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Android:无法更改片段中按钮的背景(可绘制)

android-fragments android java

Maarten · 技术社区 · 6 年前

我有以下问题无法解决:

我正在构建一个包含多个片段的android应用程序。在第二个片段上有一个按钮,每次按下该按钮时,需要更改其背景(即可绘制)。在我添加更多逻辑之前,我希望这能起作用,但我无法让它起作用。非常感谢您的帮助!

round\u按钮\u f2\u减少。xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list
    xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="oval">
            <solid android:color="@color/colorButtonF1Decrease" />
        </shape>
    </item>
    <item
        android:drawable="@drawable/ic_trending_down_white_24px"
        android:gravity="center" />
</layer-list>

round\u按钮\u f2\u增加。xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="oval">
            <solid android:color="@color/colorButtonF1Increase" />
        </shape>
    </item>
    <item
        android:drawable="@drawable/ic_trending_up_white_24px"
        android:gravity="center" />
</layer-list>

碎片2。xml

<?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"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/f2_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="Placeholder"
        android:textAlignment="center"
        android:textSize="40sp"
        android:textStyle="bold"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/f2_button"
        android:layout_width="56dp"
        android:layout_height="56dp"
        android:layout_marginBottom="24dp"
        android:layout_marginEnd="24dp"
        android:elevation="2dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

</android.support.constraint.ConstraintLayout>

碎片二。JAVA

import android.graphics.drawable.Drawable;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.Toast;

public class FragmentTwo extends Fragment {
    private static final String TAG = "FragmentTwo";

    private Button mbtnSort;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_two, container, false);

        mbtnSort = view.findViewById(R.id.f2_button);
        mbtnSort.setBackground(getResources().getDrawable(R.drawable.round_button_f2_decrease));
        mbtnSort.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Drawable btnBackground = mbtnSort.getBackground();
                if (btnBackground.equals(getResources().getDrawable(R.drawable.round_button_f2_decrease))) {
                    Toast.makeText(getActivity(), "IF", Toast.LENGTH_LONG).show();
                    mbtnSort.setBackground(getResources().getDrawable(R.drawable.round_button_f2_increase));
                } else {
                    Toast.makeText(getActivity(), "ELSE", Toast.LENGTH_LONG).show();
                    mbtnSort.setBackground(getResources().getDrawable(R.drawable.round_button_f2_decrease));
                }
            }
        });
        return view;
    }
}

3 回复 | 直到 6 年前

Taranmeet Singh 6 年前

使用

mbtnSort.setBackground(R.drawable.round_button_f2_decrease);

Maarten 6 年前

现在它可以工作了:

public class FragmentThree extends Fragment {
    private static final String TAG = "FragmentThree";

    private Button mbtnSort;
    private boolean mbtnPressed = false;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_three, container, false);

        mbtnSort = view.findViewById(R.id.f3_button);
        mbtnSort.setBackgroundResource(R.drawable.round_button_f2_decrease);
        mbtnSort.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mbtnPressed == true) {
                    Toast.makeText(getActivity(), "IF", Toast.LENGTH_LONG).show();
                    mbtnSort.setBackgroundResource(R.drawable.round_button_f2_decrease);
                    mbtnPressed = false;
                } else {
                    Toast.makeText(getActivity(), "ELSE", Toast.LENGTH_LONG).show();
                    mbtnSort.setBackgroundResource(R.drawable.round_button_f2_increase);
                    mbtnPressed = true;
                }
            }
        });
        return view;
    }
}

Hassan Badawi 6 年前

我想我理解你在不改变背景的情况下试图解决你的问题你的背景问题本身

我找了你很多东西,想知道如何回到地面,并用你的round\u button\u f2\u decrease检查它。xml

所以这很难

如果您使用flag或其他东西进行此操作,现在将对您的问题有帮助

我发现这可能有用 Comparing two drawables in android

还有这个 Comparing resources within two drawables