measurement

If I call getMeasuredWidth() or getWidth() for layout in onResume they return 0

由 删除回忆录丶 提交于 2019-11-26 22:21:04
If I call getMeasuredWidth() or getWidth() for layout in onResume they returns 0. I think that view it's not drawn yet in this moment. Also I think that I need to put getMeasuredWidth() or getWidth() in callback method called after layout is drawn and view measurements are known. What android callback method should I use? Adorjan Princz You cannot use the width / height / getMeasuredWidth / getMeasuredHeight on a View before the system renders it (typically from onCreate / onResume ). Simple solution for this is to post a Runnable to the layout. The runnable will be executed after the View has

how do we investigate how many times a browser is doing reflows?

由 江枫思渺然 提交于 2019-11-26 20:24:12
问题 Is there a web developer functionality/tool that allows us to know how many times a browser is doing reflows? basically I want to have some sort of feedback/information. I don't know how it will be, but perhaps some sort of performance graph that shows the timeline (akin to Google's Speed Tracer) so I can investigate when suddenly at a point the browser is doing an insane amount of reflows so I can point out hey here's a bottleneck, there got to be a bug/bad implementation of something here

Why is Graphics.MeasureString() returning a higher than expected number?

由 纵饮孤独 提交于 2019-11-26 18:24:53
I'm generating a receipt and am using the Graphics object to call the DrawString method to print out the required text. graphics.DrawString(string, font, brush, widthOfPage / 2F, yPoint, stringformat); This works fine for what I needed it to do. I always knew what I was printing out, so I could manually trim any strings so it would fit properly on 80mm receipt paper. Then I had to add an extra bit of functionality that would make this more flexible. The user could pass in strings that would be added to the bottom. Since I didn't know what they were going to put, I just created my own word wrap

Pixel to Centimeter?

由 折月煮酒 提交于 2019-11-26 17:27:57
问题 I just want to know if the pixel unit is something that doesn't change, and if we can convert from pixels to let's say centimeters ? 回答1: Similar to this question which asks about points instead of centimeters. There are 72 points per inch and there are 2.54 centimeters per inch, so just substitute 2.54 for 72 in the answer to that question. I'll quote and correct my answer here: There are 2.54 centimeters per inch; if it is sufficient to assume 96 pixels per inch, the formula is rather

Measuring Java execution time, memory usage and CPU load for a code segment

由 点点圈 提交于 2019-11-26 12:59:44
问题 For a particular segment of Java code, I\'d like to measure: Execution time (most likely thread execution time ) Memory usage CPU load (specifically attributable to the code segment) I\'m a relative Java novice and am not familiar with how this might be achieved. I\'ve been referred to JMX, however I\'m not sure how that might be used, and JMX looks a bit \'heavy\' for what I\'m looking to do. Ideally I\'d like some measurement class that can be told what I would like to measure, with the

Difference between android dimension: pt and dp

由 对着背影说爱祢 提交于 2019-11-26 11:52:16
问题 The documentation says that 160 dp (density-independent) equals 1 inch. And 72 pt is also 1 inch. So I don\'t see why android define a dp measurement while it seems to work the same as points. Can anybody explain that? Why should I use dp if I can use pt? 回答1: The Android documentation used to incorrectly state that 160 dp always equals 1 inch regardless of screen density. This was reported as a bug which was accepted and the documentation updated. From the updated documentation: 160 dp will

simplest tool to measure C program cache hit/miss and cpu time in linux?

由 回眸只為那壹抹淺笑 提交于 2019-11-26 10:09:32
问题 I\'m writing a small program in C, and I want to measure it\'s performance. I want to see how much time do it run in the processor and how many cache hit+misses has it made. Information about context switches and memory usage would be nice to have too. The program takes less than a second to execute. I like the information of /proc/[pid]/stat, but I don\'t know how to see it after the program has died/been killed. Any ideas? EDIT: I think Valgrind adds a lot of overhead. That\'s why I wanted

If I call getMeasuredWidth() or getWidth() for layout in onResume they return 0

由 北战南征 提交于 2019-11-26 08:18:08
问题 If I call getMeasuredWidth() or getWidth() for layout in onResume they returns 0. I think that view it\'s not drawn yet in this moment. Also I think that I need to put getMeasuredWidth() or getWidth() in callback method called after layout is drawn and view measurements are known. What android callback method should I use? 回答1: You cannot use the width / height / getMeasuredWidth / getMeasuredHeight on a View before the system renders it (typically from onCreate / onResume ). Simple solution

Font size relative to the user's screen resolution?

由 十年热恋 提交于 2019-11-26 07:58:25
问题 I have a fluid website and the menu is 20% of its width. I want the font size of the menu to be measured properly so it always fits the width of the box and never wrap to the next line. I was thinking of using \"em\" as a unit but it is relative to the browser\'s font size, so when I change resolutions the font size stays the same. Tried also pts and percentages. Nothing works as I need it... Give me a hint of how to proceed, please. 回答1: @media screen and (max-width : 320px) { body or

Easily measure elapsed time

由 試著忘記壹切 提交于 2019-11-26 00:07:24
问题 I am trying to use time() to measure various points of my program. What I don\'t understand is why the values in the before and after are the same? I understand this is not the best way to profile my program, I just want to see how long something take. printf(\"**MyProgram::before time= %ld\\n\", time(NULL)); doSomthing(); doSomthingLong(); printf(\"**MyProgram::after time= %ld\\n\", time(NULL)); I have tried: struct timeval diff, startTV, endTV; gettimeofday(&startTV, NULL); doSomething();
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