自定義控件 - 圈圈
Android L; Android Studio
效果:能夠自定義圓圈半徑和位置;設定點選效果;改變背景顔色
下面是demo圖
點選前: 點選後:
自定義控件一般要繼承View;寫出構造方法,并設定屬性;複寫
onDraw
方法
并在xml中配置一下
例子:
OptionCircle.java
CirclesActivity.java
activity_circle_choose.xml
這個例子沒有使用
attrs.xml
控件 OptionCircle
這裡繼承的是ImageView;設定了多個屬性,有半徑,圓心位置,背景顔色和字型顔色等等
針對這些屬性,開放set方法;友善設定屬性;可以改變這些屬性來做出一些動畫效果
構造方法中預設幾個屬性,設定畫筆,背景顔色和圓圈的半徑
onDraw
方法中開始繪制控件;先畫圓形,在圓形中心畫上文字;文字中心定位需要特别計算一下
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
public class OptionCircle extends ImageView {
private final Paint paint;
private final Context context;
boolean clicked = false;// 是否被點選
boolean addBackground = false;
int radius = -1; // 半徑值初始化為-1
int centerOffsetX = 0;// 圓圈原點的偏移量x
int centerOffsetY = 0;// 偏移量y
int colorCircle; // 圓圈顔色
int colorBackground; // 背景填充顔色
int colorText; // 文字顔色
String textCircle = "";
public OptionCircle(Context context) {
this(context, null);
}
public OptionCircle(Context context, AttributeSet attrs) {
super(context, attrs);
this.context = context;
this.paint = new Paint();
this.paint.setAntiAlias(true);
this.paint.setStyle(Paint.Style.STROKE);
colorCircle = Color.argb(205, 245, 2, 51);// 預設顔色
colorText = colorCircle; // 字型顔色預設與圈圈顔色保持一緻
colorBackground = colorCircle;// 設定預設參數
}
// 屬性設定方法
public void setRadius(int r) {
this.radius = r;
}
public void setCenterOffset(int x, int y) {
this.centerOffsetX = x;
this.centerOffsetY = y;
}
public void setColorCircle(int c) {
this.colorCircle = c;
}
public void setColorText(int c) {
this.colorText = c;
}
public void setColorBackground(int c) {
this.colorBackground = c;
}
public void setText(String s) {
this.textCircle = s;
}
public void setClicked(boolean clicked) {
this.clicked = clicked;
}
public void setAddBackground(boolean add) {
this.addBackground = add;
}
@Override
protected void onDraw(Canvas canvas) {
int center = getWidth() / 2;// 目前寬度的一半
int innerCircle = 86; // 預設半徑為86
if (radius > 0) {
innerCircle = dip2px(context, radius); // 如果沒有另外設定半徑,取半徑86
}
Drawable drawable = getDrawable();
if (addBackground) {
} else {
// 畫圈圈;被點選後會變成實心的圈圈,預設是空心的
this.paint.setStyle(clicked ? Paint.Style.FILL : Paint.Style.STROKE);
this.paint.setColor(clicked ? colorBackground : colorCircle);
this.paint.setStrokeWidth(1.5f);
canvas.drawCircle(center + centerOffsetX, center + centerOffsetY,
innerCircle, this.paint);// 畫圓圈時帶上偏移量
}
// 繪制文字
this.paint.setStyle(Paint.Style.FILL);
this.paint.setStrokeWidth(1);
this.paint.setTextSize(22);
this.paint.setTypeface(Typeface.MONOSPACE);// 設定一系列文字屬性
this.paint.setColor(clicked ? Color.WHITE : colorText);
this.paint.setTextAlign(Paint.Align.CENTER);// 文字水準居中
Paint.FontMetricsInt fontMetrics = paint.getFontMetricsInt();
canvas.drawText(textCircle, center + centerOffsetX,
center + centerOffsetY - (fontMetrics.top + fontMetrics.bottom) / 2, this.paint);// 設定文字豎直方向居中
super.onDraw(canvas);
}
/**
* convert dp to px
*/
public static int dip2px(Context context, float dpValue) {
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (dpValue * scale + 0.5f);
}
}
配置 activity_circle_choose.xml
控件檔案定義完畢,在
activity_circle_choose.xml
中配置一下
定義4個圈圈;center_circle定位在中心;circle_0是紅色的;circle_1是綠色的;circle_2是洋紅色的
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/top_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="5dp"
android:text="@string/circles_top_title"
android:textSize="26sp" />
<com.rust.aboutview.view.OptionCircle
android:id="@+id/center_circle"
android:layout_width="140dp"
android:layout_height="140dp"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true" />
<com.rust.aboutview.view.OptionCircle
android:id="@+id/circle_0"
android:layout_width="200dp"
android:layout_height="200dp"
android:layout_marginStart="130dp"
android:layout_marginTop="53dp" />
<com.rust.aboutview.view.OptionCircle
android:id="@+id/circle_1"
android:layout_width="210dp"
android:layout_height="210dp"
android:layout_below="@+id/circle_0"
android:layout_toEndOf="@+id/center_circle" />
<com.rust.aboutview.view.OptionCircle
android:id="@+id/circle_2"
android:layout_width="210dp"
android:layout_height="210dp"
