如何使用 public 静态字符串方法将上下文传递给 public class

Question

我有一个 public class 和一个 public static String 方法。我必须 getString() 并且我知道在那之前我必须提取 String 资源并传递 Context 但我不知道如何传递它。

另一个class使用public static String方法

代码示例：

public class StringUtil {

    public static String sumUp(int nr1, int nr2) {
        int sum = nr1 + nr2;
        String result;

        //all what is in ""  
        result =.getString(R.string.result) + sum;
        return result;

    }
}

ButtonListener class 使用 public static String 方法。代码：

public class ButtonListener extends MainActivity implements View.OnClickListener {
MainActivity activity;
EditText et1;
EditText et2;

public ButtonListener(MainActivity activity) {
    this.activity = activity;
}

@Override
public void onClick(View view) {

    switch (view.getId()){
        case R.id.sum:
            et1 = (EditText) activity.findViewById(R.id.nr1_edit_text);
            et2 = (EditText)activity.findViewById(R.id.nr2_edit_text);

            String nr1In = et1.getText().toString();
            String nr2In = et1.getText().toString();

            int nr1 = Integer.parseInt(nr1In);
            int nr2 = Integer.parseInt(nr2In);

            Intent intent = new Intent(activity, IntentActivity.class);
            intent.putExtra("result", StringUtil.sumUp(nr1, nr2));
            activity.startActivity(intent);
            break;
    }

}
}

IntentActivity class“getIntent”代码：

public class IntentActivity extends MainActivity{

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


       TextView textView = (TextView)findViewById(R.id.result);

        Intent intent = getIntent();

        String fResult = intent.getStringExtra("result");
        textView.setText(fResult);


    }
}

和 MainActivity 代码：

public class MainActivity extends AppCompatActivity {

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



        ButtonListener bl = new ButtonListener(this);

        Button sumUp= (Button)findViewById(R.id.sum_button);
        sumUp.setOnClickListener(bl);

    }
}

Answer 1

public class StringUtil {

    public static String sumUp(int nr1, int nr2, Context context){
        int sum = nr1 +nr2;
        String result;

        result = context.getString(R.string.result) + sum;
        return result;

        }
    }

并像这样使用它：

StringUtil.sumUp(1,2, this); // from Activity
StringUtil.sumUp(1,2, getContext()); // from Fragment

Answer 2

用这个替换你的 StringUtil class。

public class StringUtil {

    public static String sumUp(Context mContext, int nr1, int nr2){
        int sum = nr1 +nr2;
        String result;

        //all what is in ""  
        result = mContext.getString(R.string.result) + sum;
        return result;

    }
}

编辑

并从您的 ButtonListener activity.

调用此方法

intent.putExtra("result", StringUtil.sumUp(ButtonListener.this, nr1, nr2));

Answer 3

你有两种方法： 1.to 将其作为参数传递给您的方法：

          public static String sumUp(int nr1, int nr2 ,Context context){
            int sum = nr1 +nr2;
            String result;
            //all what is in ""  
            result = .getString(R.string.result) + sum;
            return result;              
            }

2.to 将上下文添加到 class 构造函数，然后您可以在您的方法中使用它：

public class StringUtil {
  Context context;

  public void StringUtil (Context context){
  this.context = context;
  }


    public static String sumUp(int nr1, int nr2){
    int sum = nr1 +nr2;
    String result;
    //all what is in ""  
    result = .getString(R.string.result) + sum;
    return result;

    }
}

如何使用 public 静态字符串方法将上下文传递给 public class

How to pass Context into public class with public static String method

string

android

getstring

编辑