图像点按钮中的问题

Question

我尝试了许多解决方法，其中很少有人在评论中提到。没有什么可用。该应用程序仅在调用startActivityForresult（）方法时就会崩溃。

这是我所有的源代码：

---

XML

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.shubhamr69.app"
    android:versionCode="1"
    android:versionName="1.0">
    
    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="25" />
    
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme">

        <activity android:name="com.shubhamr69.app.MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
    
    <uses-permission
        android:name="android.permission.READ_EXTERNAL_STORAGE"
    />
    <uses-permission
        android:name="android.permission.WRITE_EXTERNAL_STORAGE"
    />

</manifest>

---

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_centerHorizontal="true"
    android:orientation="vertical"
    tools:context=".MainActivity"
    >
    
    <TextView
      android:id="@+id/Label1"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:text="Progress..."
    ></TextView>

    <Button
      android:id="@+id/ImagePicker1"
      android:layout_below="@id/Label1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="32dp"
      android:text="SELECT IMAGE"
      android:textColor="@android:color/black"
      android:textSize="18sp"
    ></Button>
    
    <ImageView
      android:id="@+id/Image1"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_below="@id/ImagePicker1"
      android:layout_marginTop="16dp"
    ></ImageView>
    
</LinearLayout>

---

strings.xml

<resources>
    <string name="app_name">MyApp</string>
    <!-- This String is provided by default. -->
    <string name="title_activity_main">MAIN_ACTIVITY</string>
</resources>

---

styles.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="@android:style/Theme.Light" />

</resources>

---

Java

MainActivity.java

package com.shubhamr69.app;

import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import com.shubhamr69.Components.ImagePicker;
import com.shubhamr69.app.R;

public class MainActivity extends Activity {

  ImagePicker imagePicker1;
  public static ImageView image1;
  public static TextView label1;
  
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setup();
    }
    
    public void setup(){
      imagePicker1 = new ImagePicker();
      label1 = findViewById(R.id.Label1);
      image1 = findViewById(R.id.Image1);
      Button iPB1 = (Button)(findViewById(R.id.ImagePicker1));
      // initializing the ImagePicker.
      imagePicker1.initialize(iPB1);
      imagePicker1.setOnImagePicked(new Runnable(){
        @Override
        public void run() {
          MainActivity.image1.setImageURI(imagePicker1.getContentUri());
          MainActivity.label1.setText("Runnable Complete.");
        }
      });
      
    }
    
  
}

***

---

ImagePicker.java

package com.shubhamr69.app.Components;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import com.shubhamr69.app.MainActivity;

public class ImagePicker extends Activity {
  
  private Button imagePicker;
  private Uri contentUri = null;
  private String imagePath = "";
  public boolean gotImage = false;
  public Runnable runnable = new Runnable(){
    @Override
    public void run(){}
  };
  
  public ImagePicker(){
    
  }
  
  // Initializing ImagePicker for a Button.
  public void initialize(Button button){
    imagePicker = button;
    imagePicker.setOnClickListener(new View.OnClickListener(){
      @Override
      public void onClick(View view) {
        MainActivity.label1.setText("Button Clicked.");
        // I tried using this both in and out of a new Thread(). Nothing works.
        new Thread(){
          @Override
          public void run(){
            chooseImage();
          }
        }.start();
      }
    });
    
  }
  
  public void chooseImage(){
    MainActivity.label1.setText("chooseImage() Called.");
    Intent picker = new Intent();
    picker.setType("image/*");
    picker.setAction(Intent.ACTION_PICK);
    MainActivity.label1.setText("Intent Set and about to be executed.");
    // Problem starts here. Everything before this works.
    // The ImagePicker doesn't even open and the App crashes.
    startActivityForResult(picker, 200); 
  }
  
  @Override
  public void onActivityResult(int requestCode, int resultCode, Intent data){
    super.onActivityResult(requestCode, resultCode, data);
    MainActivity.label1.setText("Got Intent Result"); 
    contentUri = (resultCode == RESULT_OK && requestCode==200)?data.getData():null;
    imagePath = (contentUri != null) ? contentUri.getPath() : "";
    gotImage = true;
    MainActivity.label1.setText("Starting Run Runnable.");
    super.runOnUiThread(runnable);
  }
  
  public void setOnImagePicked(Runnable runnableObject){
    runnable = runnableObject;
  }
  
  public Uri getContentUri(){
    return contentUri;
  }
  
  public String getPath(){
    return imagePath;
  }
  
  
}

---

textView label1 仅用于检查应用程序的工作量。

当我第一次使用imagepicker.java mainActivity.java中的代码时，一切正常。但是，当我想将ImagePicker的代码放在单独的类中时，我制作了imagepicker.java文件，然后将所有内容移动到那里。

如果您在我的代码中找不到错误，则至少给我一个工作src，用于imagepicker.java class。

Answer 1

我认为您有ActivityNotFoundException，因为您没有在清单中提到您的ImagePicker活动。
因此，您必须将 imagePicker`添加到清单中，并且您表现出来应该是

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.shubhamr69.app"
    android:versionCode="1"
    android:versionName="1.0">
    
    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="25" />
    
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme">

        <activity android:name="com.shubhamr69.app.MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
  <activity android:name="com.shubhamr69.app.ImagePicker"/>
           

    </application>
    
    <uses-permission
        android:name="android.permission.READ_EXTERNAL_STORAGE"
    />
    <uses-permission
        android:name="android.permission.WRITE_EXTERNAL_STORAGE"
    />

</manifest>