Question

我正在开发一个应用程序，在那里我制作了一个“自定义键盘”，你可以“输入”扑克牌。我把那个“键盘”变成了一个片段，我试图让它出现在我的主要活动中，但它不会显示出来。我到处寻找但找不到解决方案。你可能会说，我对android很新，特别是片段。任何帮助将不胜感激。

代码：

MainActivity.java：

package com.example.cribbage2;

import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;

public class MainActivity extends FragmentActivity implements 
CardKeyboardFrag.CardTransfer{

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Fragment newFragment = new Fragment();
    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();

    transaction.add(R.id.fragment_container, newFragment);
    transaction.addToBackStack(null);

    transaction.commit();
}

@Override
public void onCardSelected(int card) {
    //do stuff with int here
}
}

activity_main.xml中：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.cribbage2.MainActivity">

<FrameLayout
    android:id="@+id/fragment_container"
    android:layout_width="368dp"
    android:layout_height="495dp"
    app:layout_constraintTop_toTopOf="parent"
    android:layout_marginTop="8dp"
    app:layout_constraintBottom_toBottomOf="parent"
    android:layout_marginBottom="8dp"
    android:layout_marginLeft="8dp"
    app:layout_constraintLeft_toLeftOf="parent"
    android:layout_marginRight="8dp"
    app:layout_constraintRight_toRightOf="parent">

</FrameLayout>

CardKeyboardFrag.java

package com.example.cribbage2;

import android.app.Activity;
import android.app.Fragment;
import android.content.Context;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;


public class CardKeyboardFrag extends android.support.v4.app.Fragment implements View.OnClickListener {

CardTransfer mCallback;

public interface CardTransfer {
    void onCardSelected(int card);
}

@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.card_keyboard_frag, container, false);

    //region buttonAssignments
    Button one = (Button) getView().findViewById(R.id.buttonA);
    one.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(1);
        }
    });
    Button two = (Button) getView().findViewById(R.id.button2);
    two.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(2);
        }
    });
    Button three = (Button) getView().findViewById(R.id.button3);
    three.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(3);
        }
    });
    Button four = (Button) getView().findViewById(R.id.button4);
    four.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(4);
        }
    });
    Button five = (Button) getView().findViewById(R.id.button5);
    five.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(5);
        }
    });
    Button six = (Button) getView().findViewById(R.id.button6);
    six.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(6);
        }
    });
    Button seven = (Button) getView().findViewById(R.id.button7);
    seven.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(7);
        }
    });
    Button eight = (Button) getView().findViewById(R.id.button8);
    eight.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(8);
        }
    });
    Button nine = (Button) getView().findViewById(R.id.button9);
    nine.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(9);
        }
    });
    Button ten = (Button) getView().findViewById(R.id.button10);
    ten.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(10);
        }
    });
    Button eleven = (Button) getView().findViewById(R.id.buttonJ);
    eleven.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(11);
        }
    });
    Button twelve = (Button) getView().findViewById(R.id.buttonQ);
    twelve.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(12);
        }
    });
    Button thirteen = (Button) getView().findViewById(R.id.buttonK);
    thirteen.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(13);
        }
    });
    Button delete = (Button) getView().findViewById(R.id.buttonD);
    delete.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(14);
        }
    });
    Button buttonGo = (Button) getView().findViewById(R.id.buttonG);
    buttonGo.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            buttonClicked(15);
        }
    });
    //endregion

    return view;
}

@Override
public void onAttach(Context context) {
    super.onAttach(context);

    try {
        mCallback = (CardTransfer) context;
    } catch (ClassCastException e) {
        throw new ClassCastException(context.toString() + " must implement CardTransfer");
    }
}


@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.buttonA:
            buttonClicked(1);
            break;

        case R.id.button2:
            buttonClicked(2);
            break;

        case R.id.button3:
            buttonClicked(3);
            break;

        case R.id.button4:
            buttonClicked(4);
            break;

        case R.id.button5:
            buttonClicked(5);
            break;

        case R.id.button6:
            buttonClicked(6);
            break;

        case R.id.button7:
            buttonClicked(7);
            break;

        case R.id.button8:
            buttonClicked(8);
            break;

        case R.id.button9:
            buttonClicked(9);
            break;

        case R.id.button10:
            buttonClicked(10);
            break;

        case R.id.buttonJ:
            buttonClicked(11);
            break;

        case R.id.buttonQ:
            buttonClicked(12);
            break;

        case R.id.buttonK:
            buttonClicked(13);
            break;

        case R.id.buttonD:
            buttonClicked(14);
            break;

        case R.id.buttonG:
            buttonClicked(15);
            break;
    }
}

public void buttonClicked(int num){
    mCallback.onCardSelected(num);
}
}

card_keyboard_frag.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                xmlns:app="http://schemas.android.com/apk/res-auto">


<TextView
    android:id="@+id/textView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="16dp"
    android:text="Cards"
    android:textAlignment="center"
    android:textSize="30sp"/>

<GridLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentStart="true"
    android:layout_marginBottom="8dp"
    android:columnCount="3"
    android:rowCount="5">

    <Button
        android:id="@+id/buttonK"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="King"/>

    <Button
        android:id="@+id/buttonD"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="Delete"/>

    <Button
        android:id="@+id/buttonG"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="Go!"/>

    <Button
        android:id="@+id/button10"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="10"/>

    <Button
        android:id="@+id/buttonJ"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="Jack"/>

    <Button
        android:id="@+id/buttonQ"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="Queen"/>

    <Button
        android:id="@+id/button7"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="7"/>

    <Button
        android:id="@+id/button8"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="8"/>

    <Button
        android:id="@+id/button9"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="9"/>

    <Button
        android:id="@+id/button4"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="4"/>

    <Button
        android:id="@+id/button5"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="5"/>

    <Button
        android:id="@+id/button6"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="6"/>

    <Button
        android:id="@+id/buttonA"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="Ace"/>

    <Button
        android:id="@+id/button2"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="2"/>

    <Button
        android:id="@+id/button3"
        android:layout_width="120dp"
        android:layout_height="50dp"
        android:text="3"/>
</GridLayout>

</RelativeLayout>

提前再次感谢！

Answer 1

您必须创建片段的实例 - 不仅是通用片段。喜欢：

CardKeyboardFrag cardFrag = new CardKeyboardFrag();

和

transaction.add(R.id.fragment_container, cardFrag);

碎片没有出现

1 个答案: