这个例子是《第一行代码》8.3.1的例子。下面我把代码粘贴下。
Mainactivity:
public class MainActivity extends AppCompatActivity {
public static final int TAKE_PHOTO = 1;
private ImageView picture;
private Uri imageUri;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
picture = findViewById(R.id.picture);
setContentView(R.layout.activity_main);
Button takePhoto = findViewById(R.id.take_photo);
takePhoto.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
File outputImage = new File(getExternalCacheDir(), "pic.jpg");
try {
if (outputImage.exists()) {
outputImage.delete();
}
outputImage.createNewFile();
}catch (IOException e) {
e.printStackTrace();
}
if (Build.VERSION.SDK_INT >= 24) {
imageUri = FileProvider.getUriForFile(MainActivity.this, "com.wang.zhihai" +
".cameratest" +
".fileprovider", outputImage);
}else {
imageUri = Uri.fromFile(outputImage);
}
//启动相机
Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
startActivityForResult(intent, TAKE_PHOTO);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode) {
case TAKE_PHOTO:
if (resultCode == RESULT_OK) {
try {
Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver()
.openInputStream(imageUri));
picture.setImageBitmap(bitmap);
}catch (FileNotFoundException e) {
e.printStackTrace();
}
}
break;
default:
break;
}
}
}
Menifest 文件:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.wang.zhihai.cameratest">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<!--<uses-permission android:name="android.permission.CAMERA"/>-->
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<provider
android:authorities="com.wang.zhihai.cameratest.fileprovider"
android:exported="false"
android:name="android.support.v4.content.FileProvider"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths"/>
</provider>
</application>
</manifest>
file_paths文件:
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path
name="my_images"
path=""/>
</paths>
我的手机是华为Mate 10, Android 8.0 ,运行后拍照,储存拍摄的照片到布局文件的ImageView控件中。点击完成拍摄APP就闪退了。log显示NullPointerException。
报错的代码在onActivityResult 方法的 picture.setImageBitmap(bitmap);
求大神帮忙!