如何使 "ImageView" 字段在 android 中成为必填项？

Question

我的 android 应用程序中有一个 imageview 字段，单击它我提供了 "open camera" 功能，用户可以单击相机中的照片并将其上传到 ImageView

  b1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            if(user_image.getDrawable() == null ){

                Toast.makeText(NewCall4.this, "No image uploaded", Toast.LENGTH_SHORT).show();
            }
            else{

                Intent i=new Intent(NewCall4.this,NewCall5.class);
                startActivity(i);
            }

        }
    }
    );

我想要的是，如果我没有在图像视图中上传图像，那么它应该将 error/toast 消息显示为 "Image not uploaded"

Answer 1

您好，您可以尝试这样的操作

 Imageview img = (ImageView)findViewById(R.id.image){

    img .setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    startActivityForResult(intent, id);
                }
    });

和 OnResult

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

Bitmap photo = (Bitmap) data.getExtras().get(“data”);
img.setImageBitmap(photo);
 }

Answer 2

就是这么简单。当您调用 Intent for camera open 时，它会在 onActivityResult 中提供回调，因为它只传递图像的值。并在点击事件中检查是否为null。

Example :-

=> 打开相机 :-

Intent intent1 = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent1, camera);

您将在 onActivityResult 中获得回调

=> onActivityResult :-（我在这里获取实际的图像路径）

if (resultCode == RESULT_OK && requestCode == camera) {
    Bitmap photo = (Bitmap) data.getExtras().get("data");
    addprofile.setImageBitmap(photo); // set image to imageview
    Uri tempUri = getImageUri(getApplicationContext(), photo);
    File finalfile = new File(getrealpathfromuri(tempUri));
    imagepath = finalfile.toString(); // imagepath is a global variable
}

private Uri getImageUri(Context applicationContext, Bitmap photo) {
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    photo.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
    String path = MediaStore.Images.Media.insertImage(applicationContext.getContentResolver(),photo,"Title",null);
    return Uri.parse(path);
}

private String getrealpathfromuri(Uri tempUri) {
    String path = "";
    if(getContentResolver() != null){
        Cursor cursor = getContentResolver().query(tempUri, null, null, null, null);
        if(cursor != null){
            cursor.moveToFirst();
            int idk = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
            path = cursor.getString(idk);
            cursor.close();
        }
    }
    return path;
}

终于imagepath有了图片的实际路径。

=> 检查图像路径是否为 null :-（在事件中）

if (imagepath == null) {
   Toast.makeText(this, "Please Select FileImage", Toast.LENGTH_SHORT).show();
}

Answer 3

如果附加到 ImageView，您可以检查 Drawable

Imageview imageView = (ImageView)findViewById(R.id.image);
if(imageView.getDrawable() == null){
 //Then Nothing is attached with imageviw
}

如何使 "ImageView" 字段在 android 中成为必填项？

How to make a "ImageView" field as mandatory in android?

android

image

android-imageview