java - 在新 Activity 中查看和下载壁纸时遇到问题

Question

我正在创建一个壁纸应用程序。我使用毕加索完成了类别和每个类别内的壁纸。现在我尝试创建一个新 Activity 来使用毕加索查看和下载任何壁纸。但是编码后，当我单击壁纸时，新 Activity 永远不会打开。 LogCat 上也没有显示相关错误。请帮忙!

这是 list :

    <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="me.umarkhan.walldeck">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.SET_WALLPAPER"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/FullScreenTheme">
        <activity android:name=".ViewWallpaper"></activity>
        <activity android:name=".ListWallpaper" />
        <activity
            android:name=".HomeActivity"
            android:label="@string/title_activity_home"
            android:theme="@style/FullScreenTheme" />
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

XML 代码:

    <?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout 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:id="@+id/rootLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/white"
    tools:context="me.umarkhan.walldeck.ViewWallpaper">

    <com.google.android.material.appbar.AppBarLayout
        android:id="@+id/app_bar_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <com.google.android.material.appbar.CollapsingToolbarLayout
            android:id="@+id/collapsing"
            android:fitsSystemWindows="true"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            app:contentScrim="?attr/colorPrimary"
            app:expandedTitleTextAppearance="@android:color/transparent"
            android:layout_width="match_parent"
            android:layout_height="350dp">

            <ImageView
                android:id="@+id/imageThumb"
                android:contentDescription="WallDeck Wallpaper"
                android:scaleType="centerCrop"
                android:layout_width="match_parent"
                android:layout_height="match_parent"/>

            <androidx.appcompat.widget.Toolbar
                android:id="@+id/toolbar"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:layout_collapseMode="pin"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"></androidx.appcompat.widget.Toolbar>

        </com.google.android.material.appbar.CollapsingToolbarLayout>


    </com.google.android.material.appbar.AppBarLayout>

    <androidx.core.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="590dp"
        android:clipToPadding="false"
        app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior"
        tools:layout_editor_absoluteY="352dp">

        <androidx.cardview.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="16dp"
            app:cardElevation="10dp"
            app:cardUseCompatPadding="true">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="12dp"
                    android:padding="12dp"
                    android:text="Wallpaper description"
                    android:textSize="20sp"/>

            </LinearLayout>

        </androidx.cardview.widget.CardView>

    </androidx.core.widget.NestedScrollView>

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/fabWallpaper"
        android:layout_marginRight="30dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_terrain_black_24dp"
        android:elevation="6dp"
        app:pressedTranslationZ="12dp"
        app:layout_anchor="@id/app_bar_layout"
        app:layout_anchorGravity="bottom|right|end"
        android:backgroundTint="@android:color/white"/>

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/fabDownload"
        android:layout_marginLeft="30dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_file_download_black_24dp"
        android:elevation="6dp"
        app:pressedTranslationZ="12dp"
        app:layout_anchor="@id/app_bar_layout"
        app:layout_anchorGravity="bottom|left|start"
        android:backgroundTint="@android:color/white"/>


</androidx.coordinatorlayout.widget.CoordinatorLayout>

SaveImageHelper类

包 me.umarkhan.walldeck.Helper;

import android.app.AlertDialog;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.provider.MediaStore;
import android.widget.Toast;
import com.squareup.picasso.Picasso;
import com.squareup.picasso.Target;
import java.lang.ref.WeakReference;

public class SaveImageHelper implements Target {

    private Context context;
    private WeakReference<AlertDialog> alertDialogWeakReference;
    private WeakReference<ContentResolver> contentResolverWeakReference;
    private String name;
    private String desc;

    public SaveImageHelper(Context context, AlertDialog alertDialog, ContentResolver contentResolver, String name, String desc) {
        this.context = context;
        this.alertDialogWeakReference =new WeakReference<AlertDialog>(alertDialog);
        this.contentResolverWeakReference =new WeakReference<ContentResolver>(contentResolver);
        this.name = name;
        this.desc = desc;
    }

    @Override
    public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
        ContentResolver r = contentResolverWeakReference.get();
        AlertDialog alertDialog = alertDialogWeakReference.get();
        if (r != null)
            MediaStore.Images.Media.insertImage(r,bitmap,name,desc);
        alertDialog.dismiss();
        Toast.makeText(context,"Download Successful", Toast.LENGTH_SHORT).show();

        //Open Gallery After Download
        Intent intent = new Intent();
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        context.startActivity(Intent.createChooser(intent,"View Picture"));
    }

