空指针Exception Android

Question

我将一个字符串从活动传递到另一个,它的工作,但如果我尝试打开活动而不传递字符串它抛出一个空指针异常,亲切的Assit

    Bundle gotBasket = getIntent().getExtras(); 
    gotPassenger= gotBasket.getString("passenger");
    gotStaffNumber= gotBasket.getString("clientcode");
    etPassenger.setText(""+ gotPassenger );
    etStaffNumber.setText("" + gotStaffNumber);

Answer 1

如果我尝试打开活动而不传递字符串它会抛出一个Null指针异常

对,因为你没有发送任何数据

在分配之前检查gotBasket是否为NULL

像这样:

Bundle gotBasket = getIntent().getExtras();
if(gotBasket != null){
    gotPassenger= gotBasket.getString("passenger");
    gotStaffNumber= gotBasket.getString("clientcode");
    etPassenger.setText(""+ gotPassenger );
    etStaffNumber.setText("" + gotStaffNumber);
}