============问题描述============
<TextView
android:id="@+id/textview1"
android:layout_columnSpan="4"
android:layout_gravity="fill"
android:gravity="right"
android:text="0" />
public class MainActivity extends Activity {
Button one;
TextView text1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
one=(Button)findViewById(R.id.one);
text1=(TextView)findViewById(R.id.textview1);
setContentView(R.layout.activity_main);
}
public void clickone(View v){
double n=Double.parseDouble(text.getText().toString());
if(n!=0)
text1.setText(text1.getText()+"1");
else
text1.setText("1");
}
在主函数中各种方法都崩溃
============解决方案1============
one=(Button)findViewById(R.id.one);
text1=(TextView)findViewById(R.id.textview1);
这两句放setContentView(R.layout.activity_main);下面试试
)
)
