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java annotations are easy to use

java annotations are easy to use Annotations have been used throughout the development process, and today I finally want to look at the implementation of annotations.Drive directly // Custom Notes // Annotation has been implemented here // Note that comments are only valid in the form of reflection calls @Retention(value = RetentionPolicy.RUNTIME) @Target(value = {ElementType.METHOD,ElementType.FIELD}) public @interface InterfaceTest...

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Problems with Android setPolyToPoly (2)

Problems with Android setPolyToPoly (2) Question: The question is still the last one ( Problems with Android setPolyToPoly (1) ) Problem, which was solved with hardware acceleration in the previous article, but he may have black edges around the drawn quadrilateral on some mobile phones. It is suspected that the transparency problem was solved after matrix acted on canvas. Solution: Matx has problems working on canvas on some...

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vue+vuex+axios+echarts Draw a dynamically updated map of China

I. Build projects and install plug-ins # Install vue-cli npm install vue-cli -g # Initialize project vue init webpack china-map # Cut into Catalog cd china-map # Installation Project Dependency npm install # Install vuex npm install vuex --save # Install axios npm install axios --save # Install ECharts npm install echarts --save II. Project structure ├── index.html ├── main.js ├── components │ └──...

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vue+vuex+axios+echarts Draw a dynamically updated map of China

I. Build projects and install plug-ins # Install vue-cli npm install vue-cli -g # Initialize project vue init webpack china-map # Cut into Catalog cd china-map # Installation Project Dependency npm install # Install vuex npm install vuex --save # Install axios npm install axios --save # Install ECharts npm install echarts --save II. Project structure ├── index.html ├── main.js ├── components │ └──...

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Mongodb update array $pull modifier

1. $pull modifier deletes qualifying elements from the array in the following format: { $pull: { <field1>: <value|condition>, <field2>: <value|condition>, ... } } 2. Specify a value to delete all lists Give a document under a stores collection { _id: 1, fruits: [ "apples", "pears", "oranges", "grapes", "bananas" ], vegetables: [ "carrots", "celery", "squash", "carrots" ] } { _id: 2, fruits:...

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JQuery Source Understanding (1)

When you look at the JQuery source code, you can use StackOverFlow to search for answers to related questions and often find satisfactory answers quickly. 1. Extend JQuery to a global object Extend JQuery to a global object so that you can use $directly in your js code to represent JQuery. // Expose jQuery to the global object window.jQuery = window.$ = jQuery; 2. JQuery prototype object jQuery.fn = jQuery.prototype = {···} //...

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vue property binding and interaction

vue directive binding properties vue binds attributes by directive v-bind, src/width/height/title, such as v-bind:src='''can be abbreviated as: src=''', the same v-Bind:widthWait a moment, abbreviated as width,:height <script src="https://unpkg.com/vue/dist/vue.js"></script> <body> <div id="box"> <img v-bind:src="a" :width = 'width' :heigth="height"> </div> </body> <script> new...