优点
基本解决对齐方式,可以设置前缀隐藏和显示
/*** https://blog.csdn.net/u013982652/article/details/94404711* Android自定义TextView实现必填项前面的*号* 另一种实现方式(推荐使用这种,有非必填情况的话不会有对齐问题)* <p>* <cn.mvp.mlibs.weight.MiRequiredTextViewPro* android:layout_width="wrap_content"* android:layout_height="wrap_content"* android:paddingLeft="12dp"* android:text="Hello World!"* app:prefixText="c11 "* app:prefixTextColor="@color/red"* app:prefixVisibility="invisible" />*/
public class MiRequiredTextViewPro extends androidx.appcompat.widget.AppCompatTextView {private String prefixText;private int prefixTextColor;private int prefixVisibility;private int visible = 0, invisible = 1, gone = 2;public MiRequiredTextViewPro(Context context) {super(context);init(null);}public MiRequiredTextViewPro(Context context, AttributeSet attrs) {super(context, attrs);init(attrs);}public MiRequiredTextViewPro(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);init(attrs);}private void init(AttributeSet attrs) {if (attrs != null) {TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.CustomTextView);prefixText = a.getString(R.styleable.CustomTextView_prefixText);prefixTextColor = a.getColor(R.styleable.CustomTextView_prefixTextColor, Color.RED);prefixVisibility = a.getInt(R.styleable.CustomTextView_prefixVisibility, View.VISIBLE);a.recycle();}updatePrefixVisibility();updatePrefixText();updatePrefixTextColor();}private void updatePrefixText() {if (prefixText != null) {setText(prefixText + getText());}}private void updatePrefixTextColor() {if (prefixText == null) {return;}SpannableString spannableString = new SpannableString(getText());spannableString.setSpan(new ForegroundColorSpan(prefixTextColor), 0, prefixText.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);setText(spannableString);}/*** invisible:不显示,但是占位置* gone:彻底不显示,不占位置*/private void updatePrefixVisibility() {if (prefixVisibility == invisible) {Paint paint = new Paint();paint.setTextSize(getTextSize());float textWidth = paint.measureText(prefixText);prefixText = "";setPadding((int) textWidth + getPaddingLeft(), getPaddingTop(), getPaddingRight(), getPaddingBottom());} else if (prefixVisibility == gone) {prefixText = "";}}public void setPrefixText(String prefixText) {this.prefixText = prefixText;updatePrefixText();}public void setPrefixTextColor(int prefixTextColor) {this.prefixTextColor = prefixTextColor;updatePrefixTextColor();}public void setPrefixVisibility(int prefixVisibility) {this.prefixVisibility = prefixVisibility;updatePrefixVisibility();}
}样式
<declare-styleable name="CustomTextView"><attr name="prefixText" format="string" /><attr name="prefixTextColor" format="color" /><attr name="prefixVisibility"><enum name="visible" value="0" /><enum name="invisible" value="1" /><enum name="gone" value="2" /></attr></declare-styleable>