    @Override
    public void onBitmapFailed(Drawable errorDrawable) {

    }

    @Override
    public void onPrepareLoad(Drawable placeHolderDrawable) {

    }
}

ViewWallpaper类

包 me.umarkhan.walldeck;

import android.Manifest;
import android.app.AlertDialog;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.coordinatorlayout.widget.CoordinatorLayout;
import androidx.core.app.ActivityCompat;
import com.google.android.material.appbar.CollapsingToolbarLayout;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.squareup.picasso.Picasso;
import java.lang.annotation.Annotation;
import java.lang.annotation.ElementType;
import com.squareup.picasso.Target;
import java.util.UUID;
import dmax.dialog.SpotsDialog;
import me.umarkhan.walldeck.Common.Common;
import me.umarkhan.walldeck.Helper.SaveImageHelper;

public class ViewWallpaper extends AppCompatActivity {

    CollapsingToolbarLayout collapsingToolbarLayout;
    FloatingActionButton floatingActionButton,fabDownload;
    ImageView imageView;
    CoordinatorLayout rootLayout;

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        switch (requestCode)
        {
            case Common.PERMISSION_REQUEST_CODE:
            {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
                {
                    AlertDialog dialog = new SpotsDialog(ViewWallpaper.this);
                    dialog.show();
                    dialog.setMessage("Please Wait....");

                    String fileName = UUID.randomUUID().toString()+".png";
                    Picasso.with(getBaseContext())
                            .load(Common.select_background.getimageLink())
                            .into(new SaveImageHelper(getBaseContext(),
                                    dialog,
                                    getApplicationContext().getContentResolver(),
                                    fileName,
                                    "WallDeck Wallpapers"));
                }
                else
                    Toast.makeText(this,"You need to grant permission to download image", Toast.LENGTH_SHORT).show();
            }
        }
    }

    private Target target = new Target(){

        @Override
        public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {

        }

        @Override
        public void onBitmapFailed(Drawable errorDrawable) {

        }

        @Override
        public void onPrepareLoad(Drawable placeHolderDrawable) {

        }
    };
    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_view_wallpaper);

        Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        if (getSupportActionBar() != null)
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        //Init
        rootLayout = (CoordinatorLayout)findViewById(R.id.rootLayout);
        collapsingToolbarLayout = (CollapsingToolbarLayout)findViewById(R.id.collapsing);
        collapsingToolbarLayout.setCollapsedTitleTextAppearance(R.style.CollapsedAppBar);
        collapsingToolbarLayout.setExpandedTitleTextAppearance(R.style.ExpandedAppBar);

        collapsingToolbarLayout.setTitle(Common.CATEGORY_SELECTED);

        imageView = (ImageView)findViewById(R.id.imageThumb);
        Picasso.with(this)
                .load(Common.select_background.getimageLink())
                .into(imageView);

        floatingActionButton = (FloatingActionButton)findViewById(R.id.fabWallpaper);
        floatingActionButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Picasso.with(getBaseContext())
                        .load(Common.select_background.getimageLink())
                        .into(target);
            }
        });

        fabDownload = (FloatingActionButton)findViewById(R.id.fabDownload);
        fabDownload.setOnClickListener(new View.OnClickListener() {
            @RequiresApi(api = Build.VERSION_CODES.M)
            @Override
            public void onClick(View view) {
                //Check Permission
                if (ActivityCompat.checkSelfPermission(ViewWallpaper.this,
                        Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)
                {
                    requestPermissions(new String[]{ Manifest.permission.WRITE_EXTERNAL_STORAGE}, Common.PERMISSION_REQUEST_CODE);
                    return;
                }
                else
                {
                    AlertDialog dialog = new SpotsDialog(ViewWallpaper.this);
                    dialog.show();
                    dialog.setMessage("Please Wait....");

                    String fileName = UUID.randomUUID().toString()+".png";
                    Picasso.with(getBaseContext())
                            .load(Common.select_background.getimageLink())
                            .into(new SaveImageHelper(getBaseContext(),
                                    dialog,
                                    getApplicationContext().getContentResolver(),
                                    fileName,
                                    "WallDeck Wallpapers"));
                }
            }
        });

    }

    @Override
    protected void onDestroy() {
        Picasso.with(this).cancelRequest(target);
        super.onDestroy();
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        if (item.getItemId() == android.R.id.home)
            finish();
        return super.onOptionsItemSelected(item);
    }
}

我已经在 HomeActivity 中请求了外部写入权限:

@Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        switch (requestCode)
        {
            case Common.PERMISSION_REQUEST_CODE:
            {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
                    Toast.makeText(this,"Permission Granted", Toast.LENGTH_SHORT).show();
                else
                    Toast.makeText(this,"You need to grant permission to download image", Toast.LENGTH_SHORT).show();
            }
                break;
        }
    }

    private AppBarConfiguration mAppBarConfiguration;
    private Object Context;

    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);
        Toolbar toolbar = findViewById(R.id.toolbar);
        toolbar.setTitle("WallZone Pro");
        setSupportActionBar(toolbar);

        // Request Runtime Permission
        if (ActivityCompat.checkSelfPermission(this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)
        {
             requestPermissions(new String[]{ Manifest.permission.WRITE_EXTERNAL_STORAGE},Common.PERMISSION_REQUEST_CODE);
        }

请帮忙!

Answer 1

请添加要转到ViewWallpaper.class的类