如何使用按钮将String值从一个活动传递到两个不同的活动？

Question

I would like to pass a value that I get from an EditText to two activities with a click of a button. I managed to pass the value to one activity, displaying it in textview and i would like to do the same to another activity but I'm not sure if switch case is the right method to use since there's only one button.

This is the codes for the first activity:

public class ProfInfo1 extends Activity {

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.profinfo1);


    final EditText et0 = (EditText) findViewById (R.id.et_name);
    final EditText et1 = (EditText) findViewById (R.id.et_age);
    final EditText et2 = (EditText) findViewById (R.id.et_height);
    final EditText et3 = (EditText) findViewById (R.id.et_weight);

    Button back = (Button) findViewById(R.id.btn_back1);
    back.setOnClickListener(new OnClickListener() {

    public void onClick(View v) {
        Intent a = new Intent(ProfInfo1.this, WelcomeActivity.class);
        startActivity(a);
    }

    });

    Button next = (Button) findViewById(R.id.btn_next1);
    next.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View v) {
        Intent intent=new Intent(ProfInfo1.this, ViewProf1.class);
        intent.putExtra("name", et0.getText().toString());
        intent.putExtra("age", et1.getText().toString());
        intent.putExtra("height", et2.getText().toString());
        intent.putExtra("weight", et3.getText().toString());
        startActivity(intent);
    }
});


}   
}

This is the second activity where the values are displayed:

public class ViewProf1 extends Activity {
EditText age, height, weight;
String a, h, w;
Float age1, height1, weight1;
float bmi, cal;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.profinfo1view);

    TextView nameView = (TextView) findViewById (R.id.view_name);
    nameView.setText("Hello " + getIntent().getExtras().getString("name") + ",");
    TextView ageView = (TextView) findViewById (R.id.view_age);
    ageView.setText("Age: " + getIntent().getExtras().getString("age"));
    TextView heightView = (TextView) findViewById (R.id.view_height);
    heightView.setText("Your current height is " + getIntent().getExtras().getString("height") + " m.");
    TextView weightView = (TextView) findViewById (R.id.view_weight);
    weightView.setText("Your current weight is " + getIntent().getExtras().getString("weight") + " kg.");

    a = getIntent().getExtras().getString("age");
    h = getIntent().getExtras().getString("height");
    w = getIntent().getExtras().getString("weight");

    age1 = Float.valueOf(a).floatValue();
    height1 = Float.valueOf(h).floatValue();
    weight1 = Float.valueOf(w).floatValue();

    //bmi calculation
    bmi = (float) (weight1/Math.pow(height1, 2));
    TextView showresult = (TextView) findViewById (R.id.view_bmi);
    showresult.setText("Your BMI is " + Float.valueOf(bmi) + ".");

    //cal intake calculation
    cal = (float) (((655 + (9.6 * weight1) + (1.8 * height1) - (4.7 * age1)) * 1.2) - 550);
    TextView showcal = (TextView) findViewById (R.id.view_cal);
    showcal.setText("Your ideal daily calories intake is " + Float.valueOf(cal) + ".");

    //next button
    Button next2 = (Button) findViewById (R.id.btn_next2);
    next2.setOnClickListener(new OnClickListener() {

    public void onClick(View v) {
        Intent a = new Intent(ViewProf1.this, FoodDiary.class);
        startActivity(a);
    }

    });

    //back button
    Button back2 = (Button) findViewById (R.id.btn_back2);
    back2.setOnClickListener(new OnClickListener() {

    public void onClick(View v) {
        Intent a = new Intent(ViewProf1.this, ProfInfo1.class);
        startActivity(a);
    }

    });


}

the third activity:

public class CompareWeight extends Activity {

EditText weight;
String w;
Float weight1;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.compareweight);

    TextView weightView = (TextView) findViewById (R.id.test);
    weightView.setText("Your previous weight is " + getIntent().getExtras().getString("weight") + " kg.");

    w = getIntent().getExtras().getString("weight");

    weight1 = Float.valueOf(w).floatValue();
}
}

I only want to pass the weight value to the third activity.

Answer 1

you can pass values to only one activity at a time.but if you want to pass weight value to third activity,then you can set it's value in first activity and retrieve in third activity. So basically I mean

1. Put values that you want to pass in SecondActivity with the help of putExtra.
2. Set the sharedPrefernce variable.
3. startActivity(intent);

Answer 2

您可以将值保存在“共享首选项”中，然后更新值。o单击“按钮”。这样，其他活动将可以使用这些值。

Answer 3

Use SharedPreferences in onPause for current Activity as below and send the data to other activities as below:

@Override
protected void onPause() 
{
  super.onPause(); 
  SharedPreferences preferences = getSharedPreferences("sharedPrefs", 0);
  SharedPreferences.Editor editor = preferences.edit();  
  editor.putString("SearchText",edt.getText().toString());
  editor.commit();

}

and in other two Activities, get the data from Shared Preferences as below:

 SharedPreferences preferences = getSharedPreferences("sharedPrefs", 0);
 String edtText = preferences.getString("SearchText","");

Answer 4

You can also get your string in the second activity like this :

Bundle extras = getIntent().getExtras();
        if(extras != null) {
            item = extras.getString("myitempassed");
        }

Answer 5

I don't see where in the code you are calling the third activity (CompareWeight).

When you start the CompareWeight activity, you can just pass in the weight value using intent extras like you did for the second activity.

If you don't have the weight value at that point, then you'll need to save it - @Avadhani Y has a good suggestion for using SharedPreferences. Or you can use a SQLite DB to store your values.

Answer 6

在startActivity之前使用PutExtra。

Answer 7

It is because in your Second Activity you just calling the Intent without passing any values in it,

In Second Activity

Replace the Intent

    Intent a = new Intent(ViewProf1.this, FoodDiary.class);
    startActivity(a); 

With this

    Intent a = new Intent(ViewProf1.this, FoodDiary.class);
    a.putExtra("weight", weight1);
    startActivity(a);