我想让复选框变得更小/更大,应该如何实现?
我找到了一种方法,可以在不创建自己的图像的情况下完成操作。换句话说,系统图像被缩放了。我并不是说这个解决方案完美无缺;如果有人知道如何缩短其中的一些步骤,那么我会很高兴地了解如何做到。
首先,在项目(WonActivity)的主活动类中放置以下内容。这直接来自于Stack Overflow - 谢谢你们!
/** get the default drawable for the check box */
Drawable getDefaultCheckBoxDrawable()
{
int resID = 0;
if (Build.VERSION.SDK_INT <= 10)
{
// pre-Honeycomb has a different way of setting the CheckBox button drawable
resID = Resources.getSystem().getIdentifier("btn_check", "drawable", "android");
}
else
{
// starting with Honeycomb, retrieve the theme-based indicator as CheckBox button drawable
TypedValue value = new TypedValue();
getApplicationContext().getTheme().resolveAttribute(android.R.attr.listChoiceIndicatorMultiple, value, true);
resID = value.resourceId;
}
return getResources().getDrawable(resID);
}
其次,我创建了一个用于“缩放可绘制对象”的类。请注意,它与标准的ScaleDrawable完全不同。
import android.graphics.drawable.*;
/** The drawable that scales the contained drawable */
public class ScalingDrawable extends LayerDrawable
{
/** X scale */
float scaleX;
/** Y scale */
float scaleY;
ScalingDrawable(Drawable d, float scaleX, float scaleY)
{
super(new Drawable[] { d });
setScale(scaleX, scaleY);
}
ScalingDrawable(Drawable d, float scale)
{
this(d, scale, scale);
}
/** set the scales */
void setScale(float scaleX, float scaleY)
{
this.scaleX = scaleX;
this.scaleY = scaleY;
}
/** set the scale -- proportional scaling */
void setScale(float scale)
{
setScale(scale, scale);
}
// The following is what I wrote this for!
@Override
public int getIntrinsicWidth()
{
return (int)(super.getIntrinsicWidth() * scaleX);
}
@Override
public int getIntrinsicHeight()
{
return (int)(super.getIntrinsicHeight() * scaleY);
}
}
import android.graphics.*;
import android.graphics.drawable.Drawable;
import android.widget.*;
/** A check box that resizes itself */
public class WonCheckBox extends CheckBox
{
/** the check image */
private ScalingDrawable checkImg;
/** original height of the check-box image */
private int origHeight;
/** original padding-left */
private int origPadLeft;
/** height set by the user directly */
private float height;
WonCheckBox()
{
super(WonActivity.W.getApplicationContext());
setBackgroundColor(Color.TRANSPARENT);
// get the original drawable and get its height
Drawable origImg = WonActivity.W.getDefaultCheckBoxDrawable();
origHeight = height = origImg.getIntrinsicHeight();
origPadLeft = getPaddingLeft();
// I tried origImg.mutate(), but that fails on Android 2.1 (NullPointerException)
checkImg = new ScalingDrawable(origImg, 1);
setButtonDrawable(checkImg);
}
/** set checkbox height in pixels directly */
public void setHeight(int height)
{
this.height = height;
float scale = (float)height / origHeight;
checkImg.setScale(scale);
// Make sure the text is not overlapping with the image.
// This is unnecessary on Android 4.2.2, but very important on previous versions.
setPadding((int)(scale * origPadLeft), 0, 0, 0);
// call the checkbox's internal setHeight()
// (may be unnecessary in your case)
super.setHeight(height);
}
}
就这样。如果您在视图中放置一个 WonCheckBox 并应用 setHeight(),则复选框图像的大小将是正确的。
假设您的原始XML如下:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_checked="true"
android:drawable="@drawable/tick_img" />
<item android:state_checked="false"
android:drawable="@drawable/untick_img" />
</selector>
然后在您的复选框xml中简单地删除android:button="@drawable/xml_above"
,并在Java中以编程方式进行可绘制缩放(将150
大尺寸减小到所需的dp大小):
CheckBox tickRememberPasswd = findViewById(R.id.remember_tick);
//custom selector size
Drawable drawableTick = ContextCompat.getDrawable(this, R.drawable.tick_img);
Drawable drawableUntick = ContextCompat.getDrawable(this, R.drawable.untick_img);
Bitmap bitmapTick = null;
if (drawableTick != null && drawableUntick != null) {
int desiredPixels = Math.round(convertDpToPixel(150, this));
bitmapTick = ((BitmapDrawable) drawableTick).getBitmap();
Drawable dTick = new BitmapDrawable(getResources()
, Bitmap.createScaledBitmap(bitmapTick, desiredPixels, desiredPixels, true));
Bitmap bitmapUntick = ((BitmapDrawable) drawableUntick).getBitmap();
Drawable dUntick = new BitmapDrawable(getResources()
, Bitmap.createScaledBitmap(bitmapUntick, desiredPixels, desiredPixels, true));
final StateListDrawable statesTick = new StateListDrawable();
statesTick.addState(new int[] {android.R.attr.state_checked},
dTick);
statesTick.addState(new int[] { }, //else state_checked false
dUntick);
tickRememberPasswd.setButtonDrawable(statesTick);
}
convertDpToPixel
方法:
public static float convertDpToPixel(float dp, Context context) {
Resources resources = context.getResources();
DisplayMetrics metrics = resources.getDisplayMetrics();
float px = dp * (metrics.densityDpi / 160f);
return px;
}
<CheckBox
android:layout_width="22dp"
android:layout_height="22dp"
android:layout_marginLeft="-10dp"
android:button="@null"
android:background="@drawable/memory_selector"/>