Here is the code. If a View has been long clicked, I want this loop to rerun by making i = 0. But the if statement after setOnLongClickListener only gets executed once in the beginning and not after the view has been long clicked.
final hasLongClicked[] = {false};
for(int i = 0; i < mLLayout.getChildCount(); i++){
// tried declaring hasLongClicked[] here but no avail
View child = mLLayout.getChildAt(i);
child.setOnLongClickListener(new View.OnLongClickListener(){
#Override
public boolean onLongClick(View v) {
//Some stuff
hasLongClicked[0] = true;
return false;
}
});
if(hasLongClicked[0])
i = 0;
}
How do I do get through this? On a separate note, is this a good way to setOnLongClickListeners to all child views of a linear layout?
Help is much appreciated. Thank you
I solved it by making a function out of it and calling itself whenever the event has been handledas follows:
private void discardEvents(LinearLayout mLLayout) {
for(int i = 0; i < mLLayout.getChildCount(); i++){
View child = mLLayout.getChildAt(i);
child.setOnLongClickListener(new View.OnLongClickListener(){
#Override
public boolean onLongClick(View v) {
//Do your stuff
discardEvents(mLLayout);
return false;
}
});
}
}
Although I would like to know if this would cause any problems/ has hidden bugs.
Related
I am writing a function to compare if the string contains a list of keywords (string list)
I implement it as a callback function from another widget in flutter.
The callback function works, however, the compare method inside callback function doesn't work.
Please send help /.\
void callback(List<String> filterKeyword) {
setState(() {
this.filterKeyword = filterKeyword;
});
resFiltered.clear();
res.forEach((res) {
if (compareString(res.type, this.filterKeyword)) {
resFiltered.add(res);
}
});
}
bool compareString(String inputStr, List<String> items) {
if (items.length == 0) {
return true;
}
for(int i = 0; i < items.length; i++) {
if(inputStr.contains(items[i])) {
return true;
}
}
return false;
}
I changed it little bit to return string and implemented added to flutter default project as text widget. And it worked. You have to ensure if the parameters where indeed as you written... I notice that this is case sensitive...
I hope it will help!
I have a datagridview which is being populated by a DataTable through DataSource and i am using a backgroundworker for formatting of cells (back color and forecolor of cells) in datagridview.
BackgroundWorker bw = new BackgroundWorker();
private void Frm_Find_Load(object sender, EventArgs e)
{
bw.WorkerSupportsCancellation = true;
bw.DoWork += new DoWorkEventHandler(bw_DoWork);
bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
}
void bw_DoWork(object sender, DoWorkEventArgs e)
{
CheckForValidValues();
}
public bool CheckForValidValues()
{
dgv.Invoke((MethodInvoker)delegate()
{
for (int i = 0; i < Dt.Rows.Count; i++)
{
if (Dt.Rows[0]["Name"].ToString() == Value)
{
dgv.Rows[i].Cells["Name"].Style.BackColor = Color.FromArgb(255, 192, 192);
}
else
{
dgv.Rows[i].Cells["Name"].Style.BackColor = Color.White;
}
progressBar1.Invoke((MethodInvoker)(() => progressBar1.Value++));
}
});
this.Invoke((MethodInvoker)delegate()
{
BtnShow.Enabled = true;
dgv.Enabled = true;
});
}
private void btnSave_Click(object sender, EventArgs e)
{
if (bw.IsBusy == false)
{
progressBar1.Visible = true;
progressBar1.Value = 0;
BtnShow.Enabled = false;
dgv.Enabled = false;
progressBar1.Maximum = dgv.Rows.Count;
bw.RunWorkerAsync();
}
}
while the whole process goes down the DataGridView remains Enabled=false so that user cant change any values in datagridview.
There is usually 15,000 rows in the datagridview and that many rows to format, this takes time that is why I use a backgroundworker for it and it works perfectly fine BUT when the user tries to press the enabled false datagridview couple of times, the main thread becomes unresponsive and the progressbar freezes.
Can anyone guide me how to deal with it?
You are running the whole code using Invoke. It means you are switching to UI thread and the code is running in UI thread. Since the code is a time-consuming for loop, then it's blocking UI thread.
