Android 如何在asynctask中放置json代码
我有一个连接到数据库并检索注释的json函数。该函数首先收集有多少条注释，然后while循环调用该函数，直到检索到所有注释。问题是，当我加载我的应用程序时，会出现黑屏，在Json函数完成之前不会加载其余视图。我希望json函数在后台运行。因此，应用程序将加载，评论将在后台单独加载。下面是收集所有注释的代码Android 如何在asynctask中放置json代码,android,json,android-asynctask,Android,Json,Android Asynctask,我有一个连接到数据库并检索注释的json函数。该函数首先收集有多少条注释，然后while循环调用该函数，直到检索到所有注释。问题是，当我加载我的应用程序时，会出现黑屏，在Json函数完成之前不会加载其余视图。我希望json函数在后台运行。因此，应用程序将加载，评论将在后台单独加载。下面是收集所有注释的代码 String usernameforcomments = db.getUserDetails(); registerErrorMsg =
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);
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 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
}//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
String usernameforcomments=db.getUserDetails（）；
registerErrorMsg=（TextView）findViewById（R.id.collectComment\u错误）；
int=1；
int-verify2=1；
字符串offsetNumber=“null”；
LinearLayout linear=（LinearLayout）this.findViewById（R.id.commentSection）；
UserFunctions CollectComments=新的UserFunctions（）；
JSONObject json=CollectComments.CollectComments（usernameforcomments，offsetNumber）；
int循环=1；
//查看评论
试试{
if（json.getString（KEY_SUCCESS）！=null）{
registerErrorMsg.setText（“”）；
String res2=json.getString（KEY_SUCCESS）；
如果（Integer.parseInt（res2）==1）{
String numberOfComments=json.getString（注释的键号）；
字符串offsetNumberDb=db.getOffsetNumber（）；
int numberOfComments2=Integer.parseInt（numberOfComments）-Integer.parseInt（offsetNumberDb）；
offsetNumber=offsetNumberDb；
//如果注释编号小于15或等于15
如果（numberOfComments2我不会为您重新编写代码，但您可以尝试一下，然后在遇到问题的地方发布。您可以使用doInBackground（）
以外的任何方法更新UI
元素。因此，请设置AyncTask
（）如果您需要在任务开始之前使用UI
执行某些操作，例如显示ProgressBar
，则可以将其放入onPreExecute（）
将所有JSON转换放入doInBackground（）
中，如果在获取数据时需要更新UI
，则可以使用publishProgress（）
fromdoInBackground（）
调用onProgressUpdate（）
如果您需要从doInBackground（）
返回数据，那么它将将数据作为参数返回到onPostExecute（）
，然后您可以再次更新UI
，调用活动
方法等