Question

我一直试图在我的主要布局上做两个buttong。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。第二个按钮没有任何作用。

这是我目前来自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

我没有看到代码中的任何错误。可能有什么不对？

Answer 1

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听众以打开新的活动。

对于您的第二项活动，您有一个自己的班级SecondActivity，并拥有自己的onCreate方法来处理这些事情。

要打开第二个Activity，你只需打开一个新的Intent

Intent intent = new Intent(this, SecondActivity.class);
startActivity(intent)

希望这有助于：）

Android Studio多个onCreate方法

1 个答案: