我有一些EditText用于手机号码输入。应用必须为每个国家/地区添加唯例如，亚美尼亚必须添加+374，用户必须填写其他数字。 +374也必须是不可更改的，用户无法更改或删除它。这样做有什么办法吗？
编辑：
我不想将textView或其他视图与此文本一起使用并将其放在ediText的左侧。我希望通过较少的操作找到一些方法。我需要冻结文本，以便在用户删除其中的某些部分时不检查每个文本更改或添加缺少的文本。
创建一个自定义可绘制类，有助于将文本转换为drawable。
public class TextDrawable extends Drawable {
private final String text;
private final Paint paint;
public TextDrawable(String text) {
this.text = text;
this.paint = new Paint();
paint.setColor(Color.BLACK);
paint.setTextSize(16f);
paint.setAntiAlias(true);
paint.setTextAlign(Paint.Align.LEFT);
}
@Override
public void draw(Canvas canvas) {
canvas.drawText(text, 0, 6, paint);
}
@Override
public void setAlpha(int alpha) {
paint.setAlpha(alpha);
}
@Override
public void setColorFilter(ColorFilter cf) {
paint.setColorFilter(cf);
}
@Override
public int getOpacity() {
return PixelFormat.TRANSLUCENT;
}
}
然后将edittext的leftable设置为
EditText et = (EditText)findViewById(R.id.editText1);
String code = "+374";
et.setCompoundDrawablesWithIntrinsicBounds(new TextDrawable(code), null, null, null);
et.setCompoundDrawablePadding(code.length()*10);
edittext在布局文件中定义为
<EditText
android:id="@+id/editText1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="16sp"
android:ems="10" >
<requestFocus />
</EditText>
最终输出看起来像
public class MainActivity extends Activity {
private EditText editText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText = (EditText) findViewById(R.id.editText1);
editText.setText("+374");
Selection.setSelection(editText.getText(), editText.getText().length());
editText.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
// TODO Auto-generated method stub
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
if (!s.toString().startsWith("+374")) {
editText.setText("+374");
Selection.setSelection(editText.getText(), editText
.getText().length());
}
}
});
}
}
您可以创建类扩展AppCompatEditText或EditText。
public class CEditTextMaster extends AppCompatEditText {
private boolean isNeedNoChangeSomeCharacters;
private String charactersNoChange;
public CEditTextMaster(Context context) {
super(context);
init(context, null);
}
public CEditTextMaster(Context context, AttributeSet attrs) {
super(context, attrs);
init(context, attrs);
}
public CEditTextMaster(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context, attrs);
}
public void init(Context context, @Nullable AttributeSet attrs) {
if (isInEditMode())
return;
addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
@Override
public void afterTextChanged(Editable s) {
if (isNeedNoChangeSomeCharacters && charactersNoChange != null) {
if (!getText().toString().startsWith(charactersNoChange)) {
removeTextChangedListener(this);
if (charactersNoChange.length() > s.length()) {
setText(charactersNoChange);
} else {
setText(charactersNoChange + getText());
}
setSelection(getText().toString().length());
addTextChangedListener(this);
}
}
}
});
}
@Override
protected void onSelectionChanged(int selStart, int selEnd) {
if (isNeedNoChangeSomeCharacters && charactersNoChange != null) {
if (length() > charactersNoChange.length() && selStart < charactersNoChange.length()) {
setSelection(charactersNoChange.length(),selEnd);
}
}
}
@Override
public void setText(CharSequence text, BufferType type) {
super.setText(text, type);
if (isNeedNoChangeSomeCharacters && charactersNoChange != null) {
if (!getText().toString().trim().startsWith(charactersNoChange)) {
setText(charactersNoChange + getText());
}
}
}
public void setCharactersNoChangeInitial(String charactersNoChange) {
isNeedNoChangeSomeCharacters = true;
this.charactersNoChange = charactersNoChange;
if (!getText().toString().trim().startsWith(charactersNoChange)) {
setText(getText());
