我创建了一个名为commentasync的新类。我在doInBackground部分中放置了一个findViewById（），它给了我一个错误。这基本上就是我的代码。 findViewById不起作用，它不会让我验证新的视图。 textView或按钮也会出现错误。
public class commentAsync extends AsyncTask<String, String, String> {
UserFunctions userFunctions;
// JSON Response node name
private static String KEY_SUCCESS = "success";
private static String KEY_ERROR_MSG = "error_msg";
private static String KEY_STATE = "state";
private static String KEY_USERNAME = "username";
private static String KEY_COMMENT = "comment";
private static String KEY_COMMENT_ID = "commentID";
private static String KEY_NUMBER_OF_COMMENTS = "numberOfComments";
private static String KEY_POSTED_AT = "posted_at";
private static String KEY_VERIFY = "verify";
private static String KEY_OFFSET_NUMBER = "offsetNumber";
DatabaseHandler db = new DatabaseHandler(getApplicationContext());
String usernameforcomments = db.getUserDetails();
registerErrorMsg = (TextView) findViewById(R.id.collectComment_error);
int verify = 1;
int verify2 = 1;
String offsetNumber = "null";
LinearLayout linear = (LinearLayout) this.findViewById(R.id.commentSection);
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected void onProgressUpdate(String... values) {
super.onProgressUpdate(values);
}
@Override
protected String doInBackground(String... params) {
return null;
UserFunctions CollectComments = new UserFunctions();
JSONObject json = CollectComments.collectComments(usernameforcomments, offsetNumber);
int commentCycle = 1;
// check for comments
try {
if (json.getString(KEY_SUCCESS) != null) {
registerErrorMsg.setText("");
String res2 = json.getString(KEY_SUCCESS);
if(Integer.parseInt(res2) == 1){
String numberOfComments = json.getString(KEY_NUMBER_OF_COMMENTS);
String offsetNumberDb = db.getOffsetNumber();
int numberOfComments2 = Integer.parseInt(numberOfComments) - Integer.parseInt(offsetNumberDb);
offsetNumber = offsetNumberDb;
//if comment number is less than 15 or equal to 15
if(numberOfComments2 <= 15){
while (commentCycle <= numberOfComments2){
JSONObject json2 = CollectComments.collectComments(usernameforcomments, offsetNumber);
LinearLayout commentBox = new LinearLayout(this);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
commentBox.setBackgroundResource(R.drawable.comment_box_bg);
layoutParams.setMargins(0, 10, 0, 10);
commentBox.setPadding(0,0,0,10);
commentBox.setOrientation(LinearLayout.VERTICAL);
linear.addView(commentBox, layoutParams);
RelativeLayout commentBoxHeader = new RelativeLayout(this);
commentBoxHeader.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
commentBoxHeader.setBackgroundResource(R.drawable.comment_box_bg);
commentBoxHeader.setBackgroundResource(R.drawable.comment_box_header);
commentBox.addView(commentBoxHeader);
TextView plateView = new TextView(this);
plateView.setText(json2.getString(KEY_PLATENUMBER));
RelativeLayout.LayoutParams plateViewParam = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
plateViewParam.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
plateView.setTextColor(getResources().getColor(R.color.white));
plateView.setTextSize(15);
plateView.setPadding(10, 5, 5, 5);
plateView.setTypeface(Typeface.DEFAULT_BOLD);
commentBoxHeader.addView(plateView, plateViewParam);
TextView usernameView = new TextView(this);
usernameView.setText("Posted by: " + json2.getString(KEY_USERNAME));
RelativeLayout.LayoutParams usernameViewParam = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
usernameViewParam.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
usernameView.setTextColor(getResources().getColor(R.color.white));
usernameView.setPadding(5, 5, 10, 5);
usernameView.setTypeface(Typeface.DEFAULT_BOLD);
commentBoxHeader.addView(usernameView, usernameViewParam);
TextView commentView = new TextView(this);
commentView.setText(json2.getString(KEY_COMMENT));
LinearLayout.LayoutParams commentViewParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
commentViewParams.setMargins(20, 10, 20, 20);
commentView.setBackgroundResource(R.drawable.comment_bg);
commentView.setTextColor(getResources().getColor(R.color.black));
commentBox.addView(commentView, commentViewParams);
TextView descriptionView = new TextView(this);
descriptionView.setText(json2.getString(KEY_COMMENT));
descriptionView.setPadding(20, 10, 20, 20);
descriptionView.setLayoutParams(new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
descriptionView.setTextColor(getResources().getColor(R.color.black));
commentBox.addView(descriptionView);
RelativeLayout commentBoxButtons = new RelativeLayout(this);
RelativeLayout.LayoutParams commentBoxButtonsParam = new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
commentBox.addView(commentBoxButtons, commentBoxButtonsParam);
Button btnTag1 = new Button(this);
RelativeLayout.LayoutParams btnTag1Param = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
btnTag1Param.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
btnTag1.setText("Go to " + json2.getString(KEY_PLATENUMBER));
btnTag1Param.setMargins(10, 10, 10, 10);
btnTag1.setBackgroundResource(R.drawable.dashboard_post);
btnTag1.setTextColor(getResources().getColor(R.color.white));
btnTag1.setTypeface(Typeface.DEFAULT_BOLD);
btnTag1.setPadding(8, 5, 8, 5);
btnTag1.setId(verify);
commentBoxButtons.addView(btnTag1, btnTag1Param);
Button btnTag2 = new Button(this);
RelativeLayout.LayoutParams btnTag2Param = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
