Question

朋友我是Android编程的新手，我想了解我们如何选择文本并将所选文本返回到String中。

Answer 1

如果要从EditText中选择文本，可以使用：

String selectedText = editText.getText().substring(startSelection, endSelection);

其中：

int startSelection=editText.getSelectionStart();
int endSelection=editText.getSelectionEnd();

但是，如果您有TextView，则需要在选择文本时创建自己的ActionMode.Callback。要查看快速示例，请转到此post。

Answer 2

这里是一个快速示例，您可以选择文本并使用Toast将其显示在屏幕上：

MainActivity

public class MainActivity extends AppCompatActivity {
private static final int TRANSLATE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final TextView mTextView = (TextView) findViewById(R.id.txt);

    mTextView.setCustomSelectionActionModeCallback(new ActionMode.Callback() {
        @Override
        public boolean onCreateActionMode(ActionMode mode, Menu menu) {
            menu.add(0,TRANSLATE,0,"Translate").setIcon(R.drawable.ic_translate); //choose any icon
            // Remove the other options
            menu.removeItem(android.R.id.selectAll);
            menu.removeItem(android.R.id.cut);
            menu.removeItem(android.R.id.copy);
            return true;
        }

        @Override
        public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
            return true;
        }

        @Override
        public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
            switch (item.getItemId()){
                case TRANSLATE:
                    int min = 0;
                    int max = mTextView.getText().length();
                    if (mTextView.isFocused()) {
                        final int selStart = mTextView.getSelectionStart();
                        final int selEnd = mTextView.getSelectionEnd();

                        min = Math.max(0, Math.min(selStart, selEnd));
                        max = Math.max(0, Math.max(selStart, selEnd));
                    }

                    final CharSequence selectedText = mTextView.getText().subSequence(min, max); //this is your desired string
                    Toast.makeText(getApplicationContext(),selectedText,Toast.LENGTH_SHORT).show();

                    //Here put your code for translation

                    mode.finish();
            }
            return false;
        }

        @Override
        public void onDestroyActionMode(ActionMode mode) {

        }
    });
}

XML：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

<TextView
    android:textIsSelectable="true"
    android:id="@+id/txt"
    android:text="@string/hello_world" android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

Android在String中获取所选文本

2 个答案: