Category：Mobile Development
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Time：2020-2-23
Transfer out: https://www.cnblogs.com/xiaobajiu/p/10799962.html Using nsproxy as a surrogate, proxy, and multi inheritance is essentially used to forward messages to the real person. Observe the header file. Nsproxy implements the following methods: +(class) class; // class methods should not override //General message forwarding 1 -(void) forwardinvocation: (nsinvocation *) invocation; // in fact, it is not implemented […]
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Time：2020-2-23
What is a memory leak? It is the memory that has not been recycled for various reasons and still resides in the memory. What is the impact of a memory leak? A small memory leak may cause the whole application to jam or even crash. Example: Toast.makeText(MainActivity.this,”Hello”,Toast.LENGTH_SHORT).show(); This code may leak memory. Why is […]
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Time：2020-2-23
dp(dip): Device independent pixels. Different devices have different display effects, which is related to the device hardware. Generally, we recommend using this in order to support WVGA, HVGA and QVGA, not pixel dependent. DP is also called dip, which is basically similar to sp. DP or SP can be used when setting properties such as […]
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Time：2020-2-23
You may notice that the top picture of some app’s tableview will expand as you stretch. Here are my thoughts Original image: Design sketch: Please attach the code below. The picture here is not added to the header of tabview #define SCREEN_W [UIScreen mainScreen].bounds.size.width #define SCREEN_H [UIScreen mainScreen].bounds.size.height #Define top 200 // top reserved #import […]
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Time：2020-2-22
Uipickerview is a very common UI control, which is necessary for various shopping platforms to select addresses. Let’s talk about the specific use First, uipickerview is created. Like most controls, it allocates memory and sets the location size. It is important to set up the agent and data source and obey the agent and data […]
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Time：2020-2-22
Preface
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Time：2020-2-22
The effect is as follows: The layout file activity main.xml is as follows: <RelativeLayout xmlns:android=”http://schemas.android.com/apk/res/android” xmlns:tools=”http://schemas.android.com/tools” android:layout_width=”match_parent” android:layout_height=”match_parent” android:paddingBottom=”@dimen/activity_vertical_margin” android:paddingLeft=”@dimen/activity_horizontal_margin” android:paddingRight=”@dimen/activity_horizontal_margin” android:paddingTop=”@dimen/activity_vertical_margin” tools:context=”.MainActivity” > <ImageSwitcher android:id=”@+id/imageSwitcher” android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:layout_weight=”2″ android:paddingTop=”30px” > </ImageSwitcher> <Gallery android:id=”@+id/gallery1″ android:layout_width=”match_parent” android:layout_height=”wrap_content” android:layout_weight=”1″ android:spacing=”5px” android:unselectedAlpha=”0.6″ /> </RelativeLayout> Mainactivity.java code is as follows: import android.app.ActionBar.LayoutParams; import android.app.Activity; import android.os.Bundle; import android.view.View; import […]
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Time：2020-2-22
The example of this article shares the specific code of the zoom effect display of IOS dropdown image for your reference. The specific content is as follows #import “ViewController.h” #define kScreenbounds [UIScreen mainScreen].bounds #define kScreenWidth [UIScreen mainScreen].bounds.size.width #define kScreenHeight [UIScreen mainScreen].bounds.size.height //Macro defines a height #define pictureHeight 200 @interface ViewController ()<UITableViewDataSource, UITableViewDelegate> @property (nonatomic, strong) […]
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Time：2020-2-21
1. Introduction to GCD What is GCD? Let’s take a look at the explanation of Baidu Encyclopedia and understand the concept From Baidu Encyclopedia Grand Central Dispatch(GCD)It is a new solution of multi-core programming developed by apple. It is mainly used to optimize applications to support multi-core processors and other symmetric multi-processing systems. It is […]
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Time：2020-2-21
Java plug-ins are the basis of building JVM projects, which add many capabilities to the projects, such as compiling, testing, packaging, publishing, etc. Many plug-ins are implemented based on Java plug-ins, such as Android plug-ins. usage Using the ID application plug-in plugins { id ‘java’ } Source sets Java plug-in introduces the concept of source […]
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Time：2020-2-21
When using the listview component to display list data, sometimes we need to change the data in the list, as follows: 1. Reset adapter for listview component This method recreates the listview, which is inefficient. 2. Using the methods in the adapter /** * Notifies the attached observers that the underlying data has been changed […]
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Time：2020-2-21
Recently, in the work of project security, it is necessary to do the function of preventing users from screenshots and recording on sensitive pages in app. I have looked up some information on the Internet, and made a note here for future reference. Screen capture status acquisition The method of editing the latest photos in […]