Instead of using a BackgroundWorker, to format cells, it's better to use CellFormatting event:
private void dgv_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
//If this is header cell or new row, do nothing
if (e.RowIndex < 0 || e.ColumnIndex < 0 || e.RowIndex == dgv.NewRowIndex)
return;
//If formatting your desired column, perform validation
if (e.ColumnIndex == dgv.Columns["Name"].Index)
{
// Perform validation and change cell back color here.
}
}
Maybe try to disable the Button when it get clicked until the job done?.
Lets say your Button name is Button1,
when the user click on the Enabled false data grid view, use Button.enabled=false, then when the job is done use Button.enabled=true
hope that helps!
I am trying to get multithreading more unraveled in my head. I made these three classes.
A global variable class
public partial class globes
{
public bool[] sets = new bool[] { false, false, false };
public bool boolChanged = false;
public string tmpStr = string.Empty;
public int gcount = 0;
public bool intChanged = false;
public Random r = new Random();
public bool gDone = false;
public bool first = true;
}
Drop in point
class Driver
{
static void Main(string[] args)
{
Console.WriteLine("start");
globes g = new globes();
Thread[] threads = new Thread[6];
ParameterizedThreadStart[] pts = new ParameterizedThreadStart[6];
lockMe _lockme = new lockMe();
for (int b = 0; b < 3; b++)
{
pts[b] = new ParameterizedThreadStart(_lockme.paramThreadStarter);
threads[b] = new Thread(pts[b]);
threads[b].Name = string.Format("{0}", b);
threads[b].Start(b);
}
}
}
And then my threading class
class lockMe
{
#region Fields
private string[] words = new string[] {"string0", "string1", "string2", "string3"};
private globes g = new globes();
private object myKey = new object();
private string[] name = new string[] { String.Empty, String.Empty, String.Empty };
#endregion
#region methods
// first called for all threads
private void setName(Int16 i)
{
Monitor.Enter(myKey);
{
try
{
name[i] = string.Format("{0}:{1}", Thread.CurrentThread.Name, g.r.Next(100, 500).ToString());
}
finally
{
Monitor.PulseAll(myKey);
Monitor.Exit(myKey);
}
}
}
// thread 1
private void changeBool(Int16 a)
{
Monitor.Enter(myKey);
{
try
{
int i = getBools();
//Thread.Sleep(3000);
if (g.gcount > 5) { g.gDone = true; return; }
if (i == 3) resets();
else { for (int x = 0; x <= i; i++) { g.sets[x] = true; } }
Console.WriteLine("Thread {0} ran through changeBool()\n", name[a]);
}
finally
{
Monitor.PulseAll(myKey);
Monitor.Exit(myKey);
}
}
}
// thread 2
private void changeInt(Int16 i)
{
Monitor.Enter(myKey);
{
try
{
g.gcount++;
//Thread.Sleep(g.r.Next(1000, 3000));
Console.WriteLine("Thread {0}: Count is now at {1}\n", name[i], g.gcount);
}
finally
{
Monitor.PulseAll(myKey);
Monitor.Exit(myKey);
}
}
}
// thread 3
private void printString(Int16 i)
{
Monitor.Enter(myKey);
{
try
{
Console.WriteLine("...incoming...");
//Thread.Sleep(g.r.Next(1500, 2500));
Console.WriteLine("Thread {0} printing...{1}\n", name[i], words[g.r.Next(0, 3)]);
}
finally
{
Monitor.PulseAll(myKey);
Monitor.Exit(myKey);
}
}
}
// not locked- called from within a locked peice
private int getBools()
{
if ((g.sets[0] == false) && (g.sets[1] == false) && (g.sets[2] == false)) return 0;
else if ((g.sets[0] == true) && (g.sets[1] == false) && (g.sets[2] == false)) return 1;
else if ((g.sets[2] == true) && (g.sets[3] == false)) return 2;
else if ((g.sets[0] == true) && (g.sets[1] == true) && (g.sets[2] == true)) return 3;
else return 99;
}
// should not need locks- called within locked statement
private void resets()
{
if (g.first) { Console.WriteLine("FIRST!!"); g.first = false; }
else Console.WriteLine("Cycle has reset...");
}
private bool getStatus()
{
bool x = false;
Monitor.Enter(myKey);
{
try
{
x = g.gDone;
}
finally
{
Monitor.PulseAll(myKey);
Monitor.Exit(myKey);
}
}
return x;
}
#endregion
#region Constructors
public void paramThreadStarter(object starter)
{
Int16 i = Convert.ToInt16(starter);
setName(i);
do
{
switch (i)
{
default: throw new Exception();
case 0:
changeBool(i);
break;
case 1:
changeInt(i);
break;
case 2:
printString(i);
break;
}
} while (!getStatus());
Console.WriteLine("fin");
Console.ReadLine();
}
#endregion
}
So I have a few questions. The first- is it better to have my global class set like this? Or should I be using a static class with properties and altering them that way? Next question is, when this runs, at random one of the threads will run, pulse/exit the lock, and then step right back in (sometimes like 5-10 times before the next thread picks up the lock). Why does this happen?
