java - 通过按钮使imageView可见和不可见

Question

我有三个 Activity ，每个 Activity 都有一个按钮。 Act1 与 btn1、Act2 与 btn2 以及 Act3 与 btn3 。我有另一个 Activity 作为 MainActivity，具有三个 imageView:ImageView1、imageView2 和 imageView3，所有这些最初都是不可见的。我希望这样当我在 act1 中单击 btn1 时，MainActivity 中的 imageView1 将可见，当再次单击 btn1 时，imageView1 将再次隐形。 imageView2 和 imageView3 也类似。 到目前为止我有这个代码:

Activity1

public class Activity1 extends AppCompatActivity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity1);

Button btn1 = (Button) findViewById(R.id.btn1);
btn1.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        String visibilityStr = PublicSharedPreferences.getDefaults("keyVisibility", getApplicationContext());

        if (visibilityStr != null) {
            if (visibilityStr.equals("0")) {
                Toast.makeText(act1.this, "it visibled", Toast.LENGTH_SHORT).show();
                visibilityStr = "1";
btn1.setImageResource(R.mipmap.img1);

            } else {
                visibilityStr = "0";
                Toast.makeText(act1.this, "it invisibled", Toast.LENGTH_SHORT).show();
btn1.setImageResource(R.mipmap.img2);

            }
        } else {
            visibilityStr = "1";
            Toast.makeText(act1.this, "it visibled", Toast.LENGTH_SHORT).show();
btn1.setImageResource(R.mipmap.img1);

        }

        PublicSharedPreferences.setDefaults("keyVisibility", visibilityStr, getApplicationContext());

    }
});
}





Activity2

public class Activity2 extends AppCompatActivity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity2);


Button btn1 = (Button) findViewById(R.id.btn2);
btn1.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        String visibilityStr = PublicSharedPreferences.getDefaults("keyVisibility", getApplicationContext());

        if (visibilityStr != null) {
            if (visibilityStr.equals("0")) {
                Toast.makeText(act2.this, "it visibled", Toast.LENGTH_SHORT).show();
btn2.setImageResource(R.mipmap.img1);

                visibilityStr = "1";
            } else {
                visibilityStr = "0";
                Toast.makeText(act2.this, "it invisibled", Toast.LENGTH_SHORT).show();
btn2.setImageResource(R.mipmap.img2);

            }
        } else {
            visibilityStr = "1";
            Toast.makeText(act2.this, "it visibled", Toast.LENGTH_SHORT).show();
btn2.setImageResource(R.mipmap.img1);

        }

        PublicSharedPreferences.setDefaults("keyVisibility", visibilityStr, getApplicationContext());

    }
});
}



Activity3

public class Activity3 extends AppCompatActivity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity3);

Button btn1 = (Button) findViewById(R.id.btn3);
btn1.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        String visibilityStr = PublicSharedPreferences.getDefaults("keyVisibility", getApplicationContext());

        if (visibilityStr != null) {
            if (visibilityStr.equals("0")) {
                Toast.makeText(act3.this, "it visibled", Toast.LENGTH_SHORT).show();
Btn3.setImageResource(R.mipmap.img1);

                visibilityStr = "1";
            } else {
                visibilityStr = "0";
                Toast.makeText(act3.this, "it invisibled", Toast.LENGTH_SHORT).show();
btn3.setImageResource(R.mipmap.img2);

            }
        } else {
            visibilityStr = "1";
            Toast.makeText(act3.this, "it visibled", Toast.LENGTH_SHORT).show();
btn3.setImageResource(R.mipmap.img1);

        }

        PublicSharedPreferences.setDefaults("keyVisibility", visibilityStr, getApplicationContext());
    }
});
}

具有三个 imageView 的 MainActivity:

    ImageView imgView1 = (ImageView) findViewById(R.id.imgView1);
String visibilityStr= PublicSharedPreferences.getDefaults("keyVisibility", getApplicationContext());

if (visibilityStr.equals("0"))
    imgView1.setVisibility(View.INVISIBLE);
else
    imgView1.setVisibility(View.VISIBLE);


ImageView imgView2 = (ImageView) findViewById(R.id.imgView2);
String visibilityStr= PublicSharedPreferences.getDefaults("keyVisibility", getApplicationContext());

if (visibilityStr.equals("0"))
    imgView2.setVisibility(View.INVISIBLE);
else
    imgView2.setVisibility(View.VISIBLE);



ImageView imgView3 = (ImageView) findViewById(R.id.imgView3);
String visibilityStr= PublicSharedPreferences.getDefaults("keyVisibility", getApplicationContext());

if (visibilityStr.equals("0"))
    imgView3.setVisibility(View.INVISIBLE);
else
    imgView3.setVisibility(View.VISIBLE);

它们工作得很好。但问题是，当我点击btn1时，MainActivity中的所有imageView都会改变(变得可见或不可见)，或者当我点击btn3时，所有imageView都会改变。我想要它，所以btn1只需更改imageView1，btn2只需更改imageView2和btn3只是更改imageView3，而不是更改所有 imageView 的按钮之一。我怎样才能做到这一点？哪部分代码是错误的？

Answer 1

问题是你只有 1key Preference 和所有 keyVisibility，所以当你点击任何按钮时，这个键会根据你的代码更改为 1 或 0

这里

ImageView imgView1 = (ImageView) findViewById(R.id.imgView1);
String visibilityStr1= PublicSharedPreferences.getDefaults("keyVisibility1", getApplicationContext());

if (visibilityStr1.equals("0"))
    imgView1.setVisibility(View.INVISIBLE);
else
    imgView1.setVisibility(View.VISIBLE);


ImageView imgView2 = (ImageView) findViewById(R.id.imgView2);
String visibilityStr2= PublicSharedPreferences.getDefaults("keyVisibility2", getApplicationContext());

if (visibilityStr2.equals("0"))
    imgView2.setVisibility(View.INVISIBLE);
else
imgView2.setVisibility(View.VISIBLE);



ImageView imgView3 = (ImageView) findViewById(R.id.imgView3);
`String visibilityStr3= PublicSharedPreferences.getDefaults("keyVisibility3",` `getApplicationContext());`

if (visibilityStr3.equals("0"))
    imgView3.setVisibility(View.INVISIBLE);
else
    imgView3.setVisibility(View.VISIBLE);

当然，您应该更改 act1、act2 和 act3 上的 keyVisibility