btnTag2Param.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
btnTag2.setText("Go to " + json2.getString(KEY_USERNAME));
btnTag2Param.setMargins(10, 10, 10, 10);
btnTag2.setTypeface(Typeface.DEFAULT_BOLD);
btnTag2.setBackgroundResource(R.drawable.dashboard_post);
btnTag2.setTextColor(getResources().getColor(R.color.white));
btnTag2.setPadding(8, 5, 8, 5);
btnTag2.setId(verify2);
commentBoxButtons.addView(btnTag2, btnTag2Param);
verify2 = verify2 + 1;
verify = verify + 1;
offsetNumber = json2.getString(KEY_OFFSET_NUMBER);
commentCycle = commentCycle + 1;
}//end while
}//end if comment number is less than or equal to 15
//if comment number is greater than 15
if(numberOfComments2 > 15){
int commentCycle2 = 0;
while(commentCycle2 <= 15){
commentCycle2 = commentCycle2 + 1;
JSONObject json2 = CollectComments.collectComments(usernameforcomments, offsetNumber);
LinearLayout commentBox = new LinearLayout(this);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
commentBox.setBackgroundResource(R.drawable.comment_box_bg);
layoutParams.setMargins(0, 10, 0, 10);
commentBox.setPadding(0,0,0,10);
commentBox.setOrientation(LinearLayout.VERTICAL);
linear.addView(commentBox, layoutParams);
RelativeLayout commentBoxHeader = new RelativeLayout(this);
commentBoxHeader.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
commentBoxHeader.setBackgroundResource(R.drawable.comment_box_bg);
commentBoxHeader.setBackgroundResource(R.drawable.comment_box_header);
commentBox.addView(commentBoxHeader);
TextView usernameView = new TextView(this);
usernameView.setText("Posted by: " + json2.getString(KEY_USERNAME));
RelativeLayout.LayoutParams usernameViewParam = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
usernameViewParam.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
usernameView.setTextColor(getResources().getColor(R.color.white));
usernameView.setPadding(5, 5, 10, 5);
usernameView.setTypeface(Typeface.DEFAULT_BOLD);
commentBoxHeader.addView(usernameView, usernameViewParam);
TextView commentView = new TextView(this);
commentView.setText(json2.getString(KEY_COMMENT));
LinearLayout.LayoutParams commentViewParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
commentViewParams.setMargins(20, 10, 20, 20);
commentView.setBackgroundResource(R.drawable.comment_bg);
commentView.setTextColor(getResources().getColor(R.color.black));
commentBox.addView(commentView, commentViewParams);
TextView descriptionView = new TextView(this);
descriptionView.setText(json2.getString(KEY_COMMENT));
descriptionView.setPadding(20, 10, 20, 20);
descriptionView.setLayoutParams(new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
descriptionView.setTextColor(getResources().getColor(R.color.black));
commentBox.addView(descriptionView);
RelativeLayout commentBoxButtons = new RelativeLayout(this);
RelativeLayout.LayoutParams commentBoxButtonsParam = new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
commentBox.addView(commentBoxButtons, commentBoxButtonsParam);
Button btnTag1 = new Button(this);
RelativeLayout.LayoutParams btnTag1Param = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
btnTag1Param.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
btnTag1.setText("Go to " + json2.getString(KEY_PLATENUMBER));
btnTag1Param.setMargins(10, 10, 10, 10);
btnTag1.setBackgroundResource(R.drawable.dashboard_post);
btnTag1.setTextColor(getResources().getColor(R.color.white));
btnTag1.setTypeface(Typeface.DEFAULT_BOLD);
btnTag1.setPadding(8, 5, 8, 5);
btnTag1.setId(verify);
commentBoxButtons.addView(btnTag1, btnTag1Param);
Button btnTag2 = new Button(this);
RelativeLayout.LayoutParams btnTag2Param = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
btnTag2Param.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
btnTag2.setText("Go to " + json2.getString(KEY_USERNAME));
btnTag2Param.setMargins(10, 10, 10, 10);
btnTag2.setTypeface(Typeface.DEFAULT_BOLD);
btnTag2.setBackgroundResource(R.drawable.dashboard_post);
btnTag2.setTextColor(getResources().getColor(R.color.white));
btnTag2.setPadding(8, 5, 8, 5);
btnTag2.setId(verify2);
commentBoxButtons.addView(btnTag2, btnTag2Param);
verify2 = verify2 + 1;
verify = verify + 1;
offsetNumber = json2.getString(KEY_OFFSET_NUMBER);
commentCycle = commentCycle + 1;
}//end while cycle <= 15
db.resetOffsetTable();
db.addOffset(Integer.parseInt(offsetNumber));
}//end if comment number is greater than 15
}//end if key is == 1
else{
// Error in registration
registerErrorMsg.setText(json.getString(KEY_ERROR_MSG));
}//end else
}//end if
} //end try
catch (JSONException e) {
e.printStackTrace();
}//end catch
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
}
}
答案 0 :(得分：0)
AsyncTask未定义findViewById方法。检查参考页面以查看可以使用的方法。 Activity类会有这样的，所以您可能想在AsyncTask内创建Activity或将视图传递给它。
如果你要创建一个AsyncTask内部类，那么你可以：
registerErrorMsg = (TextView) YourActivity.this.findViewById(R.id.collectComment_error);
答案 1 :(得分：0)
你得到什么错误？ 您的AsyncTask类是否在Activity类之外？
如果是，正如Voicu所说，你应该在你的Activity中创建AsyncTask作为内部类。完成后，您可以使用findViewById（）方法。看看下面的例子：
public class MyActivity extends Activity
{
//Some code
public class commentAsync extends AsyncTask<String, String, String>
{
//Hurray! Can use findViewById() here!
}
//Some more code
}
如果没有，我正在等待更多信息。
的更新： 的
回答你的第一条评论，这对我很有用：
public class A extends Activity {
public class B
{
}
class C
{
}
}
我不确定为什么它不适合你，但我记得我之前有类似的问题...