我正在尝试创建一个具有多个不同 xml View /类的消息传递应用程序:
主菜单(MainActivity);
一个用于发送消息屏幕(SendMsg);
用于存储已发送消息(日志)。
在 SendMsg 中,我想将消息存储到一个名为 msgLog 的对象中,该对象是我在 MainActivity 中创建的。只是为了测试,我将 SendMsg 设置为在按下 SEND 按钮时显示 Logs 类,并且发送的消息确实出现在此处。
但是,它没有将其存储到我创建的 msgLog 变量中,因此我无法从 MainActivity 再次访问。
如何将其存储到变量中,以便在访问它时它始终存在?任何帮助将不胜感激。
============================================================
public class MainActivity extends AppCompatActivity {
Logs msgLog = new Logs();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void sendOnClick (View view){
Intent intent = new Intent("com.example.android.attone.SendMsg");
startActivity(intent);
}
public void logsOnClick (View view){
Intent intent = new Intent(this, Logs.class);
startActivity(intent);
}
}
============================================================
public class SendMsg extends AppCompatActivity {
EditText txtPhoneNo;
EditText txtMessage;
Button btnSend;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_send_msg);
txtPhoneNo = (EditText) this.findViewById(R.id.txtPhoneNo);
txtMessage = (EditText) this.findViewById(R.id.txtMessage);
btnSend = (Button) this.findViewById(R.id.btnSend);
btnSend.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)
{
// Get phone number and message sms
String phoneNo = txtPhoneNo.getText().toString();
String message = txtMessage.getText().toString();
Intent writeLog = new Intent(getApplicationContext(), Logs.class);
writeLog.putExtra("link", message);
startActivity(writeLog);
// If phone number and message is not empty
if (phoneNo.length() > 0 && message.length() > 0)
{
sendMessage(phoneNo, message);
}
else
{
Toast.makeText(getBaseContext(), "Please enter both number and message", Toast.LENGTH_LONG).show();
}
}
});
}
// Function send message sms
private void sendMessage(String phoneNo, String message)
{
try
{
SmsManager smsManager = SmsManager.getDefault();
smsManager.sendTextMessage(phoneNo, null, message, null, null);
Toast.makeText(getApplicationContext(), "SMS sent", Toast.LENGTH_LONG).show();
}
catch (Exception e)
{
Toast.makeText(getApplicationContext(), "SMS failed. Please try again!", Toast.LENGTH_LONG).show();
e.printStackTrace();
}
}
}
============================================================
public class Logs extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_logs);
String logging = getIntent().getStringExtra("link");
TextView textView = (TextView) findViewById(R.id.txtLog);
textView.setText(logging);
Button log2menu = (Button)findViewById(R.id.logToMenu);
log2menu.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(getApplicationContext(), MainActivity.class);
startActivity(intent);
}
});
}
}
最佳答案
您可以使用 SharedPreferences 来存储此类数据。 如果您不想在应用程序关闭后保存数据,您可以尝试的另一件事是将数据存储在单独类的静态变量中。
关于java - 如何将数据存储在对象而不是类中,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/37743546/