Get a picture from filedialog in android and show it in imageview

Question

I want to take a picture from file chooser and show it on an image view.. but when I run my app it would be stopped and doesn't work. where is problem? this codes are code of 'MainActivity.java'.I didn't change any thing in other files of my project.MY codes are based on this link .My codes are:

public class MainActivity extends Activity {

    private static final int FILE_SELECT_CODE = 0;
    private static final String TAG = null;
    public TextView tv=(TextView) findViewById(R.id.textView1);
    ImageView iv=(ImageView) findViewById(R.id.imageView1);
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button b=(Button) findViewById(R.id.button1);


        b.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                showFileChooser();

            }
        });
    }


    private void showFileChooser() {

        Intent intent = new Intent(Intent.ACTION_GET_CONTENT); 
        intent.setType("*/*"); 
        intent.addCategory(Intent.CATEGORY_OPENABLE);

        try {
            startActivityForResult(
                    Intent.createChooser(intent, "Select a File to Upload"),
                    FILE_SELECT_CODE);
        } catch (android.content.ActivityNotFoundException ex) {
            // Potentially direct the user to the Market with a Dialog
            Toast.makeText(this, "Please install a File Manager.", 
                    Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (requestCode) {
            case FILE_SELECT_CODE:
            if (resultCode == RESULT_OK) {
                // Get the Uri of the selected file 
                Uri uri = data.getData();
                iv.setImageURI(uri);
                Log.d(TAG, "File Uri: " + uri.toString());
               }
            break;
        }
        super.onActivityResult(requestCode, resultCode, data);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

log is:

12-12 04:21:32.343: D/AndroidRuntime(1068): Shutting down VM
12-12 04:21:32.343: W/dalvikvm(1068): threadid=1: thread exiting with uncaught exception (group=0xb4a60b90)
12-12 04:21:32.433: E/AndroidRuntime(1068): FATAL EXCEPTION: main
12-12 04:21:32.433: E/AndroidRuntime(1068): Process: com.example.a55j, PID: 1068
12-12 04:21:32.433: E/AndroidRuntime(1068): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.a55j/com.example.a55j.MainActivity}: java.lang.NullPointerException
12-12 04:21:32.433: E/AndroidRuntime(1068):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2102)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at android.app.ActivityThread.access$700(ActivityThread.java:135)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at android.os.Handler.dispatchMessage(Handler.java:102)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at android.os.Looper.loop(Looper.java:137)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at android.app.ActivityThread.main(ActivityThread.java:4998)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at java.lang.reflect.Method.invokeNative(Native Method)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at java.lang.reflect.Method.invoke(Method.java:515)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at dalvik.system.NativeStart.main(Native Method)
12-12 04:21:32.433: E/AndroidRuntime(1068): Caused by: java.lang.NullPointerException
12-12 04:21:32.433: E/AndroidRuntime(1068):     at android.app.Activity.findViewById(Activity.java:1883)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at com.example.a55j.MainActivity.<init>(MainActivity.java:23)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at java.lang.Class.newInstanceImpl(Native Method)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at java.lang.Class.newInstance(Class.java:1208)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
12-12 04:21:32.433: E/AndroidRuntime(1068):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2093)
12-12 04:21:32.433: E/AndroidRuntime(1068):     ... 11 more
12-12 04:21:34.823: I/Process(1068): Sending signal. PID: 1068 SIG: 9

activiyt_main xml is:

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView1"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="35dp"
        android:layout_toRightOf="@+id/textView1"
        android:text="@string/open" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/button1"
        android:layout_marginTop="81dp"
        android:layout_toLeftOf="@+id/button1"
        android:src="@drawable/ic_launcher" />

</RelativeLayout>

You are setting content view after. but that textview and imageview inside in that content view. — Kanwaljit Singh, Dec 12 '13 at 10:03

Kanwaljit Singh · Accepted Answer · 2013-12-12T09:58:43.557

Try this-

 public class MainActivity extends Activity {

        private static final int FILE_SELECT_CODE = 0;
        private static final String TAG = null;
        public TextView tv;
        public ImageView iv;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            tv=(TextView) findViewById(R.id.textView1);
            iv=(ImageView) findViewById(R.id.imageView1);
            Button b=(Button) findViewById(R.id.button1);


            b.setOnClickListener(new View.OnClickListener() {

                public void onClick(View v) {
                    showFileChooser();

