Android-使用相机拍照

Question

I am new to android, and I am trying to make my app take a picture from the camera. Looking at the example provided here , I tried to implement in my app in MainActivity.java as such:

public class MainActivity extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main); // line 17
}


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

@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
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

static final int REQUEST_IMAGE_CAPTURE = 1;

public void dispatchTakePictureIntent(View view) {
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
}
}

Here is my activity_main.xml :

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

    <TextView android:text="@string/welcome" android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:layout_centerHorizontal="true"
        android:textSize="40dp" android:textStyle="bold" android:textColor="#990000"/>
    <GridView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:numColumns="2"
        android:columnWidth="50dp"
        android:gravity="center_horizontal">
            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/picture_1"
                android:onClick="dispatchTakePictureIntent"/>
        </GridView>

</RelativeLayout>

I am getting the following error:

java.lang.RuntimeException: Unable to start activity ComponentInfo{---/.MainActivity}: java.lang.UnsupportedOperationException: addView(View, LayoutParams) is not supported in AdapterView
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2209)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2269)
        at android.app.ActivityThread.access$800(ActivityThread.java:139)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5102)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
        at dalvik.system.NativeStart.main(Native Method)
        Caused by: java.lang.UnsupportedOperationException: addView(View, LayoutParams) is not supported in AdapterView
        at android.widget.AdapterView.addView(AdapterView.java:478)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:759)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:758)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
          at android.support.v7.app.ActionBarActivityDelegateBase.setContentView(ActionBarActivityDelegaeBase.java:228)
        at android.support.v7.app.ActionBarActivity.setContentView(ActionBarActivity.java:102)
        at ---/.MainActivity.onCreate(MainActivity.java:17)
        at android.app.Activity.performCreate(Activity.java:5248)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1110)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2173)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2269)
            at android.app.ActivityThread.access$800(ActivityThread.java:139)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5102)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
            at dalvik.system.NativeStart.main(Native Method)

I am probably doing something wrong, so can anyone point out my mistake? Thanks in advance.

Answer 1

UnsupportedOperationException: addView(View, LayoutParams) is not supported in AdapterView

A subclass of AdapterView (in your case GRIDVIEW) can't have children manually added either in the layout file or added in code.

Your code:

 <GridView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:numColumns="2"
        android:columnWidth="50dp"
        android:gravity="center_horizontal">
            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/picture_1"
                android:onClick="dispatchTakePictureIntent"/>
        </GridView>

Don't do it !

As this will call the addView method of GridView, throwing the exception. Instead use:

      <GridView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:numColumns="2"
            android:columnWidth="50dp"
            android:gravity="center_horizontal"/>

Also, if you use the LayoutInflater.inflate method in the code of the Activity or the adapter(its getView method), don't pass the GridView as the second parameter. For example, don't use:

convertView  = inflator.inflate(R.layout.child, parent);

Instead use:

convertView  = inflator.inflate(R.layout.child, parent, false);

Answer 2

Why you are adding Button in GridView in yout xml ?

GridView is not designed for this purpose. Put the button outside the GridView and try. Error is about that.

GridView can only be used to display views in Grid Pattern and it uses Adapter to display data.

Answer 3

Use your grid View like this:

 <GridView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:numColumns="2"
            android:columnWidth="50dp"
            android:gravity="center_horizontal"/>

GridView is used to display views in Grid Pattern and similarly uses Adapter to display data.