Each thread is given a certain amount of CPU time, I doubt that one particular thread is getting more actual CPU time over the others if you are locking all the calls in the same fashion and the thread priorities are the same among the threads.
Regarding how you use your global class, it doesn't really matter. The way you are using it wouldn't change it one way or the other. Your use of globals was to test thread safety, so when multiple threads are trying to change shared properties all that matters is that you enforce thread safety.
Pulse might be a better option knowing that only one thread can actually enter, pulseAll is appropriate when you lock something because you have a task to do, once that task is complete and won't lock the very next time. In your scenario you lock every time so doing a pulseAll is just going to waste cpu because you know that it will be locked for the next request.
Common example of when to use static classes and why you must make them thread safe:
public static class StoreManager
{
private static Dictionary<string,DataStore> _cache = new Dictionary<string,DataStore>(StringComparer.OrdinalIgnoreCase);
private static object _syncRoot = new object();
public static DataStore Get(string storeName)
{
//this method will look for the cached DataStore, if it doesn't
//find it in cache it will load from DB.
//The thread safety issue scenario to imagine is, what if 2 or more requests for
//the same storename come in? You must make sure that only 1 thread goes to the
//the DB and all the rest wait...
//check to see if a DataStore for storeName is in the dictionary
if ( _cache.ContainsKey( storeName) == false )
{
//only threads requesting unknown DataStores enter here...
//now serialize access so only 1 thread at a time can do this...
lock(_syncRoot)
{
if (_cache.ContainsKey(storeName) == false )
{
//only 1 thread will ever create a DataStore for storeName
DataStore ds = DataStoreManager.Get(storeName); //some code here goes to DB and gets a DataStore
_cache.Add(storeName,ds);
}
}
}
return _cache[storeName];
}
}
What's really important to see is that the Get method only single threads the call when there is no DataStore for the storeName.
Double-Check-Lock:
You can see the first lock() happens after an if, so imagine 3 threads simultaneously run the if ( _cache.ContainsKey(storeName) .., now all 3 threads enter the if. Now we lock so that only 1 thread can enter, now we do the same exact if statement, only the very first thread that gets here will actually pass this if statement and get the DataStore. Once the first thread .Add's the DataStore and exits the lock the other 2 threads will fail the second check (double check).
From that point on any request for that storeName will get the cached instance.
So we single threaded our application only in the spots that required it.
Hi i am trying to grab a value from my threading but it seem work not so find to me course i found that my code structure are unstable enough..here is my code i name my thread class as "clsThreadCount" and below is my implementation
public volatile bool Grab = false;
public volatile int count = 0;
public void Initialization(int i)
{
count = i;
}
public void Play()
{
Grab = false;
_shouldStop = false;
ThreadTest();
}
public void Stop()
{
_shouldStop = true;
workerThread.Join(1);
workerThread.Abort();
}
private void ThreadTest()
{
workerThread = new Thread(DoWork);
workerThread.Start();
while (!workerThread.IsAlive) ;
}
private void DoWork()
{
try
{
while (!_shouldStop)
{
if (Grab)
{
count++;
Grab = false;
}
}
}
catch (Exception)
{
Play();
}
finally
{
}
}
when my program(main menu) are starting to run i will trigger the initialize function at pass the parameter as 7
ObjThreadCount.Initialization(7); // count = 7
ObjThreadCount.Play(); // the thread are running
ObjThreadCount.Grab = true; // the grab equal to true, count++ are trigger
Thread.Sleep(100); // wait awhile
lblResult.Text = ObjThreadCount.count.ToString(); // sometime i can get count++ result (e.g. 8)
ObjThreadCount.Stop(); // thread stop
sometime my program can able to get a right counting from the thread but sometime are not.
i realize at my while loop implementation there are something are missing..
something like waitone or waitautoevent..can i ignore Thread.Sleep(100) ?? what are the suitable code should i add in the while loop ?
