Question

package com.example.hussain.assignment4task1;

import android.os.Parcel;
import android.os.Parcelable;

import java.lang.reflect.Array;
import java.util.ArrayList;

public class Image implements Parcelable
{
    private String imageName;
    private String date;
    public ArrayList<Image> images;


public Image(String imageName, String date, ArrayList<Image> images)
{
    update(imageName, date, images);
}

public void update(String imageName, String date, ArrayList<Image> images)
{
    this.imageName = imageName;
    this.date = date;
    this.images = images;
}

public String toString()
{
    String str = "Image Name: "+ imageName;
    str += "\nDate: " + date;
    return str;
}

/** The following block of code parcels / unparcels data for distribution between activities */

/** Describe the contents in the parcel --
 * interface forces implementation */
public int describeContents()
{
    return 0;
}

public void writeToParcel(Parcel out, int flags)
{
    out.writeString(imageName);
    out.writeString(date);
    out.writeList(images);
}

public static final Parcelable.Creator<Image> CREATOR =
        new Parcelable.Creator<Image>()
        {
            public Image createFromParcel(Parcel in)
            {
                return new Image(in);
            }

            public Image[] newArray(int size)
            {
                return new Image[size];
            }
        };
/** Private constructor called internally only */
private Image(Parcel in)
{
    imageName = in.readString();
    date = in.readString();
}
}

这是我的活动，我在其中插入要传递给其他活动中的图像的图像细节。

public void onBackPressed()
{
    Log.i("IMAGE DETAILS", "Back Button Pressed");
    storeImageDetails(); // to cover half filled forms
    Intent resultIntent = new Intent(this, MainActivity.class);
    // need an array list even if we put a single object only
    ArrayList<Image> dataList = new ArrayList<Image>(4);
    dataList.add(image);
    resultIntent.putParcelableArrayListExtra("IMAGE_DATA", dataList);
    setResult(RESULT_OK, resultIntent);
    ImageDetailsActivity.super.onBackPressed();  // do not forget
}

/** This method will store all information entered */ 
private void storeImageDetails()
{
    EditText imageNameText = (EditText) findViewById(R.id.imageNameText);
    EditText dateText = (EditText) findViewById(R.id.dateText);
    String imageName = imageNameText.getText().toString();
    String date = dateText.getText().toString();

    ArrayList<Image> dataList = new ArrayList<Image>();

    if (image == null)
        image = new Image(imageName, date, dataList);
    else
        image.update(imageName, date, dataList);

    Log.i("IMAGE DETAILS CHANGED", image.toString());
}

我的主要活动有4张图片。点击其中一个打开一个表格，您可以在其中输入他们的详细信息，按下后退按钮，他们只在图像下方播放图像名称和日期。但这对所有图像都显示相同。我想知道如何制作它，以便只有我点击的图像才能获得传递给它的细节，而不是其他图像。因此，将数据传递给单个图像的分离是我想要的。

Answer 1

我认为public ArrayList<Image> images字段不应该是Image类的一部分，而应该是主要活动中的字段。

尝试这样的事情：

public class MainActivity extends Activity {
    public ArrayList<Image> images;

    // show images list via adapter or something, and put an OnClickListener on each

    private void onImageClicked(int index) {
        Image image = images.get(index);
        Intent intent = new Intent(this, ImageDetailsActivity.class);
        intent.putExtra("IMAGE", image);
        intent.putExtra("INDEX", index);
        startActivityForResult(intent, 12345);
    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == 12345 && resultCode == RESULT_OK) {
            int index = data.getIntExtra("INDEX", -1);
            String name = data.getStringExtra("NAME");
            String date = data.getStringExtra("DATE");

            Image image = images.get(index);
            image.update(name, date);
        }
    }
}

public class ImageDetailsActivity extends Activity {

    public void onBackPressed() {
        EditText imageNameText = (EditText) findViewById(R.id.imageNameText);
        EditText dateText = (EditText) findViewById(R.id.dateText);
        String imageName = imageNameText.getText().toString();
        String date = dateText.getText().toString();

        Intent resultIntent = new Intent(this, MainActivity.class);
        resultIntent.putExtra("INDEX", getIntent().getIntExtra("INDEX", -1)); // return the same index we got from Main
        resultIntent.putExtra("NAME", imageName);
        resultIntent.putExtra("DATE", date);
        setResult(RESULT_OK, resultIntent);

        super.onBackPressed();
    }
}

Android工作室。将数据分配给数组列表中的特定对象

1 个答案: