ResultActivity

package baitap.gameloft.com.bai_tap_intent; import android.content.Intent; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.TextView; public class ResultActivity extends AppCompatActivity { TextView tv; Button btn_back; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_result); Intent intent_nhan = getIntent(); Bundle bun_nhan = intent_nhan.getBundleExtra("myPackage"); final int a = bun_nhan.getInt("soA"); final int b = bun_nhan.getInt("soB"); giaiPT(a,b); //---------------------------------------------------- btn_back = (Button)findViewById(R.id.btn_back); btn_back.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { MainActivity.change = 1; Intent intent = new Intent(ResultActivity.this, MainActivity.class); Bundle bun_di = new Bundle(); bun_di.putInt("soA",a); bun_di.putInt("soB",b); intent.putExtra("myPackage",bun_di); startActivity(intent); } }); } public void giaiPT(int a, int b){ tv = (TextView)findViewById(R.id.edt_kq); if (a == 0){ if (b == 0) { tv.setText(tv.getText().toString() + "Phuong trinh vo so nghiem"); return; } else { tv.setText(tv.getText().toString() + "Phuong trinh vo nghiem"); return; } } else { tv.setText(tv.getText().toString()+"Phuong trinh co nghiem la:" + String.valueOf((float)-b/a)); return; } } }