我正在使用EditText，它可以采用此question中提到的粗体，斜体和下划线字符。
我扩展了EditText并覆盖了onTextChanged（）方法。 我的代码适用于任何粗体，斜体，下划线输入的第一次出现，但在我第二次出现后，第一次出现的内容变为普通文本。
Here is a gif depecting the problem
这是MainActivity.java
package com.example.syed.andtexteditor;
import android.os.Bundle;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
int helperCounterB = 0;
int helperCounterI = 0;
int helperCounterU = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button boldButton = (Button) findViewById(R.id.bold_button);
boldButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Button boldButton = (Button) findViewById(R.id.bold_button);
helperCounterB++;
if (helperCounterB % 2 != 0)
//The EditText is in Bold mode when the Bold button is pressed odd-th time
boldButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.black));
else
boldButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.grey));
TextArea t = (TextArea) findViewById(R.id.textInput);
t.applyTypeface(helperCounterI, helperCounterB, helperCounterU);
}
});
Button italicsButton = (Button) findViewById(R.id.italics_button);
italicsButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Button italicsButton = (Button) findViewById(R.id.italics_button);
helperCounterI++;
if (helperCounterI % 2 != 0) //The EditText is in Italics mode when the Italics button is pressed odd-th time
italicsButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.black));
else
italicsButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.grey));
TextArea t = (TextArea) findViewById(R.id.textInput);
t.applyTypeface(helperCounterI, helperCounterB, helperCounterU);
}
});
Button underlineButton = (Button) findViewById(R.id.underline_button);
underlineButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Button underlineButton = (Button) findViewById(R.id.underline_button);
helperCounterU++;
if (helperCounterU % 2 != 0)//The EditText is in Underline mode when the Underline button is pressed odd-th time
underlineButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.black));
else
underlineButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.grey));
TextArea t = (TextArea) findViewById(R.id.textInput);
t.applyTypeface(helperCounterI, helperCounterB, helperCounterU);
}
});
}
}
这是扩展的EditText类，即TextArea.java
package com.example.syed.andtexteditor;
import android.content.Context;
import android.graphics.Typeface;
import android.support.v7.widget.AppCompatEditText;
import android.text.Editable;
import android.text.Spannable;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.TextUtils;
import android.text.style.CharacterStyle;
import android.text.style.StyleSpan;
import android.text.style.UnderlineSpan;
import android.util.AttributeSet;
import android.util.Log;
/**
* Created by Syed on 29-05-2017.
*/
public class TextArea extends AppCompatEditText {
Context c;
public static final int TYPEFACE_NORMAL = 0;
public static final int TYPEFACE_BOLD = 1;
public static final int TYPEFACE_ITALICS = 2;
public static final int TYPEFACE_BOLD_ITALICS = 3;
public static final int TYPEFACE_UNDERLINE = 4;
public static final int TYPEFACE_BOLD_UNDERLINE = 5;
public static final int TYPEFACE_ITALICS_UNDERLINE = 6;
public static final int TYPEFACE_BOLD_ITALICS_UNDERLINE = 7;
private int currentTypeface;
private int lastCursorPosition;
private StyleSpan normalspan = new StyleSpan(Typeface.NORMAL);
private StyleSpan boldspan = new StyleSpan(Typeface.BOLD);
private StyleSpan italicspan = new StyleSpan(Typeface.ITALIC);
private StyleSpan boldItalicspan = new StyleSpan(Typeface.BOLD_ITALIC);
private UnderlineSpan underlinespan = new UnderlineSpan();
public TextArea(Context context) {
super(context);
c = context;
lastCursorPosition = this.getSelectionStart();
}
public TextArea(Context context, AttributeSet attrs) {
super(context, attrs);
}
public void changeTypeface(int tfId) {
currentTypeface = tfId;
lastCursorPosition = this.getSelectionStart();
}
public void applyTypeface(int helperCounterI, int helperCounterB, int helperCounterU) {
int min = 0;
int max = this.getText().length();
if (this.isFocused()) {
final int selStart = this.getSelectionStart();
final int selEnd = this.getSelectionEnd();
min = Math.max(0, Math.min(selStart, selEnd));
max = Math.max(0, Math.max(selStart, selEnd));
}
Spannable s = this.getText();
Editable selectedText = new SpannableStringBuilder(s, min, max);
SpannableStringBuilder s1 = new SpannableStringBuilder(s, 0, min);
