java - 在具有多个按钮的 fragment 中启动 Activity

Question

我对 Java 编程还比较陌生，我想打开一个带有多个不同 Activity 按钮的 fragment 。但是，我总是在以下位置收到错误(...已在...中定义):

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState)

此外，在其他变体中它不起作用，并且出现更多错误。

这是我的 fragment 的完整代码:

public DashboardFragment() {

}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment

    View rootView = inflater.inflate(R.layout.fragment_dashboard, container, false);

    ImageButton button = (ImageButton) rootView.findViewById(R.id.stundenplanbtn);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(getActivity(), Stundenplan.class);
            startActivity(intent);


        }
    });

    return rootView;
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment

    View rootView = inflater.inflate(R.layout.fragment_dashboard, container, false);

    ImageButton button2 = (ImageButton) rootView.findViewById(R.id.vertretungsbtn);
    button2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(getActivity(), Vertretungsplan.class);
            startActivity(intent);


        }
    });

    return rootView;
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment

    View rootView = inflater.inflate(R.layout.fragment_dashboard, container, false);

    ImageButton button2 = (ImageButton) rootView.findViewById(R.id.essenbtn);
    button2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(getActivity(), Essen.class);
            startActivity(intent);


        }
    });

    return rootView;
}
}

Answer 1

你真正想要的是这样的:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment

    View rootView = inflater.inflate(R.layout.fragment_dashboard, container, false);

    ImageButton button = (ImageButton) rootView.findViewById(R.id.stundenplanbtn);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(getActivity(), Stundenplan.class);
            startActivity(intent);


        }
    });

    ImageButton button2 = (ImageButton) rootView.findViewById(R.id.vertretungsbtn);
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(getActivity(), Vertretungsplan.class);
                startActivity(intent);


            }
        });

    return rootView;

}

此外，在 Android 特定上下文中，您实际上并不需要进行所有 ImageButton 转换等，因为您没有使用 ImageButton 类的任何特定方法，而且它扩展您可以简单使用的View类:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment

    View rootView = inflater.inflate(R.layout.fragment_dashboard, container, false);


    rootView.findViewById(R.id.stundenplanbtn).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(getActivity(), Stundenplan.class);
                startActivity(intent);


            }
        });

    rootView.findViewById(R.id.vertretungsbtn).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Intent intent = new Intent(getActivity(), Vertretungsplan.class);
                    startActivity(intent);


                }
            });

 return rootView;

}

请注意，这里唯一的事情不是创建按钮变量/引用，因此这只是一个小小的改进。但如果你现在感到困惑，请忽略并使用第一个。