}
}
}
用来：
edt.setCharactersNoChangeInitial("+734 ");
使用文本观察器，当用户输入+3时，它以+374结束并比较前四个字符，如果相同，则禁用软键盘的后退，这样它就不会改变文本并输入附加的另一个数字。 textwatcher使用的文本
我选择了一个类似于另一个提交的解决方案，扩展EditText和修改onSelectionChanged。这可以防止用户甚至进入该区域。
这是我正在使用的：
import android.content.Context
import android.text.Editable
import android.util.AttributeSet
import androidx.appcompat.widget.AppCompatEditText
class PrefixEditText(context: Context, attrs: AttributeSet?) : AppCompatEditText(context, attrs) {
private var prefix: String? = null
fun setPrefix(prefix: String) {
this.prefix = prefix
setText(prefix)
addTextChangedListener(object : TextWatcher {
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) = Unit
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) = Unit
override fun afterTextChanged(s: Editable?) {
// Block deleting the prefix
if (s?.startsWith(prefix) == false) {
setText(prefix)
}
}
})
}
override fun onSelectionChanged(selStart: Int, selEnd: Int) {
var newStart = selStart
var newEnd = selEnd
prefix?.length?.let {
newStart = if (selStart < it) it else selStart
newEnd = if (selEnd < it) it else selEnd
}
if (selStart != newStart || selEnd != newEnd) {
setSelection(newStart, newEnd)
} else {
super.onSelectionChanged(selStart, selEnd)
}
}
// Here to conform to EditText's API
// Could also just override getText()
fun getPostText(): Editable? {
return prefix?.let {
Editable.Factory.getInstance().newEditable(text)?.delete(0, it.length)
} ?: run {
text
}
}
// Here for convenience, to avoid instantiating a new Editable, if the text is all you need
fun getPostCharSeq(): CharSequence? {
return prefix?.let {
text?.substring(it.length)
} ?: run {
text
}
}
}
通过测试：
import android.view.ViewGroup
import android.widget.FrameLayout
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.rule.ActivityTestRule
import com.roosterteeth.roosterteeth.TestActivity
import org.junit.Assert
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith
@RunWith(AndroidJUnit4::class)
class PrefixEditTextTest {
@Rule
@JvmField
var activityRule: ActivityTestRule<TestActivity> = ActivityTestRule(TestActivity::class.java, true, true)
private fun setupView(prefix: String, message: String): PrefixEditText {
val editText = PrefixEditText(activityRule.activity, null)
val lp = FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT)
activityRule.activity.addContentView(editText, lp)
editText.setPrefix(prefix)
editText.append(message)
return editText
}
@Test
fun testSelection() {
activityRule.runOnUiThread {
val prefix = "pre: "
val message = "hello world"
val editText = setupView(prefix, message)
editText.setSelection(0)
Assert.assertEquals(editText.selectionStart, prefix.length)
Assert.assertEquals(editText.selectionEnd, prefix.length)
editText.setSelection(0, editText.length())
Assert.assertEquals(editText.selectionStart, prefix.length)
Assert.assertEquals(editText.selectionEnd, editText.length())
}
}
@Test
fun testGetPostText() {
activityRule.runOnUiThread {
val prefix = "pre: "
val message = "hello world"
val editText = setupView(prefix, message)
Assert.assertEquals(message, editText.getPostText().toString())
// This test is after to make sure that getting the post text did not actually modify the contents
Assert.assertEquals("pre: $message", editText.text.toString())
}
}
@Test
fun testGetPostCharSeq() {
activityRule.runOnUiThread {
val prefix = "pre: "
val message = "hello world"
val editText = setupView(prefix, message)
Assert.assertEquals(message, editText.getPostCharSeq())
// This test is after to make sure that getting the post text did not actually modify the contents
Assert.assertEquals("pre: $message", editText.text.toString())
}
}
}