Android programmatically add ImageView

Question

I just started learning Android programming. I created a new project (API 19) with a blank activity and tried to add an ImageView like this: (in the MainActivity's onCreate() ) ``` setContentView(R.layout.activity_main); View view = (View) findViewById(R.layout.activity_main); LinearLayout picLL = new LinearLayout(MainActivity.this); picLL.layout(0, 0, 100, 100); picLL.setLayoutParams(new LayoutParams(100, 100)); picLL.setOrientation(LinearLayout.HORIZONTAL); ((ViewGroup) view).addView(picLL); // <- This is line 36 ImageView myImage = new ImageView(this); myImage.setImageResource(R.drawable.ic_launcher); picLL.addView(myImage); ``` However the app crashes immediately after launch. I've tried numerous other answers from Stackoverflow, but none worked. There seems to be something I am missing... This is the LogCat output: ``` 04-17 10:02:35.611: E/AndroidRuntime(1402): FATAL EXCEPTION: main 04-17 10:02:35.611: E/AndroidRuntime(1402): Process: com.example.test, PID: 1402 04-17 10:02:35.6…

Accepted Answer

It happens because you are trying to find `View` by layout's id.

```
View view = (View) findViewById(R.layout.activity_main); 
```

You have two options: You can add any id for root element in `activity_main.xml`. For example it will be `root_layout_id`. Then you can find it like:

```
View view = (View) findViewById(R.id.root_layout_id); 
```

The second option is to create layout programatically at all. Change your onCreate() method like this:

```
@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        LinearLayout picLL = new LinearLayout(this);
        picLL.layout(0, 0, 100, 100);
        picLL.setLayoutParams(new LayoutParams(100, 100));
        picLL.setOrientation(LinearLayout.HORIZONTAL);
        ImageView myImage = new ImageView(this);
        myImage.setImageResource(R.drawable.ic_launcher);
        picLL.addView(myImage);
        setContentView(picLL);
    }
```

Android programmatically add ImageView

Solution

Problem