react-native有IllegalArgumentException("Cannot get layout margins of multi-edge shorthands")报错是怎么回事

报错的原因

这个错误通常是由于在Java代码中使用了React Native中不支持的布局属性导致的。例如，使用了"margin"而不是"marginTop"、"marginBottom"、"marginLeft"和"marginRight"。在React Native中，这些属性是不受支持的，因此会导致IllegalArgumentException。

如何解决

解决这个错误的方法是更改Java代码中使用的布局属性。将"margin"替换为"marginTop"、"marginBottom"、"marginLeft"和"marginRight"即可。

例如：

// 错误代码
ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
params.setMargins(20, 20, 20, 20);

// 正确代码
ViewGroup.MarginLayoutParams params = new ViewGroup.MarginLayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
params.setMargins(20, 20, 20, 20);

或者

ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
((ViewGroup.MarginLayoutParams) params).leftMargin = 20;
((ViewGroup.MarginLayoutParams) params).rightMargin = 20;
((ViewGroup.MarginLayoutParams) params).topMargin = 20;
((ViewGroup.MarginLayoutParams) params).bottomMargin = 20;

这样就能解决这个问题了。

使用例子

以下是一个使用React Native在Java代码中设置视图外边距的示例：

import com.facebook.react.uimanager.ThemedReactContext;
import com.facebook.react.uimanager.ViewGroupManager;
import android.view.ViewGroup;
import android.widget.LinearLayout;

public class MyViewManager extends ViewGroupManager {

  @Override
  public String getName() {
    return "MyView";
  }

  @Override
  protected LinearLayout createViewInstance(ThemedReactContext reactContext) {
    LinearLayout view = new LinearLayout(reactContext);

    // 错误代码
    // ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
    // params.setMargins(20, 20, 20, 20);

    //正确代码
    ViewGroup.MarginLayoutParams params = new ViewGroup.MarginLayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
    params.setMargins(20, 20, 20, 20);
    view.setLayoutParams(params);
    return view;
  }
}

或者

import com.facebook.react.uimanager.ThemedReactContext;
import com.facebook.react.uimanager.ViewGroupManager;
import android.view.ViewGroup;
import android.widget.LinearLayout;

public class MyViewManager extends ViewGroupManager {

  @Override
  public String getName() {
    return "MyView";
  }

  @Override
  protected LinearLayout createViewInstance(ThemedReactContext reactContext) {
    LinearLayout view = new LinearLayout(reactContext);

    ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
    ((ViewGroup.MarginLayoutParams) params).leftMargin = 20;
    ((ViewGroup.MarginLayoutParams) params).rightMargin = 20;
    ((ViewGroup.MarginLayoutParams) params).topMargin = 20;
    ((ViewGroup.MarginLayoutParams) params).bottomMargin = 20;

    view.setLayoutParams(params);
    return view;
  }
}

这样就能成功设置外边距，并避免出现"Cannot get layout margins of multi-edge shorthands"错误。