Please help me~ :S
** sorry in the first upload i forgot to write down "volatile" into the variable
thank you..
If C# (and C and java, and probably C++), you need to declare _shouldStop and Grab as volatile.
I'm calling a powershell script from C#. The script is pretty small and is "gps;$host.SetShouldExit(9)", which list process, and then send back an exit code to be captured by the PSHost object.
The problem I have is when the pipeline has been stopped and disposed, the output reader PSHost collection still seems to be written to, and is filling up. So when I try and copy it to my own output object, it craps out with a OutOfMemoryException when I try to iterate over it. Sometimes it will except with a Collection was modified message. Here is the code.
private void ProcessAndExecuteBlock(ScriptBlock Block)
{
Collection<PSObject> PSCollection = new Collection<PSObject>();
Collection<Object> PSErrorCollection = new Collection<Object>();
Boolean Error = false;
int ExitCode=0;
//Send for exection.
ExecuteScript(Block.Script);
// Process the waithandles.
while (PExecutor.PLine.PipelineStateInfo.State == PipelineState.Running)
{
// Wait for either error or data waithandle.
switch (WaitHandle.WaitAny(PExecutor.Hand))
{
// Data
case 0:
Collection<PSObject> data = PExecutor.PLine.Output.NonBlockingRead();
if (data.Count > 0)
{
for (int cnt = 0; cnt <= (data.Count-1); cnt++)
{
PSCollection.Add(data[cnt]);
}
}
// Check to see if the pipeline has been closed.
if (PExecutor.PLine.Output.EndOfPipeline)
{
// Bring back the exit code.
ExitCode = RHost.ExitCode;
}
break;
case 1:
Collection<object> Errordata = PExecutor.PLine.Error.NonBlockingRead();
if (Errordata.Count > 0)
{
Error = true;
for (int count = 0; count <= (Errordata.Count - 1); count++)
{
PSErrorCollection.Add(Errordata[count]);
}
}
break;
}
}
PExecutor.Stop();
// Create the Execution Return block
ExecutionResults ER = new ExecutionResults(Block.RuleGuid,Block.SubRuleGuid, Block.MessageIdentfier);
ER.ExitCode = ExitCode;
// Add in the data results.
lock (ReadSync)
{
if (PSCollection.Count > 0)
{
ER.DataAdd(PSCollection);
}
}
// Add in the error data if any.
if (Error)
{
if (PSErrorCollection.Count > 0)
{
ER.ErrorAdd(PSErrorCollection);
}
else
{
ER.InError = true;
}
}
// We have finished, so enque the block back.
EnQueueOutput(ER);
}
and this is the PipelineExecutor class which setups the pipeline for execution.
public class PipelineExecutor
{
private Pipeline pipeline;
private WaitHandle[] Handles;
public Pipeline PLine
{
get { return pipeline; }
}
public WaitHandle[] Hand
{
get { return Handles; }
}
public PipelineExecutor(Runspace runSpace, string command)
{
pipeline = runSpace.CreatePipeline(command);
Handles = new WaitHandle[2];
Handles[0] = pipeline.Output.WaitHandle;
Handles[1] = pipeline.Error.WaitHandle;
}
public void Start()
{
if (pipeline.PipelineStateInfo.State == PipelineState.NotStarted)
{
pipeline.Input.Close();
pipeline.InvokeAsync();
}
}
public void Stop()
{
pipeline.StopAsync();
}
}
An this is the DataAdd method, where the exception arises.
public void DataAdd(Collection<PSObject> Data)
{
foreach (PSObject Ps in Data)
{
Data.Add(Ps);
}
}
I put a for loop around the Data.Add, and the Collection filled up with 600k+ so feels like the gps command is still running, but why. Any ideas.
Thanks in advance.
Found the problem. Named the resultant collection and the iterator the same, so as it was iterating, it was adding to the collection, and back into the iterator, and so forth. Doh!.