                }
            });
        }


        private void showFileChooser() {

            Intent intent = new Intent(Intent.ACTION_GET_CONTENT); 
            intent.setType("*/*"); 
            intent.addCategory(Intent.CATEGORY_OPENABLE);

            try {
                startActivityForResult(
                        Intent.createChooser(intent, "Select a File to Upload"),
                        FILE_SELECT_CODE);
            } catch (android.content.ActivityNotFoundException ex) {
                // Potentially direct the user to the Market with a Dialog
                Toast.makeText(this, "Please install a File Manager.", 
                        Toast.LENGTH_SHORT).show();
            }
        }

        @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent data) {
            switch (requestCode) {
                case FILE_SELECT_CODE:
                if (resultCode == RESULT_OK) {
                    // Get the Uri of the selected file 
                    Uri uri = data.getData();
                    iv.setImageURI(uri);
                    Log.d(TAG, "File Uri: " + uri.toString());
                   }
                break;
            }
            super.onActivityResult(requestCode, resultCode, data);
        }

        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            // Inflate the menu; this adds items to the action bar if it is present.
            getMenuInflater().inflate(R.menu.main, menu);
            return true;
        }

    }

I do it , but my problem didn't solved. when I run it my app stopped and didn't work — user2855778, Dec 12 '13 at 09:39
OK worked. but when choose a picture from file explorer imageview didn't show any thing — user2855778, Dec 12 '13 at 10:06
see this link https://github.com/iPaulPro/aFileChooser/blob/master/aFileChooserExample/src/com/ipaulpro/afilechooserexample/FileChooserExampleActivity.java — Kanwaljit Singh, Dec 12 '13 at 10:18

Techfist · Answer 2 · 2013-12-12T09:54:34.200

0

See this at android.app.Activity.findViewById(Activity.java:1883), it means your XML file R.layout.activity_main does not have a button with name button1, check that.

public TextView tv=(TextView) findViewById(R.id.textView1);
ImageView iv=(ImageView) findViewById(R.id.imageView1);

Put it inside OnCreate after setting content view, you are trying to access them even before your layout is actually inflated, thats y this error is coming.

edited Dec 12 '13 at 09:54

answered Dec 12 '13 at 09:37

Techfist

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I put `button1` myself in `activity_main.xml` and checked it. I view this button on it!!!! – user2855778 Dec 12 '13 at 09:43
I added xml file to my answer – user2855778 Dec 12 '13 at 09:48
Modifeid my answer, change your code as suggested and you will get your answer – Techfist Dec 12 '13 at 09:54
thanks alot... solved. but when I choose a picture , imageview didn't show any thing! – user2855778 Dec 12 '13 at 10:03

score 0 · Answer 3 · answered Dec 12 '13 at 10:08

Try this. It's working on my machine.

public class MainActivity extends Activity {

private static final int FILE_SELECT_CODE = 0;

// private static final String TAG = null;

TextView tv;
ImageView iv;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button b=(Button) findViewById(R.id.button1);
    tv=(TextView) findViewById(R.id.textView1);
    iv=(ImageView) findViewById(R.id.imageView1);



    b.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            showFileChooser();

        }
    });
}


private void showFileChooser() {

    Intent intent = new Intent(Intent.ACTION_GET_CONTENT); 
    intent.setType("*/*"); 
    intent.addCategory(Intent.CATEGORY_OPENABLE);

    try {
        startActivityForResult(
                Intent.createChooser(intent, "Select a File to Upload"),
                FILE_SELECT_CODE);
    } catch (android.content.ActivityNotFoundException ex) {
        // Potentially direct the user to the Market with a Dialog
        Toast.makeText(this, "Please install a File Manager.", 
                Toast.LENGTH_SHORT).show();
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch (requestCode) {
        case FILE_SELECT_CODE:
        if (resultCode == RESULT_OK) {
            // Get the Uri of the selected file 
            Uri uri = data.getData();
            iv.setImageURI(uri);
       //     Log.d(TAG, "File Uri: " + uri.toString());
           }
        break;
    }
    super.onActivityResult(requestCode, resultCode, data);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

score 0 · Answer 4 · answered Dec 12 '13 at 10:10

According to your LogCat error you are getting NullPointerException

Initilize your ImageView and TextView globally (before OnCreate) like

ImageView iv;
TextView tv;

and put findViewById(R.id.imageView1) and findViewById(R.id.textView1) within onCreate method.

Get a picture from filedialog in android and show it in imageview

4 Answers4