android:layout_below="@id/center_circle" />
</RelativeLayout>
在 CirclesActivity.java 中使用圈圈
圈圈類
OptionCircle.java
已經開放了設定屬性的方法,我們可以利用這些方法來調整圈圈的樣式,比如半徑,顔色,圓心偏移量
center_circle固定在螢幕中間不動
circle_0仿造一個放大縮小的效果,改變半徑值即可實作
circle_1仿造一個浮動的效果,改變圓心偏移量來實作
circle_2仿造抖動效果,也是改變圓心偏移量
這些圈圈都可以自定義背景顔色
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import com.rust.aboutview.view.OptionCircle;
public class CirclesActivity extends Activity {
public static final String TAG = "CirclesActivity";
public static final int circle0_r = 88;
private static final int SLEEPING_PERIOD = 100; // 重新整理UI間隔時間
private static final int UPDATE_ALL_CIRCLE = 99;
int circleCenter_r;
int circle1_r;
boolean circle0Clicked = false;
boolean circle1Clicked = false;
OptionCircle centerCircle;
OptionCircle circle0;
OptionCircle circle1;
OptionCircle circle2;
CircleHandler handler = new CircleHandler(this);
/**
* Handler : 用于更新UI
*/
static class CircleHandler extends Handler {
CirclesActivity activity;
boolean zoomDir = true;
boolean circle2Shaking = false;
int r = circle0_r;
int moveDir = 0; // 浮動方向
int circle1_x = 0;// 偏移量的值
int circle1_y = 0;
int circle2_x = 0;
int circle2ShakeTime = 0;
int circle2Offsets[] = {10, 15, -6, 12, 0};// 抖動偏移量坐标
CircleHandler(CirclesActivity a) {
activity = a;
}
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case UPDATE_ALL_CIRCLE: {
if (zoomDir) {// 用簡單的辦法實作半徑變化
r++;
if (r >= 99) zoomDir = false;
} else {
r--;
if (r <= circle0_r) zoomDir = true;
}
activity.circle0.invalidate();
activity.circle0.setRadius(r);
calOffsetX();// 計算圓心偏移量
activity.circle1.invalidate();
activity.circle1.setCenterOffset(circle1_x, circle1_y);
if (circle2Shaking) {
if (circle2ShakeTime < circle2Offsets.length - 1) {
circle2ShakeTime++;
} else {
circle2Shaking = false;
circle2ShakeTime = 0;
}
activity.circle2.invalidate();
activity.circle2.setCenterOffset(circle2Offsets[circle2ShakeTime], 0);
}
}
}
}
// 計算circle1圓心偏移量;共有4個浮動方向
private void calOffsetX() {
if (moveDir == 0) {
circle1_x--;
circle1_y++;
if (circle1_x <= -6) moveDir = 1;
}
if (moveDir == 1) {
circle1_x++;
circle1_y++;
if (circle1_x >= 0) moveDir = 2;
}
if (moveDir == 2) {
circle1_x++;
circle1_y--;
if (circle1_x >= 6) moveDir = 3;
}
if (moveDir == 3) {
circle1_x--;
circle1_y--;
if (circle1_x <= 0) moveDir = 0;
}
}
}
class UpdateCircles implements Runnable {
@Override
public void run() {
while (true) {// 配合Handler,循環重新整理UI
Message message = new Message();
message.what = UPDATE_ALL_CIRCLE;
handler.sendEmptyMessage(message.what);
try {
Thread.sleep(SLEEPING_PERIOD); // 暫停
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_circle_choose);
centerCircle = (OptionCircle) findViewById(R.id.center_circle);
circle0 = (OptionCircle) findViewById(R.id.circle_0);
circle1 = (OptionCircle) findViewById(R.id.circle_1);
circle2 = (OptionCircle) findViewById(R.id.circle_2);
circleCenter_r = 38;
circle1_r = 45;
// 設定圈圈的屬性
centerCircle.setRadius(circleCenter_r);
centerCircle.setColorText(Color.BLUE);
centerCircle.setColorCircle(Color.BLUE);
centerCircle.setText("點選圈圈");
circle0.setColorText(Color.RED);
circle0.setRadius(circle0_r);
circle0.setText("RED");
circle1.setColorCircle(Color.GREEN);
circle1.setColorText(Color.GREEN);
circle1.setText("Green");
circle1.setRadius(circle1_r);
circle2.setColorCircle(getResources().getColor(R.color.colorMagenta));
circle2.setColorText(getResources().getColor(R.color.colorMagenta));
circle2.setText("Frozen!");
// 設定點選事件,可在這裡改變控件的屬性
circle0.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
circle0Clicked = !circle0Clicked; // 每次點選都取反
circle0.setClicked(circle0Clicked);
}
});
circle1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
circle1Clicked = !circle1Clicked;
circle1.setColorBackground(Color.GREEN);
circle1.setClicked(circle1Clicked);
}
});
circle2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
handler.circle2Shaking = true;// 顫抖吧!
}
});
Thread t = new Thread(new UpdateCircles());
t.start();// 開啟子線程
}
}
至此,圈圈demo結束。通過簡單的計算,模拟出浮動,抖動,縮放的效果
以上的代碼,複制粘貼進工程裡就能使用。圓心移動的軌迹,用三角函數來計算會更好
這裡繼承的是ImageView,應該有辦法在圈内動态添加背景Bitmap,效果更好看