String selectedTextString = selectedText.toString();
SpannableStringBuilder selectedSpannedString = new SpannableStringBuilder(selectedTextString);
Log.d(VIEW_LOG_TAG, "Helper Counter I: " + helperCounterI + " Helper Counter B: " + helperCounterB);
if (helperCounterI % 2 != 0 && helperCounterB % 2 != 0 && helperCounterU % 2 == 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TextArea.TYPEFACE_BOLD_ITALICS);
}
//ignore this part as there are no issues with this
else {
StyleSpan styleSpan = new StyleSpan(Typeface.BOLD_ITALIC);
selectedSpannedString.setSpan(styleSpan, min, max, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterI % 2 != 0 && helperCounterB % 2 == 0 && helperCounterU % 2 == 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TextArea.TYPEFACE_ITALICS);
}
//ignore this part as there are no issues with this
else {
StyleSpan styleSpan = new StyleSpan(Typeface.ITALIC);
selectedSpannedString.setSpan(styleSpan, min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterI % 2 == 0 && helperCounterB % 2 != 0 && helperCounterU % 2 == 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TextArea.TYPEFACE_BOLD);
}
//ignore this part as there are no issues with this
else {
StyleSpan styleSpan = new StyleSpan(Typeface.BOLD);
selectedSpannedString.setSpan(styleSpan, min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterB % 2 == 0 && helperCounterI % 2 == 0 && helperCounterU % 2 == 0) {
this.changeTypeface(TextArea.TYPEFACE_NORMAL);
} else if (helperCounterU % 2 != 0 && helperCounterI % 2 == 0 && helperCounterB % 2 == 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TYPEFACE_UNDERLINE);
}
//ignore this part as there are no issues with this
else {
selectedSpannedString.setSpan(new UnderlineSpan(), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterU % 2 != 0 && helperCounterI % 2 == 0 && helperCounterB % 2 != 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TYPEFACE_BOLD_UNDERLINE);
}
//ignore this part as there are no issues with this
else {
selectedSpannedString.setSpan(new StyleSpan(Typeface.BOLD), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
selectedSpannedString.setSpan(new UnderlineSpan(), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterU % 2 != 0 && helperCounterI % 2 != 0 && helperCounterB % 2 == 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TYPEFACE_ITALICS_UNDERLINE);
} else
//ignore this part as there are no issues with this
{
selectedSpannedString.setSpan(new StyleSpan(Typeface.ITALIC), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
selectedSpannedString.setSpan(new UnderlineSpan(), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterU % 2 != 0 && helperCounterI % 2 != 0 && helperCounterB % 2 != 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TYPEFACE_BOLD_ITALICS_UNDERLINE);
}
//ignore this part as there are no issues with this
else {
selectedSpannedString.setSpan(new StyleSpan(Typeface.BOLD_ITALIC), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
selectedSpannedString.setSpan(new UnderlineSpan(), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
}
}
@Override
protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
Log.d(VIEW_LOG_TAG, "Start: " + start + " Length before: " + lengthBefore + " Length After: " + lengthAfter + " TextLength: " + text.length());
CharacterStyle ss = null;
UnderlineSpan ss1 = null;
int endLength = text.toString().length();
switch (currentTypeface) {
case TYPEFACE_NORMAL:
ss = normalspan;
break;
case TYPEFACE_BOLD:
ss = boldspan;
break;
case TYPEFACE_ITALICS:
ss = italicspan;
break;
case TYPEFACE_BOLD_ITALICS:
ss = boldItalicspan;
break;
case TYPEFACE_UNDERLINE:
ss = underlinespan;
break;
case TYPEFACE_BOLD_UNDERLINE:
ss = boldspan;
ss1 = underlinespan;
break;
case TYPEFACE_ITALICS_UNDERLINE:
ss = italicspan;
ss1 = underlinespan;
break;
case TYPEFACE_BOLD_ITALICS_UNDERLINE:
ss = boldItalicspan;
ss1 = underlinespan;
break;
}
if (lastCursorPosition > endLength)
return;
Log.d(TextArea.class.getSimpleName(), new Integer(lastCursorPosition).toString() + new Integer(endLength).toString());
this.getText().setSpan(ss, lastCursorPosition, endLength, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
this.getText().setSpan(ss1, lastCursorPosition, endLength, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
}
}
答案 0 :(得分：1)
您的问题是您正在重新使用跨度的实例。根据{{3}}（强调我的）的文档：
将指定的标记对象附加到文本的范围开始...结尾，或将对象移动到该范围（如果已经附加在其他地方）。
因此，每次要归档文本时，只需创建新的Spans。
希望有所帮助！