这是我的主要课程。我从用户输入中收到双打的地方。
public void onPayClick(View view){
Intent payIntent = new Intent(this, payActivity.class);
final EditText amountInput = (EditText) findViewById(R.id.amountInput);
final EditText yearInput = (EditText) findViewById(R.id.yearInput);
final EditText interestInput = (EditText) findViewById(R.id.interestInput);
double amountDouble = Double.parseDouble(amountInput.getText().toString());
double yearDouble = Double.parseDouble(yearInput.getText().toString());
double interestDouble = Double.parseDouble(interestInput.getText().toString());
payIntent.putExtra("amountDouble", amountDouble);
payIntent.putExtra("yearDouble", yearDouble);
payIntent.putExtra("interestDouble", interestDouble);
startActivity(payIntent);
}
这是我的第二项活动,在这里我想计算贷款,但我只想尝试打印amountDouble以查看它是否有效,它没有......
TextView printPay = (TextView) findViewById(R.id.printPay);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pay);
Bundle payData = getIntent().getExtras();
if(payData == null){
printPay.setText("Villa, þú verður að filla upp í alla reiti.");
return;
}
String amountDouble = payData.getString("amountDouble");
String yearDouble = payData.getString("yearDouble");
String interestDouble = payData.getString("interestDouble");
String sum1 = amountDouble;
printPay.setText(sum1);
}
每次单击payButton时,应用程序都会崩溃。
答案 0 :(得分:3)
从第1 Activity
开始,您可以直接在intent
添加这些值,因此您必须从intent
而不是bundle
获取这些数据。除此之外,您在类的顶部声明TextView
,因此它将 null 在onCreate(...)
之后在setContentView(R.layout.activity_pay);
内定义它。在第二次Activity
更改中
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pay);
TextView printPay = (TextView) findViewById(R.id.printPay);
String amountDouble = String.valueOf(getIntent().getDoubleExtra("amountDouble", 0.0));
String yearDouble = String.valueOf(getIntent().getDoubleExtra("yearDouble", 0.0);
String interestDouble = String.valueOf(getIntent().getDoubleExtra("interestDouble", 0.0);
String sum1 = amountDouble;
printPay.setText(sum1);
}