Question

我是MVC新手，我正在尝试为学校创建一个Color picker Android应用程序。目的是创建多个复合视图以显示相同的数据（红色，绿色和蓝色值）。我的问题是我应该如何使用TextWatcher来确定EditText字段何时被更改，然后根据字段的值更新所有视图。到目前为止，这是我的代码：

ColorModel.java

public class ETColorsCOMP extends ConstraintLayout implements Observer {
    private EditText etRed, etGreen, etBlue;
    private ColorModel model;

    public ETColorsCOMP(Context context) {
        super(context);
        init();
    }

    public ETColorsCOMP(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public ETColorsCOMP(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    public void init() {
        LayoutInflater inflater = (LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        inflater.inflate(R.layout.edittext_compound, this);

        etRed = findViewById(R.id.editTextRed);
        etGreen= findViewById(R.id.editTextGreen);
        etBlue = findViewById(R.id.editTextBlue);
    }

    public void setColorModel(ColorModel model) {
        this.model = model;
        this.model.addObserver(this);
    }

    @Override
    public void update(Observable observable, Object o) {
        etRed.setText(model.getRed());
        etGreen.setText(model.getGreen());
        etBlue.setText(model.getBlue());
    }
}

ETColorsCOMP.java （3个EditTexts的复合体）

public class VColorCOMP extends ConstraintLayout implements Observer {
    private ColorModel model;
    private View vRed, vGreen, vBlue;

    public VColorCOMP(Context context) {
        super(context);
        init();
    }

    public VColorCOMP(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public VColorCOMP(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    public void init() {
        LayoutInflater inflater = (LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        inflater.inflate(R.layout.colorview_compound, this);

        vRed = findViewById(R.id.ViewRed);
        vGreen = findViewById(R.id.ViewGreen);
        vBlue = findViewById(R.id.ViewBlue);
    }

    public void setColorModel(ColorModel model) {
        this.model = model;
        this.model.addObserver(this);
    }

    @Override
    public void update(Observable observable, Object o) {
        vRed.setBackgroundColor(Color.rgb(model.getRed(), 0, 0));
        vGreen.setBackgroundColor(Color.rgb(0, model.getGreen(), 0));
        vBlue.setBackgroundColor(Color.rgb(0, 0, model.getBlue()));
    }
}

VColorsCOMP.java （3个View组件的组合）

public class MainActivity extends AppCompatActivity {

    private ETColorsCOMP etColors;
    private VColorCOMP vColor;

    private ColorModel colorModel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        etColors = findViewById(R.id.editTextView);
        vColor = findViewById(R.id.colorView);

        colorModel = new ColorModel();
        etColors.setColorModel(colorModel);
        vColor.setColorModel(colorModel);
    }
}

MainActivity.java

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如果有人帮我完成这项工作，我将非常感激。

Answer 1

您可以在TextWatcher的 afterTextChanged 方法上编写代码。

editText.addTextChangedListener(new TextWatcher() {
            @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) {
                // Update UI
            }
        });

（MVC）在Compound视图上实现TextWatcher

1 个答案: