C# PropertyDescriptorCollection.RemoveAt方法代码示例

        /// <summary>
        /// This is overridden to return a property descriptors for the object represented by this type
        /// descriptor along with extra property descriptors for its child properties.
        /// </summary>
        /// <param name="attributes">An array of attributes to use as a filter or null for no filter</param>
        /// <returns>Returns a <see cref="PropertyDescriptorCollection"/> that contains property descriptors for
        /// the object and its child properties.</returns>
        public override PropertyDescriptorCollection GetProperties(Attribute[] attributes)
        {
            // This seems to ignore the filter so GetChildProperties() will get rid of all non-browsable
            // properties.
            PropertyDescriptorCollection props = base.GetProperties(attributes);
            List<PropertyDescriptor> newProps = new List<PropertyDescriptor>();

            this.GetChildProperties(null, String.Empty, attributes, props, newProps);

            if(newProps.Count != 0)
            {
                // The collection is read-only so we'll need to create a new one
                PropertyDescriptor[] tempProps = new PropertyDescriptor[props.Count + newProps.Count];

                props.CopyTo(tempProps, 0);
                newProps.CopyTo(tempProps, props.Count);

                props = new PropertyDescriptorCollection(tempProps);

                // Now we'll remove hidden top-level properties
                for(int idx = 0; idx < props.Count; idx++)
                    if(props[idx].Attributes[typeof(HidePropertyAttribute)] != null)
                    {
                        props.RemoveAt(idx);
                        idx--;
                    }
            }

            return props;
        }

		private void AssertReadOnly (PropertyDescriptorCollection descriptors, string testCase)
		{
			MockPropertyDescriptor mockPropertyDescr = new MockPropertyDescriptor (
				"Date", DateTime.Now);

			try {
				descriptors.Add (mockPropertyDescr);
				Assert.Fail (testCase + "#1");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			// ensure read-only check if performed before value is checked
			try {
				descriptors.Add (null);
				Assert.Fail (testCase + "#2");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			try {
				descriptors.Clear ();
				Assert.Fail (testCase + "#3");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			try {
				descriptors.Insert (0, mockPropertyDescr);
				Assert.Fail (testCase + "#4");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			// ensure read-only check if performed before value is checked
			try {
				descriptors.Insert (0, null);
				Assert.Fail (testCase + "#5");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			try {
				descriptors.Remove (mockPropertyDescr);
				Assert.Fail (testCase + "#6");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			// ensure read-only check if performed before value is checked
			try {
				descriptors.Remove (null);
				Assert.Fail (testCase + "#7");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			try {
				descriptors.RemoveAt (0);
				Assert.Fail (testCase + "#8");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			IList list = (IList) descriptors;
			Assert.IsTrue (((IList) descriptors).IsReadOnly, testCase + "#9");
			Assert.IsTrue (((IList) descriptors).IsFixedSize, testCase + "#10");

			try {
				list.Add (mockPropertyDescr);
				Assert.Fail (testCase + "#11");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			// ensure read-only check if performed before value is checked
			try {
				list.Add (null);
				Assert.Fail (testCase + "#12");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			try {
				list.Clear ();
				Assert.Fail (testCase + "#13");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			try {
				list.Insert (0, mockPropertyDescr);
				Assert.Fail (testCase + "#14");
			} catch (NotSupportedException) {
				// read-only collection cannot be modified
			}

			// ensure read-only check if performed before value is checked
			try {
				list.Insert (0, null);
//.........这里部分代码省略.........