问题描述

Android studio 报错:

 button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Intent intent = new Intent(this, DisplayMessageActivity.class);
                EditText editText = (EditText) findViewById(R.id.editTextTextPersonName);
                String message = editText.getText().toString();
                intent.putExtra(EXTRA_MESSAGE, message);
                startActivity(intent);
            }
        });

解决方案：

this前加MainActivity.

 button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, DisplayMessageActivity.class);
                EditText editText = (EditText) findViewById(R.id.editTextTextPersonName);
                String message = editText.getText().toString();
                intent.putExtra(EXTRA_MESSAGE, message);
                startActivity(intent);
            }
        });