VISIBLE);
            }


            if (clickcount == 3) {
                cv3.setVisibility(View.VISIBLE);


            }
            if (clickcount == 4) {
                cv4.setVisibility(View.VISIBLE);


            }

            if (clickcount == 5) {
                cv5.setVisibility(View.VISIBLE);
            }


            if (clickcount == 6) {
                cv6.setVisibility(View.VISIBLE);


            }

            if (clickcount==7 ){
                cv7.setVisibility(View.VISIBLE);


            }

        }

    });

    AddVoorraad.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            clickcountV=clickcountV+1;

            if (clickcountV==1) {
                cv8.setVisibility(View.VISIBLE);


            }

            if (clickcount==2) {
                cv9.setVisibility(View.VISIBLE);
            }

        }
    });

    cv1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

        }
    });

    cv2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

        }
    });

    cv3.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

        }
    });


}

}`

Answer 1

尝试在条件下将每个CardView 存储在SharedPrefs 内。并在 CardView 初始化期间检索并设置。检查以下代码：

SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

int isVisible = sharedPreferences.getInt("cv1", View.GONE);
cv1.setVisibility(isVisible);
isVisible = sharedPreferences.getInt("cv2", View.GONE);
cv2.setVisibility(isVisible);
isVisible = sharedPreferences.getInt("cv3", View.GONE);
cv3.setVisibility(isVisible);
isVisible = sharedPreferences.getInt("cv4", View.GONE);
cv4.setVisibility(isVisible);
isVisible = sharedPreferences.getInt("cv5", View.GONE);
cv5.setVisibility(isVisible);
isVisible = sharedPreferences.getInt("cv6", View.GONE);
cv6.setVisibility(isVisible);
isVisible = sharedPreferences.getInt("cv7", View.GONE);
cv7.setVisibility(isVisible);
isVisible = sharedPreferences.getInt("cv8", View.GONE);
cv8.setVisibility(isVisible);
isVisible = sharedPreferences.getInt("cv9", View.GONE);
cv9.setVisibility(isVisible);

AddBar.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        clickcount = clickcount + 1;

        if (clickcount == 1) {

            cv1.setVisibility(View.VISIBLE);
            sharedPreferences.edit().putInt("cv1", View.VISIBLE).commit();
        }

        if (clickcount == 2) {
            cv2.setVisibility(View.VISIBLE);
            sharedPreferences.edit().putInt("cv2", View.VISIBLE).commit();
        }

        if (clickcount == 3) {
            cv3.setVisibility(View.VISIBLE);
            sharedPreferences.edit().putInt("cv3", View.VISIBLE).commit();
        }

        if (clickcount == 4) {
            cv4.setVisibility(View.VISIBLE);
            sharedPreferences.edit().putInt("cv4", View.VISIBLE).commit();
        }

        if (clickcount == 5) {
            cv5.setVisibility(View.VISIBLE);
            sharedPreferences.edit().putInt("cv5", View.VISIBLE).commit();
        }

        if (clickcount == 6) {
            cv6.setVisibility(View.VISIBLE);
            sharedPreferences.edit().putInt("cv6", View.VISIBLE).commit();
        }

        if (clickcount==7 ){
            cv7.setVisibility(View.VISIBLE);
            sharedPreferences.edit().putInt("cv7", View.VISIBLE).commit();
        }
    }
});

AddVoorraad.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        clickcountV=clickcountV+1;

        if (clickcountV==1) {
            cv8.setVisibility(View.VISIBLE);
            sharedPreferences.edit().putInt("cv8", View.VISIBLE).commit();
        }

        if (clickcountV==2) {
            cv9.setVisibility(View.VISIBLE);
            sharedPreferences.edit().putInt("cv9", View.VISIBLE).commit();
        }

    }
});

Answer 2

我不知道您具体尝试了什么，但如果您只想存储状态以备后用，您当然可以使用 SharedPreferences 来实现。您可以执行以下操作将状态保存为表示状态的字符串：

SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences();
SharedPreferences.Editor editor = prefs.edit();  
editor.putString("cv1_visibility", "VISIBLE");
editor.putString("cv2_visibility", "INVISIBLE");
editor.putString("cv3_visivility", "GONE");
...
editor.commit();

然后你可以像这样读取这些值：

SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences();
String cv1_state = prefs.getString("cv1_visibility", "NOT_FOUND");
String cv2_state = prefs.getString("cv2_visibility", "NOT_FOUND");
String cv3_state = prefs.getString("cv3_visibility", "NOT_FOUND");
...

然后根据活动开始时的状态适当地处理它。请注意，getString() 有一个 defValue 参数（第二个），这是在首选项不存在时返回的值。

编辑：您可以选择将它们存储为 int，但请注意其中一些常量不是 int。看看这个看看我的意思：https://developer.android.com/reference/android/view/View

Answer 3

您可以在配置更改（旋转）时从 onSaveInstanceState 中检索值，但是当您关闭应用程序（后退按钮）时，您需要从持久性存储中检索状态，例如共享首选项。