Question

我确定某处有答案，但我似乎无法找到任何答案。我试图这样做，当用户点击应用程序菜单上的某个项目时，它会启动一个意图到手机的图库，以选择他们选择的图像来更改应用程序的背景而不是预先设置背景图像。有没有办法做到这一点。

这是我的代码，但是当我在手机上运行时，应用程序崩溃了。

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    Intent sendIntent = null;
    if (id == R.id.action_settings) {


        sendIntent = new Intent();
        sendIntent.setAction(Intent.ACTION_SEND);
        sendIntent.putExtra(Intent.EXTRA_TEXT, "Try Out this new app...");
        sendIntent.setType("text/plain");
        startActivity(sendIntent);
    }


    PackageManager packageManager = getPackageManager();
    List<ResolveInfo> activities =                   packageManager.queryIntentActivities(sendIntent, 0);
    boolean isIntentSafe = activities.size() > 0;


    String title = getResources().getString(R.string.chooser_title);

    Intent chooser = Intent.createChooser(sendIntent, title);


    if (sendIntent.resolveActivity(getPackageManager()) != null) {
        startActivity(chooser);
    }



    //noinspection SimplifiableIfStatement

    if (id == R.id.change_background){
    Intent pictureIntent = new Intent();
    pictureIntent.setType("image/*");
    pictureIntent.setAction(Intent.ACTION_GET_CONTENT);
    startActivityForResult(Intent.createChooser(pictureIntent,

＆＃34;选择图片＆＃34;），0）;

}

    return true;

}}

Answer 1

从图库中选择图像

try {
                Intent intent = new Intent();
                intent.setType("image/*");
                intent.setAction(Intent.ACTION_GET_CONTENT);
                startActivityForResult(Intent.createChooser(intent, "Select Picture"),  PICK_IMAGE);
            } catch (Exception e) {
                Toast.makeText(getApplicationContext(),e.getMessage(),Toast.LENGTH_LONG).show();
                Log.e(e.getClass().getName(), e.getMessage(), e);
            }

和OnActivityResult

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    switch (requestCode) {
    case PICK_IMAGE:

        if (resultCode == Activity.RESULT_OK) {
            Uri selectedImageUri = data.getData();
            try {
                // OI FILE Manager
                String filemanagerstring = selectedImageUri.getPath();

                // MEDIA GALLERY
                String selectedImagePath = getPath(selectedImageUri);

                if (selectedImagePath != null) {
                    filePath = selectedImagePath;
                } else if (filemanagerstring != null) {
                    filePath = filemanagerstring;
                } else {
                    Toast.makeText(getApplicationContext(), "Unknown path",
                            Toast.LENGTH_LONG).show();

                }

                if (filePath != null) {         

                    decodeFile(filePath);
                } else {
                    bitmap = null;
                }
            } catch (Exception e) {
                Toast.makeText(getApplicationContext(), "Internal  
                     error",Toast.LENGTH_LONG).show();

            }
        }
        break;
    default:
    }



}


     //Decode file() where you will get decoded file and then you can use that image
      //file according to your requirement

   public void decodeFile(String filePath) {

    // Decode image size
    BitmapFactory.Options o = new BitmapFactory.Options();
    o.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(filePath, o);

    // The new size we want to scale to
    final int REQUIRED_SIZE = 1024;

    // Find the correct scale value. It should be the power of 2.
    int width_tmp = o.outWidth, height_tmp = o.outHeight;
    int scale = 1;
    while (true) {
        if (width_tmp < REQUIRED_SIZE && height_tmp < REQUIRED_SIZE)
            break;
        width_tmp /= 2;
        height_tmp /= 2;
        scale *= 2;  
    }

    // Decode with inSampleSize
    BitmapFactory.Options o2 = new BitmapFactory.Options();
    o2.inSampleSize = scale;
    bitmap = BitmapFactory.decodeFile(filePath, o2);

    image.setImageBitmap(bitmap);// set ImageView in your case set Layout  
              //background

}

Answer 2

试试这个。这不是最好的方法。但它满足了你的需求。

xml文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/rl"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<ImageView
    android:id="@+id/img"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:scaleType="fitXY" />

<Button
    android:id="@+id/butt"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    android:text="Click Me" />

Java文件

public class MainActivity extends ActionBarActivity {

private static int RESULT_LOAD_IMG = 1;
String path = "";

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

    Button btn = (Button) findViewById(R.id.butt);
    btn.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            Intent i = new Intent(
                    Intent.ACTION_PICK,
                    android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(Intent.createChooser(i, "Select Icon"),
                    RESULT_LOAD_IMG);
        }
    });
}

public String getPath(Uri uri) {
    String[] projection = { MediaStore.Images.Media.DATA };
    Cursor cursor = managedQuery(uri, projection, null, null, null);

    int column_index = cursor
            .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
    cursor.moveToFirst();
    return cursor.getString(column_index);
}

@Override
protected void onActivityResult(int arg0, int arg1, Intent arg2) {
    super.onActivityResult(arg0, arg1, arg2);
    try {

        if (arg0 == RESULT_LOAD_IMG && arg1 == RESULT_OK && null != arg2) {
            Uri selectedImage = arg2.getData();
            path = getPath(selectedImage);

            ImageView iv = (ImageView) findViewById(R.id.img);
            iv.setImageURI(selectedImage);

        } else {
            Toast.makeText(getApplicationContext(),
                    "You haven't picked Image", Toast.LENGTH_LONG).show();
        }

    } catch (Exception e) {
        Toast.makeText(getApplicationContext(), "Something went wrong",
                Toast.LENGTH_LONG).show();
    }
}

如何从电话库设置应用背景

2 个答案: