自定义view

主要实现：点击button之后数字和自定义圆的大小一直增加，后期可以拖动。
建一个attrs的xml（内容如下）：

<?xml version="1.0" encoding="utf-8"?><resources>    <attr name="radio" format="integer"/>    <attr name="Mywidth" format="integer"/>    <declare-styleable name="CustomView">        <attr name="radio"/>        <attr name="Mywidth"/>    </declare-styleable></resources>

自定义view的类CustomView：

public class CustomView extends GridView {    private int index = 0;    private int radio;    private int mywidth;    public CustomView(Context context) {        this(context, null);    }    public CustomView(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public CustomView(Context context, AttributeSet attrs, int defStyleAttr) {        this(context, attrs, defStyleAttr, 0);        //改变角度和text(就是数字)        TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CustomView, defStyleAttr, 0);        int n = a.getIndexCount();        for (int i = 0; i < n; i++) {            int attr = a.getIndex(i);            switch (attr) {                case R.styleable.CustomView_radio:                    radio = a.getInteger(attr, 0);                    break;            }        }        a.recycle();    }    public CustomView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {        super(context, attrs, defStyleAttr, defStyleRes);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);    }    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        super.onLayout(changed, l, t, r, b);    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        //画笔paint(圆的)        Paint paint = new Paint();        paint.setColor(Color.RED);        //数字        Paint paint1 = new Paint();        paint1.setColor(Color.GREEN);        paint1.setTextSize(50);        Paint paint2 = new Paint();        paint2.setColor(Color.YELLOW);        //空心的        paint2.setStyle(Paint.Style.STROKE);        //圆的宽度        paint2.setStrokeWidth(mywidth);        canvas.drawCircle(300f, 300, radio, paint);        canvas.drawText(index + "", 230f, 300f, paint1);        canvas.drawCircle(300f, 300, 130, paint2);    }    public void setInteger(int radio) {        this.radio = radio;    }    public void setText(int text) {        this.index = text;    }    private int lastX = 0;    private int lastY = 0;    @Override    public boolean onTouchEvent(MotionEvent event) {        switch (event.getAction()) {            case MotionEvent.ACTION_DOWN:                lastX = (int) event.getRawX();                lastY = (int) event.getRawY();                break;            case MotionEvent.ACTION_MOVE:               if (index == 100){                int dx = (int) event.getRawX() - lastX;                int dy = (int) event.getRawY() - lastY;                int left = getLeft() + dx;                int top = getTop() + dy;                int right = getRight() + dx;                int bottom = getBottom() + dy;                layout(left, top, right, bottom);                lastX = (int) event.getRawX();                lastY = (int) event.getRawY();               }                break;            case MotionEvent.ACTION_UP:                break;            default:                break;        }        return true;    }}

activity-main类的代码

    <Button        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:id="@+id/btn"        android:text="点击"        />    <com.bwie.myweektest.CustomView        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_centerInParent="true"        android:id="@+id/cv"        app:Mywidth="30"        app:radio="10"        >    </com.bwie.myweektest.CustomView>

Mainactivity类

public class MainActivity extends AppCompatActivity {    private CustomView cv;    private Button button;    private Handler handler = new Handler() {        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);            switch (msg.what) {                case 1:                    cv.setInteger(25);                    cv.invalidate();                    break;                case 2:                    cv.setInteger(50);                    cv.invalidate();                    break;                case 3:                    cv.setInteger(75);                    cv.invalidate();                    break;                case 4:                    cv.setInteger(100);                    cv.invalidate();                    break;                case 5:                    cv.setInteger(125);                    cv.invalidate();                    break;                case 6:                    Object obj = msg.obj;                    cv.setText((Integer) obj);                    cv.invalidate();                    break;            }        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();    }    private void initView() {        cv = (CustomView) findViewById(R.id.cv);        button = (Button) findViewById(R.id.btn);        button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                new Thread() {                    @Override                    public void run() {                        super.run();                        for (int i = 1; i < 6; i++) {                            try {                                for (int j = (20 * i) - 20; j < (20 * i) + 1; j++) {                                    sleep(50);                                    Message message = new Message();                                    message.obj = j;                                    message.what = 6;                                    handler.sendMessage(message);                                }                                handler.sendEmptyMessage(i);                            } catch (InterruptedException e) {                                e.printStackTrace();                            }                        }                    }                }.start();            }        });    }}

就OK了 ^_^。