本文共 7333 字，大约阅读时间需要 24 分钟。
1、设置XML布局
2、定义attrs.xml文件
3、自定义控件继承LinearLayout
public class LinesEditView extends LinearLayout { private Context mContext; private EditText mInputEt; private TextView mInputTv; private int MAX_COUNT; private String hintText; private int hintTextColor; private boolean ignoreCnOrEn; private String contentText; private int contentTextSize; private int contentTextColor; private float contentViewHeight; public LinesEditView(Context context) { this(context, null); } public LinesEditView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public LinesEditView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); mContext = context; TypedArray typedArray = context.obtainStyledAttributes(attrs,R.styleable.LinesEditView); MAX_COUNT = typedArray.getInteger(R.styleable.LinesEditView_lev_maxCount, 100); ignoreCnOrEn = typedArray.getBoolean(R.styleable.LinesEditView_lev_ignoreCnOrEn, true); hintText = typedArray.getString(R.styleable.LinesEditView_lev_hintText); hintTextColor = typedArray.getColor(R.styleable.LinesEditView_lev_hintTextColor, Color.parseColor("#42000000")); contentText = typedArray.getString(R.styleable.LinesEditView_lev_contentText); contentTextColor = typedArray.getColor(R.styleable.LinesEditView_lev_contentTextColor, Color.parseColor("#8A000000")); contentTextSize = typedArray.getDimensionPixelSize(R.styleable.LinesEditView_lev_contentTextSize, dp2px(context, 14)); contentViewHeight = typedArray.getDimensionPixelSize(R.styleable.LinesEditView_lev_contentViewHeight,dp2px(context, 140)); typedArray.recycle(); initView(); } private void initView() { View view = LayoutInflater.from(mContext).inflate(R.layout.layout_lines_edit_view, this); mInputEt = (EditText) view.findViewById(R.id.et_input); mInputTv = (TextView) view.findViewById(R.id.tv_input); if (this.getBackground() == null) { this.setBackgroundResource(R.drawable.selector_lines_edit_view_bg); } mInputEt.addTextChangedListener(mTextWatcher); mInputEt.setHint(hintText); mInputEt.setHintTextColor(hintTextColor); mInputEt.setText(contentText); mInputEt.setTextColor(contentTextColor); mInputEt.setTextSize(TypedValue.COMPLEX_UNIT_PX, contentTextSize); mInputEt.setHeight((int) contentViewHeight); /** * 配合 mInputTv xml的 android:focusable="true" android:focusableInTouchMode="true" 在iet_input设置完文本后 不给et_input 焦点 */ mInputTv.requestFocus(); configCount(); mInputEt.setSelection(mInputEt.length()); // 将光标移动最后一个字符后面 /** * focus后给背景设置Selected */ mInputEt.setOnFocusChangeListener(new OnFocusChangeListener() { @Override public void onFocusChange(View view, boolean b) { LinesEditView.this.setSelected(b); } }); } private TextWatcher mTextWatcher = new TextWatcher() { private int editStart; private int editEnd; @Override public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) { } @Override public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) { } @Override public void afterTextChanged(Editable editable) { editStart = mInputEt.getSelectionStart(); editEnd = mInputEt.getSelectionEnd(); // 先去掉监听器，否则会出现栈溢出 mInputEt.removeTextChangedListener(mTextWatcher); if (ignoreCnOrEn) { //当输入字符个数超过限制的大小时，进行截断操作 while (calculateLengthIgnoreCnOrEn(editable.toString()) > MAX_COUNT) { editable.delete(editStart - 1, editEnd); editStart--; editEnd--; } } else { // 因为是中英文混合，单个字符而言，calculateLength函数都会返回1 while (calculateLength(editable.toString()) > MAX_COUNT) { // 当输入字符个数超过限制的大小时，进行截断操作 editable.delete(editStart - 1, editEnd); editStart--; editEnd--; } } mInputEt.setSelection(editStart); // 恢复监听器 mInputEt.addTextChangedListener(mTextWatcher); configCount(); } }; private long calculateLength(CharSequence c) { double len = 0; for (int i = 0; i < c.length(); i++) { int tmp = (int) c.charAt(i); if (tmp > 0 && tmp < 127) { len += 0.5; } else { len++; } } return Math.round(len); } private int calculateLengthIgnoreCnOrEn(CharSequence c) { int len = 0; for (int i = 0; i < c.length(); i++) { len++; } return len; } private void configCount() { if (ignoreCnOrEn) { int nowCount = calculateLengthIgnoreCnOrEn(mInputEt.getText().toString()); mInputTv.setText(String.valueOf((nowCount)) + "/" + MAX_COUNT); } else { long nowCount = calculateLength(mInputEt.getText().toString()); mInputTv.setText(String.valueOf((nowCount)) + "/" + MAX_COUNT); } } private static int dp2px(Context context, float dp) { final float scale = context.getResources().getDisplayMetrics().density; return (int) (dp * scale + 0.5f); } public void setContentText(String content) { contentText = content; if (mInputEt == null) { return; } mInputEt.setText(contentText); } public String getContentText() { if (mInputEt != null) { contentText = mInputEt.getText() == null ? "" : mInputEt.getText().toString(); } return contentText; } public void setHintText(String hintText) { this.hintText = hintText; if (mInputEt == null) { return; } mInputEt.setHint(hintText); } public void setContentTextSize(int size) { if (mInputEt == null) { return; } mInputEt.setTextSize(TypedValue.COMPLEX_UNIT_PX, size); } public void setContentTextColor(int color) { if (mInputEt == null) { return; } mInputEt.setTextColor(color); } public void setHintColor(int color) { if (mInputEt == null) { return; } mInputEt.setHintTextColor(color); } public String getHintText() { if (mInputEt != null) { hintText = mInputEt.getHint() == null ? "" : mInputEt.getHint().toString(); } return hintText; } public void setMaxCount(int max_count) { this.MAX_COUNT = max_count; configCount(); } public void setIgnoreCnOrEn(boolean ignoreCnOrEn) { this.ignoreCnOrEn = ignoreCnOrEn; configCount(); }} 4、使用方法，直接在layout文件中引用自定义控件
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