我一直在尝试在我的主布局上制作两个按钮。这些按钮应该打开第二个布局,称为barcode_scanner.xml和vragen.xml
但是,只有第一个按钮才能打开扫描仪。第二个按钮不执行任何操作。
这是我当前来自 MainActivity.java 的代码
package com.kvprasad.zbarbarcodescanner;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
private Button scannerButton;
//@Override
//protected void onCreate(Bundle savedInstanceState) {
// super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_main);
// scannerButton = (Button) findViewById(R.id.scannerButton);
//scannerButton.setOnClickListener(new View.OnClickListener() {
// @Override
// public void onClick(View v) {
// Intent intent = new Intent(v.getContext(), BarcodeScanner.class);
// startActivity(intent);
// }
// });
//}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
//Barcodescanner knop
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button next = (Button) findViewById(R.id.scannerButton);
next.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), BarcodeScanner.class);
startActivityForResult(myIntent, 0);
}
});
}
//bovenbouw knop
public class AutoBodyActivity extends MainActivity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button next = (Button) findViewById(R.id.bovenbouw);
next.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), Vragen.class);
startActivityForResult(myIntent, 0);
}
});
}};
}
这是 onCreate 方法的具体部分:
@Override
//Barcodescanner knop
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button next = (Button) findViewById(R.id.scannerButton);
next.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), BarcodeScanner.class);
startActivityForResult(myIntent, 0);
}
});
}
//bovenbouw knop
public class AutoBodyActivity extends MainActivity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button next = (Button) findViewById(R.id.bovenbouw);
next.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), Vragen.class);
startActivityForResult(myIntent, 0);
}
});
}};
}
id 为“scannerButton”的按钮工作正常,但 id 为“bovenbouw”的按钮
我没有看到代码中有任何错误。可能出了什么问题?
最佳答案
您应该在 MainActivity.onCreate(..)
方法中声明这两个按钮
Button b1 = (Button) findViewById(R.id.b1);
Button b2 = (Button) findViewById(R.id.b2);
然后注册您的 onClick
监听器以打开新的 Activity。
对于您的第二个 Activity,您将有一个自己的类 SecondActivity
及其自己的 onCreate
方法来处理事务。
要打开第二个 Activity,您只需打开一个新的 Intent,如下所示
Intent intent = new Intent(this, SecondActivity.class);
startActivity(intent)
希望这有帮助:)
关于java - Android Studio 多个 onCreate 方法,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/37808301/