java - 辅助 Activity 的问题无法从 texView 获取数据(已解决 - Oleg Golomoz 回答)

Question

您好，我的应用程序中有 2 个 Activity，我将从第一个 Activity 中获取数据并将其插入到第二个 Activity 中。

图片:我有 2 个日期选择器来选择日期范围，并将其保存在 texView 和 texView2 上。

代码:主要 Activity

selectDate = (Button) findViewById(R.id.button); 日期 = (TextView) findViewById(R.id.textView);

    selectDate2 = (Button) findViewById(R.id.button2);
    date2 = (TextView) findViewById(R.id.textView2);

    selectDate.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            calendar = Calendar.getInstance();
            year = calendar.get(Calendar.YEAR);
            month = calendar.get(Calendar.MONTH);
            dayOfMonth = calendar.get(Calendar.DAY_OF_MONTH);
            datePickerDialog = new DatePickerDialog(MainActivity.this,
                    new DatePickerDialog.OnDateSetListener() {
                        @Override
                        public void onDateSet(DatePicker datePicker, int year, int month, int day) {
                            date.setText("Entrada: "+day + "/" + (month + 1) + "/" + year);
                        }
                    }, year, month, dayOfMonth);
            datePickerDialog.show();
        }
    });


    selectDate2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            calendar2 = calendar2.getInstance();
            year2 = calendar2.get(Calendar.YEAR);
            month2 = calendar2.get(Calendar.MONTH);
            dayOfMonth2 = calendar2.get(Calendar.DAY_OF_MONTH);
            datePickerDialog2 = new DatePickerDialog(MainActivity.this,
                    new DatePickerDialog.OnDateSetListener() {
                        @Override
                        public void onDateSet(DatePicker datePicker, int year, int month, int day) {
                            date2.setText("Salida: "+day + "/" + (month + 1) + "/" + year);
                        }
                    }, year2, month2, dayOfMonth2);
            datePickerDialog2.show();
        }
    });

Activity 2:

package com.example.mand.consumirapirest;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

public class json extends AppCompatActivity {

    TextView tvJSON;
    TextView textView;

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

    public void setTextView() {
        tvJSON = (TextView) findViewById(R.id.tvJSON);
        textView = (TextView) findViewById(R.id.textView);

        String s = textView.getText().toString();

        tvJSON.setText(s);


        //String text = textView.getText().toString();
        //return text;
    }

    /*public String getText()
    {

    }*/
}

任何想法谢谢..!

Answer 1

第一个 Activity 中的某个位置 (MainActivity.java):

Button button = findViewById(R.id.button);

button.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent intent = new Intent(MainActivity.this, SecondActivity.class);

        // Pass some data
        // Key "DATE_KEY" is static field from SecondActivity
        intent.putExtra(DATE_KEY, "20.03.2019");

        startActivity(intent);
    }
});

在第二个 Activity (SecondActivity.java) 中:

public class SecondActivity extends AppCompatActivity {

    static final String DATE_KEY = "DATE_KEY";

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

        // Read passed data - String "20.03.2019"
        String date = getIntent().getStringExtra(DATE_KEY);
    }
}