Android dynamic pie chart example code

For the requirements in the project, the mpandroidchart library was found at that time, which can be implemented, but it's just a requirement. I don't feel very comfortable referring to such a large library. I plan to customize one myself.

1、 Effect drawing first

Update graph

2、 GitHub

Code address, welcome to correct https://github.com/MNXP/XPPieChart

3、 Train of thought

1. Hollow diagram (draw a small circle in the center of a large circle) 2. Calculate the angle according to the data 3. Obtain the current painted angle according to the animation 4. Obtain the color used by paint according to the current angle 5. Dynamically paint the parts to be painted and the parts already painted (the most important)

4、 Realize

1. Hollow diagram (draw a small circle in the center of a large circle) initialization data

2. Calculate the angle according to the data

Use recursion to ensure that the sum of the values of cakevalues must be 100, and then calculate the angle according to the value

3. Gets the currently painted angle from the animation

Curangle is the current drawing angle, and drawarc () is the drawing method

4. Gets the color used by paint based on the current angle

Calculate the current number of items according to the current angle through paint. SetColor (color. Parsecolor (cakevalues. Get (colorindex). Getcolors()); To set the color of the paint

5. Dynamically draw the part to be drawn and the part already drawn

The most important step, my needs are 4 categories, with different colors

Draw the sector of the current color, the starting position of curstartangle sector, and the ending position of cursweetangle sector

Draw the fan that has been drawn. Judge the drawn sector according to curitem

Draw a circle in the center

6. Special attention

Isfirst determines whether it is enough to draw for the first time (after drawing, press home to enter the background and enter again. Dynamic drawing is not required)

Isdrawbyanim determines whether animation is required

Drawcake() draws a pie chart statically

to update

Add stereo effect and extract configuration parameters

Used in XML

The above is a simple implementation of dynamic drawing pie chart, which needs to be improved. I hope it will be helpful for everyone's learning, and I hope you can support programming tips.