Android kotlin 自定义圆形数字提示好点 兼容1到99+不变形 详细代码

以下是一个使用Kotlin编写的自定义圆形数字提示的示例代码，该代码可以兼容1到99+的数字，并保持圆形不变形。

首先，创建一个名为CircleBadgeView的自定义View类：

import android.content.Context
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.graphics.Rect
import android.util.AttributeSet
import android.view.View

class CircleBadgeView(context: Context, attrs: AttributeSet? = null) : View(context, attrs) {
    private val paint = Paint(Paint.ANTI_ALIAS_FLAG)
    private var text = ""
    private val textBounds = Rect()

    init {
        paint.color = Color.RED
        paint.style = Paint.Style.FILL
        paint.textSize = resources.getDimensionPixelSize(R.dimen.circle_badge_text_size).toFloat()
        paint.textAlign = Paint.Align.CENTER
    }

    fun setCount(count: Int) {
        text = if (count > 99) "99+" else count.toString()
        invalidate()
    }

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        val desiredWidth = MeasureSpec.getSize(widthMeasureSpec)
        val desiredHeight = MeasureSpec.getSize(heightMeasureSpec)
        val textHeight = paint.descent() - paint.ascent()
        val width = Math.max(desiredWidth, suggestedMinimumWidth) + paddingLeft + paddingRight
        val height = Math.max(desiredHeight, suggestedMinimumHeight) + paddingTop + paddingBottom + textHeight.toInt()
        setMeasuredDimension(width, height)
    }

    override fun onDraw(canvas: Canvas) {
        super.onDraw(canvas)

        val radius = Math.min(width, height) / 2f
        canvas.drawCircle(width / 2f, height / 2f, radius, paint)

        paint.color = Color.WHITE
        paint.getTextBounds(text, 0, text.length, textBounds)
        val x = width / 2f
        val y = height / 2f + (textBounds.bottom - textBounds.top) / 2f - textBounds.bottom
        canvas.drawText(text, x, y, paint)
    }
}

在上述代码中，我们定义了一个CircleBadgeView类，该类继承自View，并重写了onMeasure和onDraw方法。onMeasure方法用于计算View的宽度和高度，以确保View能够容纳文本和绘制的圆形背景。onDraw方法用于绘制圆形背景和文本。

接下来，在布局文件中使用CircleBadgeView:

<com.example.CircleBadgeView
    android:id="@+id/badgeView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="4dp"
    android:textColor="#FFFFFF"
    android:textSize="12sp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

最后，在Activity中设置圆形数字提示的数值：

val badgeView: CircleBadgeView = findViewById(R.id.badgeView)
badgeView.setCount(99)  // 设置提示数值为99

这样，就可以在布局中显示一个带有圆形背景的数字提示，并且可以根据需要设置不同的数值