更改背景颜色时出现错误

Question

making an app that asks the user for their favorite color, then take them to a new Activity that uses that color as a background color and says something nice about them. but i dont why its crashing again and agian

heres the code

MainActivity.java

private TextView mtextview;
private EditText medittext;
private Button mbutton;

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

     mtextview = (TextView) findViewById(R.id.textView);
     medittext=(EditText)findViewById(R.id.editText);
    mbutton=(Button)findViewById(R.id.button);

    mbutton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String name =medittext.getText().toString();
            startStory(name);
        }

        private void startStory(String name) {
            Intent intent = new Intent(MainActivity.this,AnotherActivity.class);
            intent.putExtra("name",name);
            startActivity(intent);
        }
    });


}

}

AnotherActivity.java

public class AnotherActivity extends AppCompatActivity {

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

    final RelativeLayout mrelativelayout = (RelativeLayout) findViewById(R.id.activity_main);
    Intent intent   = getIntent();
    String name = intent.getStringExtra("name");
    mrelativelayout.setBackgroundColor(Color.parseColor(name));

}

}

Answer 1

I assume you are passing color name as "black", "blue", "skyblue" and likewise other color names.

But hope you know about the string parameters value supported by parseColor() method.

Supported formats are: #RRGGBB #AARRGGBB or one of the following names: 'red', 'blue', 'green', 'black', 'white', 'gray', 'cyan', 'magenta', 'yellow', 'lightgray', 'darkgray', 'grey', 'lightgrey', 'darkgrey', 'aqua', 'fuchsia', 'lime', 'maroon', 'navy', 'olive', 'purple', 'silver', 'teal'.

Answer 2

Change 1 :

first of all AnotherActivity add below code inside the OnCreate method.

final RelativeLayout mrelativelayout = (RelativeLayout) findViewById(R.id.activity_main) ;

because it give you NullPointerException .

Change 2 :

Instead of trying this

Editable name = medittext.getText();

use this way

 String name = medittext.getText().toString();

and pass that string to AnotherActivity via Intent .

Answer 3

Make sure that when you putExtra in the intent, you convert it to String. Currently you are just passing an Editable object and not String object to the intent

Example:

intent.putExtra("name",name.toString());

or better, change the type of name

String name = medittext.getText().toString();

Answer 4

Please, post your activity_main.xml and activity_another.xml. The problem is that there is not button with android:id="@+id/button" in your activity_main.xml, probably that's in activity_another.xml.