java - 无法启动新活动

Question

美好的一天，我尝试从另一个开始新的活动。但它总是崩溃。这里我的代码。它是 ListView 上的事件。

list.setOnItemClickListener(new OnItemClickListener(){
            public void onItemClick(AdapterView<?> parent, View view, int position, long id){
                Student selected = (Student)list.getItemAtPosition(position);
                String selectedTitle = selected.FirstName;  //ideally this would probably be done with accessors
                int selectedId = selected.studentId;
                String selectedDescription = selected.LastName;

               Intent i = new Intent(view.getContext(), StudentInfoActivity.class);
               i.putExtra("studentId", selectedId);
               try{
                   startActivity(i);
               }catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

            }
        });

A 向 Manifest 添加了一个活动

<activity
            android:name=".StudentInfoActivity"
            android:label="@string/app_name" >
        </activity>

错误消息是

06-15 17:17:00.471: E/AndroidRuntime(602): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.marat.mutw/com.marat.mutw.StudentInfoActivity}: java.lang.NullPointerException: uriString

所有以前的活动，我添加的那些都很好......

学生信息活动

public class StudentInfoActivity extends Activity {

    ImageView image;
    TextView firstLastName;
    TextView studentInfo;
    TextView addInfo;
    Student std;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.sudentinfolayout);

        image = (ImageView)findViewById(R.id.avatar);
        firstLastName = (TextView)findViewById(R.id.firstNameLastName);
        studentInfo = (TextView)findViewById(R.id.studentinfo);
        addInfo = (TextView)findViewById(R.id.description);

        int studentId = getIntent().getExtras().getInt("studentId");
        JSONHandler handler = new JSONHandler(this.getApplicationContext());
        std = new Student();
        std = handler.GetStudentInfo(studentId);
        image.setImageURI(Uri.parse(std.imagePath));
        firstLastName.setText(std.FirstName+ "  "+std.LastName);




    }
    public void onClickApply(View view){

    }

}

Answer 1

代替

Intent i = new Intent(view.getContext(), StudentInfoActivity.class);

改成

Create static object of that activity 

例如 Activity actOne =null;

public static actOne a ;
a = this;

Intent i = new Intent(a, StudentInfoActivity.class);

Answer 2

试试这个。

Intent i = new Intent(getApplicationContext(), StudentInfoActivity.class);
i.putExtra("studentId", selectedId);
startActivity(i);