Android 基于微调器值启动新活动导致意外停止
没有错误,但应用程序无法启动Android 基于微调器值启动新活动导致意外停止,android,spinner,buttonclick,Android,Spinner,Buttonclick,没有错误,但应用程序无法启动 public class MainActivity extends Activity { Button button1; @Override protected void onCreate(Bundle b) { super.onCreate(b); setContentView(R.layout.activity_main); Spinner spinner = (Spinner) findViewById(R.id.spinner1);
public class MainActivity extends Activity {
Button button1;
@Override
protected void onCreate(Bundle b) {
super.onCreate(b);
setContentView(R.layout.activity_main);
Spinner spinner = (Spinner) findViewById(R.id.spinner1);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,R.array.Class, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
Spinner nspinner = (Spinner) findViewById(R.id.spinner2);
ArrayAdapter<CharSequence> nadapter = ArrayAdapter.createFromResource(this,R.array.hour, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
nspinner.setAdapter(nadapter);
final String text = spinner.getSelectedItem().toString();
final String ntext = nspinner.getSelectedItem().toString();
button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (text.equals("IT6")){
Intent myIntent = new Intent(v.getContext(),
One.class);
startActivity(myIntent);
} else if (text.equals("IT8")){
Intent myIntent = new Intent(v.getContext(),
Two.class);
startActivity(myIntent);
}
}
});
公共类MainActivity扩展活动{
按钮1;
@凌驾
创建时受保护的void(束b){
super.onCreate(b);
setContentView(R.layout.activity_main);
微调器微调器=(微调器)findViewById(R.id.spinner1);
ArrayAdapter=ArrayAdapter.createFromResource(这个,R.array.Class,android.R.layout.simple\u微调器\u项);
setDropDownViewResource(android.R.layout.simple\u微调器\u下拉菜单\u项);
旋转器。设置适配器(适配器);
微调器nspinner=(微调器)findViewById(R.id.spinner2);
ArrayAdapter nadapter=ArrayAdapter.createFromResource(这个,R.array.hour,android.R.layout.simple\u微调器\u项);
setDropDownViewResource(android.R.layout.simple\u微调器\u下拉菜单\u项);
nspinner.setAdapter(nadapter);
最后一个字符串text=spinner.getSelectedItem().toString();
最后一个字符串ntext=nspinner.getSelectedItem().toString();
button1.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
if(文本等于(“IT6”)){
Intent myIntent=新的Intent(v.getContext(),
一级),;
星触觉(myIntent);
}else if(text.equals(“IT8”)){
Intent myIntent=新的Intent(v.getContext(),
二,班级),;
星触觉(myIntent);
}
}
});
如果它崩溃,那么您的日志猫中总是有输出,您应该发布这些输出。但是在这里,您似乎从未初始化按钮1
,因此,当您尝试在其上设置侦听器时,您将得到一个NPE
。您需要在setContentView()之后添加一些内容
button1 = (Button) findViewById(R.id.someId);