电商项目实战 自定义view 画图 柱状图 点击按钮添加数据

主页面

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    main_myview = findViewById(R.id.main_myview);
    edit_score = findViewById(R.id.edit_score);
    edit_name =findViewById(R.id.edit_name);
    Button btn_add=findViewById(R.id.btn_add);
    btn_add.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String score = edit_score.getText().toString();
            String name = edit_name.getText().toString();
            int cj = Integer.parseInt(score);
            user = new User(cj, name);
            Toast.makeText(MainActivity.this, user.toString()+"",Toast.LENGTH_SHORT).show();
            main_myview.addUser(user);
        }
    });
}

自定义view

public class MyView extends View {
private static final String TAG = "MyView";
private Paint mLinePaint,mTextPaint,mRectPaint;
private List<User> list=new ArrayList<>();
private User user;
private View view;
private EditText edit_score;
private EditText edit_name;

public MyView(Context context) {
    super(context);
    init();
}
public MyView(Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
    init();
}

public MyView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    init();
}

public void init() {
    mLinePaint = new Paint();
    mLinePaint.setColor(Color.BLUE);
    mLinePaint.setStyle(Paint.Style.STROKE);
    mLinePaint.setStrokeWidth(2);

    mRectPaint = new Paint();
    mRectPaint.setColor(Color.RED);
    mRectPaint.setStyle(Paint.Style.FILL);


    mTextPaint = new Paint();
    mTextPaint.setColor(Color.BLUE);
    mTextPaint.setStyle(Paint.Style.STROKE);
    mTextPaint.setTextSize(30);
}

public  void addUser(User user) {
    if(user!=null){
        list.add(user);
        this.invalidate();//刷新
    }
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    //坐标轴
    canvas.drawLine(100,500,500,500,mLinePaint);
    canvas.drawLine(100,100,100,500,mLinePaint);
    //初始化数据

    //坐标
    for (int i = 0; i <5; i++) {
        int a=i*100;
        canvas.drawText(a+"",25,500-100*i,mTextPaint);
    }
    for (int i = 0; i <list.size() ; i++) {
        canvas.drawText(list.get(i).getName(),100+25+100*i,550,mTextPaint);
        Log.d(TAG, "onDraw: +++++++"+i);
    }
    //填充

    for (int i = 0; i <list.size() ; i++) {
        Rect rect = new Rect();
        int a=i*100;
        rect.left=100+25+a;
        rect.right=100+100+a;
        rect.bottom=500;
        rect.top=rect.bottom-list.get(i).getScore();
        canvas.drawRect(rect,mRectPaint);
    }
}
}