Question

出于某种原因，当我在按钮监听器中调用startActivityForResult并从活动返回时，所有按钮此后都停止工作。它通过并退出onActivityResult就好了，应用程序没有冻结，因为我仍然可以点击按钮，尽管他们什么都不做。启动应用程序时它可以正常工作。我在这里缺少什么？

public class MainActivity extends Activity {

    static final int CAMERA_RESULT_CODE = 1;
    static final int INFO_RESULT_CODE = 2;
    static final int SYMPTOM_RESULT_CODE = 3;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

        // Set the user interface elements
        final Button btnCameraActivity = (Button) findViewById(R.id.btnCameraActivity);
        btnCameraActivity.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, CropActivity.class);
                startActivityForResult(intent, CAMERA_RESULT_CODE);
            }
        });

        final Button btnAgeActivity = (Button) findViewById(R.id.btnAgeActivity);
        btnAgeActivity.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, AgeActivity.class);
                startActivityForResult(intent, INFO_RESULT_CODE);
            }
        });

        final Button btnSymptomActivity = (Button) findViewById(R.id.btnSymptomActivity);
        btnSymptomActivity.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, SymptomActivity.class);
                startActivityForResult(intent, SYMPTOM_RESULT_CODE);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        setContentView(R.layout.activity_main);
        switch (requestCode) {
            case CAMERA_RESULT_CODE:
                if (resultCode == RESULT_OK) {
                    final CheckBox cb1 = (CheckBox) findViewById(R.id.cbCameraActivity);
                    cb1.setChecked(true);
                }
                break;
            case INFO_RESULT_CODE:
                if (resultCode == RESULT_OK) {
                    final CheckBox cb2 = (CheckBox) findViewById(R.id.cbAgeActivity);
                    cb2.setChecked(true);
                }
                break;
            case SYMPTOM_RESULT_CODE:
                if (resultCode == RESULT_OK) {
                    final CheckBox cb3 = (CheckBox) findViewById(R.id.cbSymptomActivity);
                    cb3.setChecked(true);
                }
                break;
        }
    }
}

Answer 1

setContentView()中的onActivityResult()来电正在替换您在onCreate()中设置的布局，因此您设置Button的{{1}}个实例已经不见了。

只需从OnClickListener的顶部删除该来电。

Answer 2

将此代码放在onResume方法

中

    final Button btnCameraActivity = (Button) findViewById(R.id.btnCameraActivity);
    btnCameraActivity.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this, CropActivity.class);
            startActivityForResult(intent, CAMERA_RESULT_CODE);
        }
    });

    final Button btnAgeActivity = (Button) findViewById(R.id.btnAgeActivity);
    btnAgeActivity.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this, AgeActivity.class);
            startActivityForResult(intent, INFO_RESULT_CODE);
        }
    });

    final Button btnSymptomActivity = (Button) findViewById(R.id.btnSymptomActivity);
    btnSymptomActivity.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this, SymptomActivity.class);
            startActivityForResult(intent, SYMPTOM_RESULT_CODE);
        }
    });

此类代码通常可以通过将您的课程扩展到View.OnClickListener

来简化

从另一个活动

2 个答案: